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November 3, 2020
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https://www.sciencedaily.com/releases/2020/11/201103172611.htm
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Lion genetics study uncovers major consequences of habitat fragmentation
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Over the course of only a century, humanity has made an observable impact on the genetic diversity of the lion population. That's the conclusion of a recently published study by Drs. Caitlin Curry and James Derr from the Texas A&M University College of Veterinary Medicine & Biomedical Sciences.
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By comparing the DNA of lions today to lions from 100 years ago, they found that there is clear genetic evidence of recent population fragmentation, which is when groups of a species are isolated from each other. This fragmentation could ultimately have a long-term impact on the genetic health of the iconic species. The research was published in the journal "I was surprised at what we found -- surprised and disappointed, because it's not what I wanted to see," Derr said. "I really wanted to be able to tell everyone that the management we've been doing for the last 100 years is perfect and to keep doing what we've been doing and everything will be fine. But that's not the take-home lesson; unfortunately, that's not the story we can tell.Curry and Derr started their study with one overarching question: Has the genetic structure of lion populations changed over the last 100 years?There have been several studies on modern lions, so gathering data for the modern populations was straightforward. Curry pulled together DNA data from three previously published studies on lions that lived between 1990-2012.The historical populations, against which they wanted to compare the modern lion DNA, provided more of a challenge. Fortunately, scientists have a way to turn back time. Many of those lion remains still reside perfectly preserved in collections around the world. Curry used DNA extracted from bones, teeth and hides of 143 lions that lived between 1880-1949 to create a historical population data set.Both population data sets cover the same geographical range from India to Southern Africa where lions are found. Scientists call this type of analysis, comparing data from the same space at different times, a spatiotemporal study.It has been understood for a long time that female lions tend to stay close to the pride in which they were born, while males travel great distances to find new prides. Therefore, males are almost exclusively responsible for the movement of genes in the population, which helps keep genetic diversity within the species high.As the human population continues to rapidly grow across Africa and more and more barriers to lion movement have gone up in the form of cities, fences and farmland, male lions haven't been able to travel the distances they once could.According to Curry, while lions are still genetically diverse right now, the results in the DNA were more pronounced than she expected."In the historical population, you couldn't easily identify where a lion was from based on its nuclear DNA. This is due to high historical levels of gene flow across the population," she said. "But in the modern population, you can determine the general area, or sub-population, for most of the lions. But, even with sub-populations being more isolated, the overall level of genetic diversity is still considered high across all lion populations."If lions are still generally genetically healthy today, then why does this matter?"Over the last 100 years or so, we have restricted the natural movements of many species," Derr said. "This isolation leads to reduced gene flow and ultimately may result in reducing genetic diversity to a level that threatens the survival of local populations."Perhaps the most well-known example of what happens with a lack of genetic diversity is another large cat, the African cheetah.According to genetic analysis, scientists believe cheetahs have suffered two large bottleneck events, or events that lead to a rapid shrinking of the gene pool. When these events happen, it results in the breeding of closely related individuals in the population, or inbreeding, creating very low genetic diversity.This has led to a current cheetah population that, even in the wild, struggles to fend off new diseases, has difficulty breeding, and faces other significant health problems.But that fate can still be avoided in lions, especially now that experts are armed with proof that lion populations have been significantly impacted by isolation and subdivision."This should not be a disheartening story but rather one of hope," Curry said. "Yes, we see a decrease in genetic diversity across lion populations over the past century. But, currently, compared with other mammalian species, lion genetic diversity is still considered high across all lion populations."With responsible management focused on giving prides enough space to breed and allowing males to move more freely between isolated pockets, it is possible to increase the genetic diversity and reduce population sub-division across lion populations."There have been multiple reintroduction programs bringing lions back to areas where lions once roamed, and coexistence strategies are increasingly being integrated into wildlife conservation programs."The positive take-home message is now that we've documented this and we understand it, policies can be tailored to manage these populations differently," Derr said. "We know now that you can't treat all lions the same. Now we have the responsibility to manage these animals, and many other managed wildlife species, in ways that better reflects their current biology."
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November 3, 2020
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https://www.sciencedaily.com/releases/2020/11/201103104732.htm
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Buffalo fly faces Dengue nemesis
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Few beef producers in the temperate climate of southern Australia will have encountered the parasitic buffalo fly (Haematobia irritans exigua), a scourge of the cattle industry in the country's tropical and subtropical north -- but maintaining this state of affairs, and also lifting a burden off the northern industry, has become a race against time, and climate.
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Buffalo fly is a serious animal health and production challenge, costing the northern Australian cattle industry almost $100 million a year in treatments and lost production. But control of the pest with insecticides is running into increasing resistance, plus there is a need to protect Australian beef's 'clean green' reputation and so minimise the need for pesticides.Over the past century the buffalo fly has been creeping southwards through Queensland to northern New South Wales and modelling shows that, aided by climate change, it could reach as far south as South Australia and south-west Western Australia by 2030. The blood-sucking fly causes large, painful sores and distressed animals can be distracted from feeding enough to seriously affect growth.The only obstacle in its path is a joint university, industry and Queensland Government biological control project using the insect-infecting bacterium, Wolbachia -- the same agent that has been used so successfully to suppress mosquito-transmitted dengue fever in humans.The project is led by Dr Peter James from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) at The University of Queensland, who explains the key is using the Wolbachia bacterium to break the fly's breeding cycle. If this can be sustained it presents an opportunity to both suppress the buffalo fly population in the north and stop its spread southwards.The buffalo fly is a formidable foe, having been introduced from Asia into the Northern Territory in the late 1830s, but the chink in its armour is it weakens in cold weather. Its populations tend to shrink into localised pockets. Dr James says if Wolbachia can be used to further stress the buffalo fly in winter, then a local eradication strategy starts to become a real possibility.But there are some considerable technical challenges still to overcome. Because the bacterium is spread vertically from mother to offspring, not transferred sideways amongst flies, buffalo flies have to be artificially infected by microinjection. With mosquitoes, this is usually done by microinjection into the eggs. That approach hasn't been able to be used for buffalo fly because the eggs are extremely hard: "When we started micro-injecting eggs, as is done with mosquitoes, we were blunting needles and damaging the eggs like you wouldn't believe. Needles were even breaking," says Dr James."So from there we looked at micro-injecting adult flies or pupae, the idea being the bacterium would still spread through the insect and get into the germinal tissue of the females."He says the main thing is to establish the bacterium in the population because once flies are infected, three control scenarios open up. While Wolbachia is a maternally transmitted bacterium, through eggs, male flies can still be used to manipulate this.If a Wolbachia infected male mates with a healthy female the eggs will be infertile and so no offspring. Conversely, if a healthy male mates with an infected female the mating will be successful with eggs and offspring produced, but they will be carrying Wolbachia and help to spread it through the buffalo fly population. Dr James says the advantage of this is that it saves researchers having to otherwise breed and release millions of infected or sterile flies."But Wolbachia also has a whole lot of other impacts on fly population fitness. We have shown that just the presence of the bacterium can shorten the buffalo flies' lifespan, reduce the number of eggs laid, and the number of pupae that hatch. There are probably also other fitness penalties that we haven't yet identified. If you start to add up all these impacts, that can be a heavy load on survivability."And this is where the winter factor comes. In many areas the buffalo fly only just hangs on in low numbers through winter so even Wolbachia's effect on population fitness could be enough to wipe out these populations if the bacterium is deployed strategically."A second approach is to use Wolbachia to block transmission of the Stephanofilaria nematode transmitted by buffalo flies and associated with the development of buffalo fly lesions on the cattle. Similar to the way that Wolbachia blocks transmission of dengue virus, zika virus and a number of other viruses transmitted by mosquitoes, it has also been shown to block transmission of some nematodes closely related to Stephanofilaria. Spread of Wolbachia through the buffalo fly population could block the nematode and alleviate lesion developmentA third option being explored is to breed and release sterile males."Again, the idea is to use the sterile males strategically by releasing them into those overwintering areas that are already in a weakened state. This could stop or slow the build-up of buffalo fly in the next season or stop the southerly spread or even provide the basis of local eradication strategies."Dr James says the challenge now is to improve the consistency and persistence of Wolbachia infection. Since the Wolbachia project started in 2017 researchers have achieved the first big challenge of taking different Wolbachia strains from mosquitoes and also fruit fly and introducing them into a whole new species, the buffalo fly: "Wolbachia has been carried across generations in a number of instances, but we have yet to produce a stably infected strain," he explains."But we have reached the stage where we can start finessing the approach. For example we have a project looking at ways to immunosuppress the fly to favour Wolbachia infection."We've built up a reasonable toolbox so I am confident we are close to providing sustainable biological control that will deliver economic animal welfare relief to the northern cattle industry, and save the southern industry from ever having to endure the same burden."
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Animals
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November 2, 2020
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https://www.sciencedaily.com/releases/2020/11/201102162647.htm
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Lizard skull fossil is new and 'perplexing' extinct species
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In 2017, while browsing the fossil collections of Yale's Peabody Museum of Natural History, University of Texas at Austin graduate student Simon Scarpetta came across a small lizard skull, just under an inch long.
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The skull was beautifully preserved, with a mouth full of sharp teeth -- including some with a distinctive curve.Much to Scarpetta's surprise, no one had studied it. Since being discovered in 1971 on a museum fossil hunting trip to Wyoming, the 52 million-year-old skull had sat in the specimen drawer."Lizards are small and prone to breaking apart, so you mostly get these individual, isolated fragmented bones," said Scarpetta, who is studying paleontology at the UT Jackson School of Geosciences. "Anytime you find a skull, especially when you're trying to figure out how things are related to each other, it's always an exciting find."Scarpetta decided to bring the skull back to the Jackson School for a closer look. And on September 2020, the journal The first part of the name references the lizard's distinct teeth; a "kopis" is a curved blade used in ancient Greece. But the second part is a nod to the "perplexing" matter of just where the extinct lizard should be placed on the tree of life. According to an analysis conducted by Scarpetta, the evidence points to a number of plausible spots.The spots can be divided into two groups of lizards, representing two general hypotheses of where the new species belongs. But adding to the uncertainty is that how those two groups relate to one another can shift depending on the particular evolutionary tree that's examined. Scarpetta examined three of these trees -- each one built by other researchers studying the evolutionary connections of different reptile groups using DNA -- and suggests that there could be a forest of possibilities where the ancient lizard could fit.The case of where exactly to put the perplexing lizard highlights an important lesson for paleontologists: just because a specimen fits in one place doesn't mean that it won't fit equally well into another."The hypothesis that you have about how different lizards are related to each other is going to influence what you think this one is," Scarpetta said.Paleontologists use anatomical details present in bones to discern the evolutionary relationships of long-dead animals. To get a close look at the lizard skull, Scarpetta created a digital scan of it in the Jackson School's High-Resolution X-Ray CT Lab. However, while certain details helped identify the lizard as a new species, other details overlapped with features from a number of different evolutionary groups.All of these groups belonged to a larger category known as Iguania, which includes a number of diverse species, including chameleons, anoles and iguanas. To get a better idea of where the new species might fit into the larger Iguania tree, Scarpetta compared the skull data to evolutionary trees for Iguania that were compiled by other researchers based on DNA evidence from living reptiles.On each tree, the fossil fit equally well into two general spots. What's more, the lizard groupings in each spot varied from tree to tree. If Scarpetta had just stopped at one spot or one tree, he would have missed alternative explanations that appear just as plausible as the others.Scarpetta said that "Something that I think the broader scientific community should pull from this is that you have to be realistic about your data and acknowledge what we can actually pull from our results and conclude and where there are still uncertainties," Lively said. "Simon's approach is the high bar, taking the high road. It's acknowledging what we don't know and really embracing that."The research was funded by the Jackson School of Geosciences and the Geological Society of America.
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Animals
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November 2, 2020
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https://www.sciencedaily.com/releases/2020/11/201102150842.htm
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Bats can predict the future, researchers discover
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They can't tell fortunes and they're useless with the stock market but bats are quite skilled at predicting one thing: where to find dinner.
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Bats calculate where their prey is headed by building on-the-fly predictive models of target motion from echoes, Johns Hopkins University researchers find. The models are so robust, bats can continue to track prey even when it temporarily vanishes behind echo-blocking obstacles like trees.Although predicting object motion paths through vision has been extensively studied, these findings, published today in the journal "Just the way a tennis player needs to find out when and where they will hit the ball, a bat needs to anticipate when and where it will make contact with the insect it's hunting," said senior author Cynthia F. Moss, a neuroscientist and professor of Psychological and Brain Sciences. "The insect is flying. The bat is also flying. In this very rapidly changing environment, if the bat were to just rely on the information it got from the most recent echo, it would miss the insect."The bat uses the time delay between each echolocation call and the resulting echoes to determine how far away prey is. They tilt their heads to catch the changing intensity of echoes to figure out where the prey is in the horizontal plane. Bats must put together echo information about object distance and direction to successfully track an erratic moving insect.But because bats are such good hunters, the research team thought that in addition, the bats must also be somehow using this information to predict where they prey is headed. To test this in the lab, they designed an experiment that closely mirrored the situation of a bat hunting in the wild.They trained bats to stay on a perch and track insects. The team recorded the bat's echolocation calls and head movements as they changed where the insects moved and how quickly. They also added obstacles that interrupted the echoes."We devised mathematical models to test the data and we came up with different hypotheses of what the bats could be doing," said co-first author Clarice Anna Diebold, a doctoral candidate in Psychological and Brain Sciences.If that bat wasn't predicting where the insect would be, its head movements would always lag behind the target. But that wasn't the case. If the bat kept his head in a fixed position, which sometimes reflected where the insect ended up, that would eliminate the prediction theory. But that wasn't happening either. And if the bat was only using information from the echoes to estimate velocity, that wouldn't be enough to explain the extent of the bat's precision."We hypothesized that bats use both the velocity information from the timing of the echoes and further adjust their head aim," said co-first author Angeles Salles, a postdoctoral fellow. "When we tested this model with our data, we saw it fit very well."The findings upend the previous accepted notion that bats do not predict an insect's future position -- a conclusion largely drawn from a 1980s study done before high-speed video was widely available."The question of prediction is important because an animal must plan ahead to decide what it's going to do next," said Salles. "A visual animal or a human has a stream of information coming in, but for bats it's remarkable because they're doing this with only brief acoustic snapshots."Although bats are studied here, the findings apply to any animals that track moving sounds, and even to people, like the blind, who use clicks and cane taps to help them navigate while avoiding obstacles.This work was funded by Human Frontiers Science Program Fellowship LT000220/2018; NSF Fellowship GRFP 2018261398; NSF Brain Initiative Grant NCS-FO 1734744 (2017- 2021); AFOSR Grant FA9550-14-1-0398NIFTI; and ONR Grant N00014-17-1- 2736.
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Animals
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November 2, 2020
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https://www.sciencedaily.com/releases/2020/11/201102120055.htm
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New study finds earliest evidence for mammal social behavior
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A new study led by paleontologists at the University of Washington and its Burke Museum of Natural History & Culture indicates that the earliest evidence of mammal social behavior goes back to the Age of Dinosaurs.
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The evidence, published Nov. 2 in the journal Fossil skulls and skeletons of at least 22 individuals of "It was crazy finishing up this paper right as the stay-at-home orders were going into effect -- here we all are trying our best to socially distance and isolate, and I'm writing about how mammals were socially interacting way back when dinosaurs were still roaming the Earth!" said Weaver. "It is really powerful, I think, to see just how deeply rooted social interactions are in mammals. Because humans are such social animals, we tend to think that sociality is somehow unique to us, or at least to our close evolutionary relatives, but now we can see that social behavior goes way further back in the mammalian family tree. Multituberculates are one of the most ancient mammal groups, and they've been extinct for 35 million years, yet in the Late Cretaceous they were apparently interacting in groups similar to what you would see in modern-day ground squirrels."Previously, scientists thought social behavior in mammals first emerged after the mass extinction that killed off the dinosaurs, and mostly in the Placentalia -- the group of mammals humans belong to, which all carry the fetus in the mother's uterus until a late stage of development. But these fossils show mammals were socializing during the Age of Dinosaurs, and in an entirely different and more ancient group of mammals -- the multituberculates."These fossils are game changers," said Wilson Mantilla. "As paleontologists working to reconstruct the biology of mammals from this time period, we're usually stuck staring at individual teeth and maybe a jaw that rolled down a river, but here we have multiple, near complete skulls and skeletons preserved in the exact place where the animals lived. We can now credibly look at how mammals really interacted with dinosaurs and other animals that lived at this time."
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Animals
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November 2, 2020
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https://www.sciencedaily.com/releases/2020/10/201030111830.htm
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Drones as stinger spotters
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Researchers from James Cook University in Cairns have demonstrated, for the first time, the potential for off-the-shelf drones to be used to detect deadly box jellyfish.
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The research, published today in the journal ""Drone surveillance could help make our beaches safer, and reduce our reliance on time-consuming drag netting by life savers."Ms Rowley and colleagues from the Australian Institute of Tropical Health and Medicine set out to establish the reliability of lower-cost domestic drones in detecting these large, near-transparent jellyfish."The attraction of these devices is that they are more affordable, easily transported, and easier to use," Ms Rowley said."They don't require as much training and licensing as the higher-end versions and a large number of surf lifesaving clubs, particularly in Australia, already have them in their kit for rip identification, and crocodile and shark spotting."The researchers tested the drones' accuracy as jellyfish spotters in waters near Weipa on Cape York Peninsula. They deployed 70-metre nets, and then recorded drone footage before pulling in the nets and counting and measuring any jellyfish.During the experiment the drone pilot kept records of jellyfish spotted during each flight. These records were later compared with the netted numbers, and with the accuracy achieved in a lab-based review of the footage.The researchers confirmed that reviewing footage after the flights led to significantly high detection rates. They also quantified the effects of weather conditions such as cloud cover and wind on the drones' success rate."This has huge implications. Most, if not all, beaches worldwide, from Japan to Europe and beyond, have issues with very harmful jellyfish and presently there is no way of telling if animals are there until someone gets stung," Ms Rowley said."This project really highlights the capacity for drones as early warning systems. Using drones is fast, effective and cheap and helps keep those on the front line out of the water and out of harm's way."The next stage of the project will see this research trialled with Surf Life Saving hubs along the Queensland coast. The trials are funded by the Australian Lions Foundation and will begin in the next month.
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Animals
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November 2, 2020
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https://www.sciencedaily.com/releases/2020/11/201102120110.htm
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Beetle larvae think with brain 'under construction'
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In the human brain, hundreds of billions of nerve cells are interconnected in the most complicated way, and only when these interconnections are correctly made, can the brain function properly. This is no different for insects, even though their brains consist of 'only' one hundred thousand to one million nerve cells. Nevertheless, fascinating and unexpectedly complicated behaviour can be observed in insects, for example when rearing offspring in the bee hive or when mosquitoes search for blood. To a large extent, the brain develops in the embryo, but in many animals it is completed only after birth. Now, biologists from the University of Göttingen have found out that beetle larvae start using their brains, although still 'under construction'. The results have been published in the journal
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The biologists compared the development of the brains of flies and beetles, focusing on the "central complex" -- a structure in the brain that insects need for their orientation in the environment. Using genetic engineering methods and genome editing, they first marked the same small group of nerve cells in both the fruit fly and the red flour beetle. This enabled them to follow the development of these cells from embryo to adult animal under the microscope and to compare the development between the animal species. Even before these investigations, it was known that part of the central complex is already formed in the beetle larvae, whereas in flies it only develops in the adult animal. It was thought that the completed development of this part was required to allow the beetle larva to walk; fly maggots do not need this part because they have no legs.To their surprise, however, the scientists found that this part of the brain starts to work in the beetle larva, even though it has not yet reached a state similar to the adult animal. On the contrary -- the structure corresponds to an embryonic stage of development known from other insects. The difference is that in the beetle larva the nerve cells of this brain 'under construction' are already forming connections, which probably helps the larva to orientate itself in its environment. "I had expected to find a miniature version of the adult central complex -- but not that their 'construction site' would have started working," says Max Farnworth, first author and PhD student in Evolutionary Development Genetics at the University of Göttingen, expressing his surprise.The second big surprise was that the sequence of the brain's developmental steps had changed in the beetle. Previously, it was thought that the developmental steps always proceeded in the same order -- although the point in time when the step occurs may shift. This is known as 'heterochrony' in evolutionary biology. However, in the embryo of the beetle, some developmental steps changed their position to occur earlier in the series than in the fly. This was observed, for instance, with respect to the formation of crossings of nerve cells and the formation of synapses, while other steps took place later, just like in the fly."We have discovered the first example of a change in the developmental order in the brain, known as a 'sequence heterochrony'," explains senior author Professor Gregor Bucher, the Head of Evolutionary Developmental Genetics. "The development of insect brains is probably much more variable than we could have imagined. This could explain how they were able to adapt their brains in so many different ways to the demands of the environment."
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Animals
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October 30, 2020
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https://www.sciencedaily.com/releases/2020/10/201030144850.htm
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First Australian night bees recorded foraging in darkness
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Australian bees are known for pollinating plants on beautiful sunny days, but a new study has identified two species that have adapted their vision for night-time conditions for the first time.
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The study by a team of ecology researchers has observed night time foraging behaviour by a nomiine (Reepenia bituberculata) and masked (Meroglossa gemmata) bee species, with both developing enlarged compound and simple eyes which allow more light to be gathered when compared to their daytime kin.Published in the Lead author PhD Candidate James Dorey, in the College of Science & Engineering at Flinders University, says the two Australian bee species active at night and during twilight hours are mostly found in Australia's tropical north, but there could potentially more in arid, subtropical and maybe even temperate conditions across the continent."We have confirmed the existence of at least two crepuscular bee species in Australia and there are likely to be many more that can forage both during the day and into the early morning or evening under low light conditions. It's true that bees aren't generally known to be very capable when it comes to using their eyes at night, but it turns out that low-light foraging is more common than currently thought," says Mr Dorey."Before this study, the only way to show that a bee had adapted to low-light was by using difficult-to-obtain behavioural observations, but we have found that you should be able to figure this out by using high-quality images of a specific bee."Mr Dorey says bees that forage during dim-light conditions aren't studied enough with no previously reliable published records for any Australian species."Our study provides a framework to help identify low-light-adapted bees and the data that is needed to determine the behavioural traits of other species. This is important as we need to increase efforts to collect bee species outside of normal hours and publish new observations to better understand the role that they play in maintaining ecosystems."The researchers outline why more needs to be understood about the behaviour of bee species to help protect them from the potential impacts of climate change."Global weather patterns are changing and temperatures in many parts of Australia are rising along with the risk of prolonged droughts and fires. So, we have to improve our understanding about insects pollinating at night or in milder parts of the day to avoid potential extinction risks or to mitigate loss of pollination services.""This also means we have to highlight the species that operate in a narrow window of time and could be sensitive to climatic changes, so conservation becomes an important concern. Because quite frankly, we have ignored these species up until now."
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Animals
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October 30, 2020
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https://www.sciencedaily.com/releases/2020/10/201030122534.htm
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New synthetic DNA vaccine against Powassan virus
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Scientists at The Wistar Institute have designed and tested the first-of-its-kind synthetic DNA vaccine against Powassan virus (POWV), targeting portions of the virus envelope protein. A rapidly reemerging tick-borne disease, POWV has been reported to be fatal in 10% of infected people with detrimental neurological consequences including encephalitis and meningitis. This new POWV vaccine candidate, described in a paper published today in PLOS Neglected Infectious Diseases, is one of many emerging infectious disease DNA vaccine discoveries being advanced by the Vaccine and Immunotherapy Center at The Wistar Institute.
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Unlike the widely recognized Lyme disease, POWV causes a little known, potentially deadly infectious disease that is transmitted through tick bites during fall and spring seasons. POWV is an RNA virus belonging to the flavivirus family, the same as Zika virus, but passed to people by ticks instead of mosquitoes.Transmission can occur rapidly and symptoms including flu-like fever, body aches, skin rash, and headaches can present anytime during the 1-4 week incubation period. Although still considered relatively rare, in recent years the number of reported cases of people sick from Powassan virus has been increasing in North America, including infecting former U.S. Senator Kay Hagan who contracted Powassan virus and died from the disease. There are no vaccines or therapies available to treat or prevent this emerging infection.Kar Muthumani, Ph.D., former associate professor and director of the Laboratory of Emerging Infectious Diseases at The Wistar Institute, and senior author on the study, collaborated with the laboratory of David B. Weiner, Ph.D., executive vice president and director of Wistar's Vaccine and Immunotherapy Center, to design and test this synthetic DNA vaccine.The effectiveness of this vaccine was evaluated in preclinical studies that showed a single immunization elicited broad T and B cell immune responses in mice similar to those induced naturally in POWV-infected individuals, and that vaccine-induced immunity provided protection in a POWV challenge animal model."The significant protection in mice demonstrated by our vaccine is highly encouraging and strongly supports the importance of this vaccine approach for further study," said Muthumani.Residents of and visitors in POWV-endemic areas are considered at risk of infection, especially during outdoor work and recreational activities. In the U.S., cases of POWV disease have been reported in Northeastern states and the Great Lakes region."Given the risk of serious complications from POWV and the 300% increase in incidence of POWV infection over the past 16 years, we will continue efforts to advance this urgently needed emerging infectious disease vaccine candidate towards the clinic," said Weiner.
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Animals
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October 29, 2020
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https://www.sciencedaily.com/releases/2020/10/201029142025.htm
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Touch and taste? It's all in the tentacles
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Octopuses have captured the human imagination for centuries, inspiring sagas of sea monsters from Scandinavian kraken legends to TV's "Voyage to the Bottom of the Sea" and, most recently, Netflix's less-threatening "My Octopus Teacher." With their eight suction-cup covered tentacles, their very appearance is unique, and their ability to use those appendages to touch and taste while foraging further sets them apart.
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In fact, scientists have wondered for decades how those arms, or more specifically the suction cups on them, do their work, prompting a number of experiments into the biomechanics. But very few have studied what is happening on a molecular level. In a new report, Harvard researchers got a glimpse into how the nervous system in the octopus' arms (which operate largely independently from its centralized brain) manage this feat.The work published Thursday in The scientists identified a novel family of sensors in the first layer of cells inside the suction cups that have adapted to react and detect molecules that don't dissolve well in water. The research suggests these sensors, called chemotactile receptors, use these molecules to help the animal figure out what it's touching and whether that object is prey."We think because the molecules do not solubilize well, they could, for instance, be found on the surface of octopuses' prey and [whatever the animals touch]," said Nicholas Bellono, an assistant professor of molecular and cellular biology and the study's senior author. "So, when the octopus touches a rock versus a crab, now its arm knows, 'OK, I'm touching a crab [because] I know there's not only touch but there's also this sort of taste.'"In addition, scientists found diversity in what the receptors responded to and the signals they then transmitted to the cell and nervous systems."We think that this is important because it could facilitate complexity in what the octopus senses and also how it can process a range of signals using its semi-autonomous arm nervous system to produce complex behaviors," Bellono said.The scientists believe this research can help uncover similar receptor systems in other cephalopods, the invertebrate family that also includes squids and cuttlefish. The hope is to determine how these systems work on a molecular level and answer some relatively unexplored questions about how these creatures' capabilities evolved to suit their environment."Not much is known about marine chemotactile behavior and with this receptor family as a model system, we can now study which signals are important for the animal and how they can be encoded," said Lena van Giesen, a postdoctoral fellow in the Bellono Lab and lead author of the paper. "These insights into protein evolution and signal coding go far beyond just cephalopods."Along with Giesen, other co-authors from the lab include Peter B. Kilian, an animal technician, and Corey A.H. Allard, a postdoctoral fellow."The strategies they have evolved in order to solve problems in their environment are unique to them and that inspires a great deal of interest from both scientists and non-scientists alike," Kilian said. "People are drawn to octopuses and other cephalopods because they are wildly different from most other animals."The team set out to uncover how the receptors are able to sense chemicals and detect signals in what they touch, like a tentacle around a snail, to help them make choices.Octopus arms are distinct and complex. About two-thirds of an octopus's neurons are located in their arms. Because the arms operate partially independently from the brain, if one is severed it can still reach for, identify, and grasp items.The team started by identifying which cells in the suckers actually do the detecting. After isolating and cloning the touch and chemical receptors, they inserted them in frog eggs and in human cell lines to study their function in isolation. Nothing like these receptors exists in frog or human cells, so the cells act essentially like closed vessels for the study of these receptors.The researchers then exposed those cells to molecules such as extracts from octopus prey and others items to which these receptors are known to react. Some test subjects were water-soluble, like salts, sugars, amino acids; others do not dissolve well and are not typically considered of interest by aquatic animals. Surprisingly, only the poorly soluble molecules activated the receptors.Researchers then went back to the octopuses in their lab to see whether they too responded to those molecules by putting those same extracts on the floors of their tanks. They found the only odorants the octopuses receptors responded to were a non-dissolving class of naturally occurring chemicals known as terpenoid molecules."[The octopus] was highly responsive to only the part of the floor that had the molecule infused," Bellono said. This led the researchers to believe that the receptors they identified pick up on these types of molecules and help the octopus distinguish what it's touching. "With the semi-autonomous nervous system, it can quickly make this decision: 'Do I contract and grab this crab or keep searching?'"While the study provides a molecular explanation for this aquatic touch-taste sensation in octopuses through their chemotactile receptors, the researchers suggest further study is needed, given that a great number of unknown natural compounds could also stimulate these receptors to mediate complex behaviors."We're now trying to look at other natural molecules that these animals might detect," Bellono said.This research was supported by the New York Stem Cell Foundation, the Searle Scholars Program, the Sloan Foundation, the Klingenstein-Simons Fellowship, the National Institutes of Health, and the Swiss National Science Foundation.
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October 29, 2020
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https://www.sciencedaily.com/releases/2020/10/201029115812.htm
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Buzz kill: Ogre-faced spiders 'hear' airborne prey with their legs
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In the dark of night, ogre-faced spiders with dominating big eyes dangle from a silk frame to cast a web and capture their ground prey. But these spiders also can capture insects flying behind them with precision, and Cornell University scientists have now confirmed how.
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In a new study, researchers confirmed these spiders use metatarsal sensitivity -- sensors at the tip of the leg -- to detect sound cues of various frequencies from up to 6 feet away. These cues trigger a split-second, ninja-like backflip to strike unsuspecting airborne insects, bag them in a web net, and then dine."These spiders have finely tuned sensory systems and a fascinating hunting strategy," said lead author Jay Stafstrom, a postdoctoral researcher in the laboratory of Ronald Hoy, professor of neurobiology and behavior at Cornell. "These spiders have massive eyes so they can see at night and catch things off the ground, but they can 'hear' quite well, detecting sounds through their metatarsal organ, as these spiders excel at catching things from the air."Net-casting, ogre-faced spiders (Spiders don't have ears, but they can sense a wide range of sounds thanks to the metatarsal organ located near the tip of their legs.Stafstrom collected these spiders and brought them to Gil Menda, a postdoctoral researcher in Hoy's lab, who recorded neural activity from both their brains and their legs. He played pure tone frequencies to the spiders and noted the spider's neurons became excited for difference tones.Stafstrom examined frequencies that ranged from 150 Hz (the flute-like sound of blowing over a glass soda bottle) to 750 Hz (the high-pitched drone of a local television nighttime sign-off) to 10 Khz, a piercing, high-pitched sound."While the spiders were sensitive to low-frequency tones, as expected, we didn't really expect to see net-casting spiders sensitive to a wide range of frequencies -- all the way to 10 kilohertz," he said.
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October 29, 2020
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https://www.sciencedaily.com/releases/2020/10/201029105009.htm
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Individual red foxes prefer different foods in the city and the countryside
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Foxes are considered to be particularly adaptable and suited to life in large cities. A team of scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in cooperation with the Berlin-Brandenburg State Laboratory has now deciphered an important aspect of these adaptations. Using stable isotope analysis, they showed that individual red foxes (Vulpes vulpes) have a much narrower diet than might be expected from their omnivorous habits. The population of country foxes had a much broader diet than their urban conspecifics, whose diet differed little between individuals. The diet of urban and country foxes showed little overlap. This combination of specialisation and flexibility is a key to this omnivore's adaptability, according to a paper published in the scientific journal
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The diet is crucial to the survival of any animal. Using stable isotope analysis, the team led by first author Carolin Scholz (Leibniz-IZW) has now decoded the dietary spectrum of individual foxes in urban and rural areas. The results confirmed that red foxes are omnivorous and can feed on a wide variety of different animals and plants. At the same time, the results showed two different sets of specialisations: "Firstly, the diet of country foxes was much more varied than that of urban foxes," explains Scholz. "We detected a broad diet in foxes in unsealed habitats, ranging from plants, molluscs and insects to larger prey items. In contrast, urban foxes probably take advantage of the benefits of big city life and mainly fed on food items with increased ?13C values, an indication of food thrown away by people." Secondly, the isotope analyses confirmed that every fox is picky and specialises on particular food items, whether in the city or in the country. So, although the population of country foxes has a broad diet, each country fox follows quite a one-sided diet. City foxes celebrate a double monotony at the dinner table: both individuals and the population as a whole very often eat (different kinds of) discarded food.The red fox's ability to eat almost anything is certainly a key to success in conquering urban habitats. The fact that urban foxes all eat more or less the same food probably also indicates that there is plenty for all of them, says Scholz. "Obviously there is enough for everyone. We city dwellers set their table abundantly -- with leftover food, waste, compost and pet food."
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Animals
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October 28, 2020
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https://www.sciencedaily.com/releases/2020/10/201028195617.htm
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Secret surfing life of remoras hitchhiking on blue whales
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Sticking to the bodies of sharks and other larger marine life is a well-known specialty of remora fishes (Echeneidae) and their super-powered suction disks on their heads. But a new study has now fully documented the "suckerfish" in hitchhiking action below the ocean's surface, uncovering a much more refined skillset that the fish uses for navigating intense hydrodynamics that come with trying to ride aboard a 100-ft. blue whale (Balaenoptera musculus).
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In a study published Oct. 28 in the The study shows the secrets behind the remora fish's success in hitchhiking aboard baleen whales more than 30 times their size to safely traverse the ocean -- they select the most flow-optimal regions on the whale's body to stick to, such as behind the whale's blowhole, where drag resistance for the fish is reduced by as much as 84%. The team's findings also show that remoras can freely move around to feed and socialize on their ride even as their whale host hits burst speeds of more than 5 meters per second, by utilizing previously unknown surfing and skimming behaviors along special low-drag traveling lanes that exist just off the surface of the whale's body.Researchers say the study represents the highest-resolution whole-body fluid dynamic analysis of whales to date, the insights from which could potentially be used as a basis to better understand the behavior, energy use and overall ecological health of the species, as well as improve tagging and tracking of whales and other migratory animals in future studies."Whales are like their own floating island, basically like their own little ecosystems. ...To get a look into the flow environment of blue whales within a millimeter resolution through this study is extremely exciting," said Brooke Flammang, assistant professor of biology at New Jersey Institute of Technology and the study's corresponding author. "Through lucky coincidence, our recordings captured how remoras interact in this environment and are able to use the distinct flow dynamics of these whales to their advantage. It is incredible because we've really known next to nothing about how remoras behave on their hosts in the wild over any prolonged period of time."Until now, scientists studying the symbiotic relationships between remoras and their hosts in their natural ocean habitat have predominantly relied on still images and anecdotal evidence, leaving much of how they go about their renown sticking behavior beneath the surface a mystery.In their recent investigation, the researchers employed multi-sensor biologging tags with dual cameras that they attached to the whales via four 2-inch suction disks. The tags were able to calculate various measurements inside the whale's ecosystem, such as surface pressure and complex fluid forces around the whales, as well as GPS location and traveling speeds through tag vibrations, all while video recording the remoras at 24 frames per second and 720p resolution."Fortunately, the drag on dimple-shaped airplane cockpits has been measured many times and we were able to apply this knowledge to help figure out the drag these remoras were experiencing," said Erik Anderson, co-author, biofluid dynamics researcher at Grove City College and guest investigator at the Woods Hole Oceanographic Institution. "But our study still required calculating, for the first time ever, the flow over a blue whale using computational fluid dynamics ... it took an international team of biologists, programmers, engineers and a supercomputer to do that."The team's 211 minutes of video footage and whale tag data processed by researchers at the Barcelona Supercomputing Center captured a total of 27 remoras at 61 locations on the whales overall, finding that the remoras were most often podding and traveling between three of the most hydrodynamically beneficial spots where separating flow and wakes are caused by the whale's distinct topographical features: directly behind the blowhole, next to and behind the dorsal fin, and the flank region above and behind the pectoral fin.According to the team's measurements, Anderson says that the shear force experienced by an average-sized remora in the wake behind the blow hole of a whale swimming at the casual speed of 1.5 m/s can be as low as 0.02 Newtons, half the force of drag in the free stream above. However, Anderson notes that the average remora's suction force of 11-17 Newtons is more than a match for even the most intense parking spot on the whale, its tail, where the remora experiences roughly 0.14 Newtons of shear force. And though the forces are greater, the same is true even for large remora riding on whales swimming at much higher speeds."We learned that the remora's suction disk is so strong that they could stick anywhere, even the tail fluke where the drag was measured strongest, but they like to go for the easy ride," said Erik Anderson. "This saves them energy and makes life less costly as they hitchhike on and skim over the whale surface like a NASA probe over an asteroid or some mini-world."The tags showed that to conserve energy while getting about on their floating island, the remoras take advantage of the whale's physics by surfing inside a thin layer of fluid surrounding the whale's body, known as a boundary layer, where the team found drag force is reduced by up to 72% compared to the much more forceful free stream just above. Flammang says the fishes can lift within 1cm from their host in this layer to feed or join their mates at other low-drag social spots on the whale, occasionally changing directions by skimming, or repeatedly attaching and releasing their suction disks on the whale's body.Flammang suspects that remoras are able to move freely without being completely peeled from their speedy hosts, which can move nearly seven times faster than the remora, through something called the Venturi effect."The skimming and surfing behavior is amazing for many reasons, especially because we think that by staying about a centimeter off the whale body, they are taking advantage of the Venturi effect and using suction forces to maintain their close proximity," explained Flammang. "In this narrow space between the remora and whale, when fluid is funneled into a narrow space it moves at a higher velocity but has lower pressure, so it is not going to push the remora away but can actually suck it toward the host. They can swim up into the free stream to grab a bite of food and come back down into the boundary layer, but it takes a lot more energy to swim in the free stream flow."Along with uncovering new details of the remora's hitchhiking prowess, the team says they will continue to explore both the flow environments around whales and the mechanisms by which specifically adapted organisms like remoras successfully attach to hosts in order to improve animal tag technologies and designs for extended periods of behavioral and ecological monitoring. The team is also using their new insights into the remora's preferred low-drag attachment locations to better inform where they might tag whales in studies to come."It's an extremely arduous process to study whales what with permitting, research regulations and the game of chance of finding animals, all for the tags to usually fall off within 48 hours," said Flammang. "If we can come up with a better way to collect longer term data through better tag placement or better technologies, it could really advance our learning of the species, and many other animals that remoras attach to."
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October 28, 2020
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https://www.sciencedaily.com/releases/2020/10/201028195608.htm
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Ancient marine predator had a built-in float
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About 240 million years ago, when reptiles ruled the ocean, a small lizard-like predator floated near the bottom of the edges in shallow water, picking off prey with fang-like teeth. A short and flat tail, used for balance, helps identify it as a new species, according to research published in the
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Paleontologists at the Chinese Academy of Scientists and Canadian Museum of Nature have analysed two skeletons from a thin layer of limestone in two quarries in southwest China. They identified the skeletons as nothosaurs, Triassic marine reptiles with a small head, fangs, flipper-like limbs, a long neck, and normally an even longer tail, probably used for propulsion. However, in the new species, the tail is short and flat."Our analysis of two well-preserved skeletons reveals a reptile with a broad, pachyostotic body (denser boned) and a very short, flattened tail. A long tail can be used to flick through the water, generating thrust, but the new species we've identified was probably better suited to hanging out near the bottom in shallow sea, using its short, flattened tail for balance, like an underwater float, allowing it to preserve energy while searching for prey," says Dr Qing-Hua Shang from the Chinese Academy of Sciences, in Beijing.The scientists have named the new species Brevicaudosaurus jiyangshanensis, from the Latin 'brevi' for 'short,' 'caudo' for 'tail,' and the Greek 'sauros' for 'lizard.' The most complete skeleton of the two was found in Jiyangshan quarry, giving the specimen its species name. It's just under 60cm long.The skeleton gives further clues to its lifestyle. The forelimbs are more strongly developed than the hind limbs, suggesting they played a role in helping the reptile to swim. However, the bones in the front feet are short compared to other species, limiting the power with which it could pull through the water. Most of its bones, including the vertebrae and ribs, are thick and dense, further contributing to the stocky, stout appearance of the reptile, and limiting its ability to swim quickly but increasing stability underwater.However, thick, high-mass bones act as ballast. What the reptile lost in speed, it gained in stability. Dense bones, known as pachyostosis, may have made it neutrally buoyant in shallow water. Together with the flat tail, this would have helped the predator to float motionless underwater, requiring little energy to stay horizontal. Neutral buoyancy should also have enabled it to walk on the seabed searching for slow-moving prey.Highly dense ribs may also suggest the reptile had large lungs. As suggested by the lack of firm support of the body weight, nothosaurs were oceanic nut they needed to come to the water surface for oxygen. They have nostrils on the snout through which they breathed. Large lungs would have increased the time the species could spend under water.The new species features a bar-shaped bone in the middle ear called the stapes, used for sound transmission. The stapes was generally lost in other nothosaurs or marine reptiles during preservation. Scientists had predicted that if a stapes was found in a nothosaur, it would be thin and slender like in other species of this branch of the reptilian family tree. However, in B. jiyangshanensis it is thick and elongate, suggesting it had good hearing underwater."Perhaps this small, slow-swimming marine reptile had to be vigilante for large predators as it floated in the shallows, as well as being a predator itself," says co-author Dr. Xiao-Chun Wu from the Canadian Museum of Nature.
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Animals
| 2,020 |
October 28, 2020
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https://www.sciencedaily.com/releases/2020/10/201028143107.htm
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Understanding long-term trends of stressors on koala populations
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Analysis of three decades of koala rescue data provides new insights into long-term patterns of stressors that impact koala populations in the Australian state of New South Wales. Renae Charalambous and Edward Narayan of Western Sydney University and The University of Queensland present these findings in the open-access journal
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Koala populations are declining across Australia, and the species is vulnerable to extinction. This decline has been linked to bushfires and habitat disturbance caused by human activities, such as land clearing for development. However, long-term trends of such stressors and their impact have been unclear.To better understand these long-term patterns, Charalambous and Narayan analyzed data from three wildlife rescue groups in New South Wales. The data cover a period from 1989 through 2018 and include 12,543 koala sightings and instances in which a koala was admitted for clinical care.Analysis of the data revealed that the most common reason a koala was recorded as a sighting or admitted for clinical care was disease -- most often signs of chlamydia. Most koalas that were sighted or admitted for clinical care were released. Incidents of disease increased over the course of the study period, while incidents of release dropped and incidents of euthanasia rose. The regional area with the highest number of koalas found was Lismore, which has a high level of human population growth associated with deforestation of koala habitat.The researchers conclude that their data indicates a significant impact of human population growth on koala populations through a variety of stressors, including habitat disturbance, vehicle collisions, and dog attacks. Furthermore, stress to the koala immune system resulting from bushfires and human disturbance of koala habitat may explain the prevalence of disease. Creation of sustainable connectivity between land use for agriculture and native wildlife conservation is of paramount importance at the local and national level.These findings could help inform efforts to address koala population decline through such actions as bushfire control, sustainable agricultural practices, environmental planning, and governmental policy.The authors add: "Australia's national wildlife icon, the Koala currently faces the brink of extinction crisis due to environmental trauma and diseases. We present decadal periods of evidence of significant stress and mortality risks of wild koala populations across the major hotspots in South-eastern Australia."
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Animals
| 2,020 |
October 28, 2020
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https://www.sciencedaily.com/releases/2020/10/201028124542.htm
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Giant lizards learnt to fly over millions of years
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Pterodactyls and other related winged reptiles that lived alongside the dinosaurs steadily improved their ability to fly to become the deadly masters of the sky over the course of millions of years.
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A new study published in the journal Scientists from the Universities of Reading, Lincoln and Bristol carried out the most detailed study yet into how animals evolve to become better suited to their environments over time. They combined fossil records with a new model of flight based on today's living birds to measure their flight efficiency and fill in the gaps in our knowledge of their evolutionary story.This allowed the scientists to track the gradual evolution of pterosaurs and demonstrate that they became twice as good at flying over the course of their history. It also showed that their evolution was caused by consistent small improvements over a long period, rather than sudden evolutionary bursts as had been previously suggested.Professor Chris Venditti, an evolutionary biologist at the University of Reading and lead author of the study, funded by the Leverhulme Trust, said: "Pterosaurs were a diverse group of winged lizards, with some the size of sparrows and others with the wingspan of a light aircraft. Fans of the movie Jurassic World will have seen a dramatisation of just how huge and lethal these creatures would have been. Their diet consisted mostly of other animals, from insects to smaller dinosaurs."Despite their eventual prowess in the air being well-known, the question of whether pterosaurs got better at flying and whether this gave them an advantage over their ancestors has puzzled scientists for decades. There are many examples of how natural selection works on relatively short time scales, but until now it has been very difficult to demonstrate whether plants or animals adapt to become more efficient over a long period."Our new method has allowed us to study long-term evolution in a completely new way, and answer this question at last by comparing the creatures at different stages of their evolutionary sequence over many millions of years."Pterosaurs evolved from land-based animals and first emerged as flyers in the Early Triassic period, around 245 million years ago. The first fossils are from 25 million years later.The scientists monitored changes to pterosaur flight efficiency by using fossils to measure their wingspan and body size at different stages. Their new model based on living birds was applied to the data for 75 pterosaur species, which showed that pterosaurs gradually got better at flying over millions of years.The models showed that pterosaurs adapted their body shape and size to use 50% less energy when flying over their 150 million-year history. They showed that the creatures increased in mass by 10 times, some to eventually weigh more than 300kg.The new method also revealed that one group of pterosaurs -- azhdarchoids -- was an exception to the rule. Scientists have disagreed over how well these animals flew, but the new study showed that they did not get any better throughout their existence.The enlarged size of azhdarchoids appeared to provide their survival advantage instead, with one animal -- Quetzlcoatlus -- growing to the height of a giraffe.Dr Joanna Baker, evolutionary biologist and co-author at the University of Reading said: "This is unique evidence that although these animals were competent fliers, they probably spent much of their time on the ground. Highly efficient flight probably didn't offer them much of an advantage, and our finding that they had smaller wings for their body size is in line with fossil evidence for their reduced reliance on flight."Professor Stuart Humphries, biophysicist and author from the University of Lincoln said: "One of the few things that haven't changed over the last 300 million years are the laws of physics, so it has been great to use those laws to understand the evolution of flight in these amazing animals."Professor Mike Benton at the University of Bristol said, "Until recently, paleontologists could describe the anatomy of creatures based on their fossils and work out their functions. It's really exciting now to be able to calculate the operational efficiency of extinct animals, and then to compare them through their evolution to see how efficiency has changed. We don't just have to look at the fossils with amazement, but can really get to grips with what they tell us."
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October 28, 2020
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https://www.sciencedaily.com/releases/2020/10/201028124515.htm
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Cracking the secrets of dinosaur eggshells
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Since the famous discovery of dinosaur eggs in the Gobi Desert in the early 1920s, the fossilized remains have captured the imaginations of paleontologists and the public, alike. Although dinosaur eggs have now been found on every continent, it's not always clear to scientists which species laid them. Now, researchers reporting in
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Because many dinosaur eggs are similar in size and shape, it can be difficult to determine what type of dinosaur laid them. Clues can come from fossilized embryos (which are rare), hatchlings in the same nest or nearby adult remains. Scientists also have identified microscopic features of eggshells that differ among groups of dinosaurs. In addition, researchers have studied the elemental composition of fossil eggshells to learn more about the paleoenvironment and conditions that led to the eggs' fossilization. Abel Moreno and colleagues wanted to compare the microstructure and composition of five dinosaur eggshells from nests in the El Gallo Formation of Baja California, Mexico. Based on the eggs' shapes and sizes and the fossil record of the area, the researchers had concluded that three of the eggs were laid by ornithopods (bipedal herbivores) of the hadrosaur family (duck-billed dinosaurs) and one by a theropod (bipedal carnivores) of the troodontidae family (small, bird-like dinosaurs). The remaining sample was too damaged to classify by the naked eye.Using scanning electron microscopy, the team examined the external and internal surfaces and a cross-section of each eggshell. In contrast to the smooth outer surface of the theropod shell, the shells from the ornithopods and the unknown sample had nodes at different distances across the shell. Images of shell cross-sections from the ornithopods revealed that mammillary cones -- calcite crystals on the inner surface of the shell -- formed thin, elongated columns arranged in parallel, with irregular pores. In contrast, the eggshell from the theropod showed thicker, shorter cones arranged in a bilayer, with wider pores. The unknown sample more closely resembled the ornithopod eggshells, leading the researchers to hypothesize that it was probably also from the hadrosaur family. In addition, the researchers conducted an elemental composition analysis, which they say is the first such analysis on dinosaur eggshells collected in Mexico. They say the findings might help reveal how the fossilization process varied among species and locales.
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Animals
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October 27, 2020
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https://www.sciencedaily.com/releases/2020/10/201027161524.htm
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Most migratory birds rely on a greening world
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A new study from the Cornell Lab of Ornithology confirms that most birds -- but not all -- synchronize their migratory movements with seasonal changes in vegetation greenness. This is the first study of its kind to cover the Western Hemisphere during the year-long life cycle of North American migratory birds that feed on vegetation, seeds, nectar, insects, or meat. The findings were published today in the
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"As you might expect, migration synchronization with vegetation greenness is strongest for birds that eat vegetation, seeds, or both, during spring and autumn migration, but especially during spring," says lead author Frank La Sorte at the Cornell Lab. "You could say they follow the 'green wave' north in the spring and then follow it in reverse during the fall, keeping pace with a wave that is retreating ahead of the North American winter."The "green wave" of maturing and dying vegetation is plainly visible in this animation based on data from the MODIS imaging sensors onboard the Terra and Aqua satellites. Vegetation greenness in Central and South America remains relatively stable except in the eastern portion of the continent. Animation by Frank La Sorte, Cornell Lab of Ornithology.But the pattern does not hold for carnivores, such as hawks and eagles, in the West during either migration period. The evidence is also weak for synchronization among insect-eating birds during spring migration in eastern and central portions of the United States. Birds that rely on nectar -- hummingbirds primarily -- also showed looser ties to vegetation greenness in the West. The reason for the lack of synchronization for insect-eating birds in the East is a massive geographical barrier to migration: the Gulf of Mexico. Birds wintering in Central and South America cannot detect vegetation changes on the U.S. side of the Gulf in spring and vice versa in the fall.Scientists used data from satellites to estimate the greenness of vegetation year round and cross-referenced that data with eBird observations for 230 North American migratory bird species from 2006 through 2018. eBird is the Lab's worldwide bird observation reporting platform. So why does all this matter? Climate change.Vegetation green-up in the spring is controlled by changes in temperature and precipitation; die-back of vegetation in the autumn is controlled by temperature and hours of daylight -- all factors important in timing of migrations."Our findings emphasize the need to better understand the environmental cues that regulate migratory behavior and the implications for migratory birds if these cues change," La Sorte says. "Unchecked climate change means it's more likely that there will be a mismatch -- migratory birds during stopover or when arriving on their breeding or wintering grounds could miss the peak food supply -- no matter what they eat."
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Animals
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October 27, 2020
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https://www.sciencedaily.com/releases/2020/10/201027133713.htm
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Antarctica yields oldest fossils of giant birds with 21-foot wingspans
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Fossils recovered from Antarctica in the 1980s represent the oldest giant members of an extinct group of birds that patrolled the southern oceans with wingspans of up to 21 feet that would dwarf the 11½-foot wingspan of today's largest bird, the wandering albatross.
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Called pelagornithids, the birds filled a niche much like that of today's albatrosses and traveled widely over Earth's oceans for at least 60 million years. Though a much smaller pelagornithid fossil dates from 62 million years ago, one of the newly described fossils -- a 50 million-year-old portion of a bird's foot -- shows that the larger pelagornithids arose just after life rebounded from the mass extinction 65 million years ago, when the relatives of birds, the dinosaurs, went extinct. A second pelagornithid fossil, part of a jaw bone, dates from about 40 million years ago."Our fossil discovery, with its estimate of a 5-to-6-meter wingspan -- nearly 20 feet -- shows that birds evolved to a truly gigantic size relatively quickly after the extinction of the dinosaurs and ruled over the oceans for millions of years," said Peter Kloess, a graduate student at the University of California, Berkeley.The last known pelagornithid is from 2.5 million years ago, a time of changing climate as Earth cooled, and the ice ages began.Kloess is the lead author of a paper describing the fossil that appears this week in the open access journal Pelagornithids are known as 'bony-toothed' birds because of the bony projections, or struts, on their jaws that resemble sharp-pointed teeth, though they are not true teeth, like those of humans and other mammals. The bony protrusions were covered by a horny material, keratin, which is like our fingernails. Called pseudoteeth, the struts helped the birds snag squid and fish from the sea as they soared for perhaps weeks at a time over much of Earth's oceans.Large flying animals have periodically appeared on Earth, starting with the pterosaurs that flapped their leathery wings during the dinosaur era and reached wingspans of 33 feet. The pelagornithids came along to claim the wingspan record in the Cenozoic, after the mass extinction, and lived until about 2.5 million years ago. Around that same time, teratorns, now extinct, ruled the skies.The birds, related to vultures, "evolved wingspans close to what we see in these bony-toothed birds (pelagornithids)," said Poust. "However, in terms of time, teratorns come in second place with their giant size, having evolved 40 million years after these pelagornithids lived. The extreme, giant size of these extinct birds is unsurpassed in ocean habitats,""The fossils that the paleontologists describe are among many collected in the mid-1980s from Seymour Island, off the northernmost tip of the Antarctic Peninsula, by teams led by UC Riverside paleontologists. These finds were subsequently moved to the UC Museum of Paleontology at UC Berkeley.Kloess stumbled across the specimens while poking around the collections as a newly arrived graduate student in 2015. He had obtained his master's degree from Cal State-Fullerton with a thesis on coastal marine birds of the Miocene era, between 17 million and 5 million years ago, that was based on specimens he found in museum collections, including those in the UCMP."I love going to collections and just finding treasures there," he said. "Somebody has called me a museum rat, and I take that as a badge of honor. I love scurrying around, finding things that people overlook."Reviewing the original notes by former UC Riverside student Judd Case, now a professor at Eastern Washington University near Spokane, Kloess realized that the fossil foot bone -- a so-called tarsometatarsus -- came from an older geological formation than originally thought. That meant that the fossil was about 50 million years old instead of 40 million years old. It is the largest specimen known for the entire extinct group of pelagornithids.The other rediscovered fossil, the middle portion of the lower jaw, has parts of its pseudoteeth preserved; they would have been up to 3 cm (1 inch) tall when the bird was alive. The approximately 12-cm (5-inch-) long preserved section of jaw came from a very large skull that would have been up to 60 cm (2 feet) long. Using measurements of the size and spacing of those teeth and analytical comparisons to other fossils of pelagornithids, the authors are able to show that this fragment came from an individual bird as big, if not bigger, than the largest known skeletons of the bony-toothed bird group.Fifty million years ago, Antarctica had a much warmer climate during the time known as the Eocene and was not the forbidding, icy continent we know today, Stidham noted. Alongside extinct land mammals, like marsupials and distant relatives of sloths and anteaters, a diversity of Antarctic birds occupied the land, sea and air.The southern oceans were the playground for early penguin species, as well as extinct relatives of living ducks, ostriches, petrels and other bird groups, many of which lived on the islands of the Antarctic Peninsula. The new research documents that these extinct, predatory, large- and giant-sized bony-toothed birds were part of the Antarctic ecosystem for over 10 million years, flying side-by-side over the heads of swimming penguins."In a lifestyle likely similar to living albatrosses, the giant extinct pelagornithids, with their very long-pointed wings, would have flown widely over the ancient open seas, which had yet to be dominated by whales and seals, in search of squid, fish and other seafood to catch with their beaks lined with sharp pseudoteeth," said Stidham. "The big ones are nearly twice the size of albatrosses, and these bony-toothed birds would have been formidable predators that evolved to be at the top of their ecosystem."Museum collections like those in the UCMP, and the people like Kloess, Poust and Stidham to mine them, are key to reconstructing these ancient habitats."Collections are vastly important, so making discoveries like this pelagornithid wouldn't have happened if we didn't have these specimens in the public trust, whether at UC Riverside or now at Berkeley," Kloess said. "The fact that they exist for researchers to look at and study has incredible value."
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October 27, 2020
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https://www.sciencedaily.com/releases/2020/10/201027105407.htm
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For vampire bats, social distancing while sick comes naturally
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New research shows that when vampire bats feel sick, they socially distance themselves from groupmates in their roost -- no public health guidance required.
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The researchers gave wild vampire bats a substance that activated their immune system and made them feel sick for several hours, and then returned the bats to their roost. A control group of bats received a placebo.Data on the behavior of these bats was transmitted to scientists by custom-made "backpack" computers that were glued to the animals' backs, recording the vampire bats' social encounters.Compared to control bats in their hollow-tree home, sick bats interacted with fewer bats, spent less time near others and were overall less interactive with individuals that were well-connected with others in the roost.Healthy bats were also less likely to associate with a sick bat, the data showed."Social distancing during the COVID-19 pandemic, when we feel fine, doesn't feel particularly normal. But when we're sick, it's common to withdraw a bit and stay in bed longer because we're exhausted. And that means we're likely to have fewer social encounters," said Simon Ripperger, co-lead author of the study and a postdoctoral researcher in evolution, ecology and organismal biology at The Ohio State University."That's the same thing we were observing in this study: In the wild, vampire bats -- which are highly social animals -- keep their distance when they're sick or living with sick groupmates. And it can be expected that they reduce the spread of disease as a result."The study was published today (Oct. 27, 2020) in the journal Ripperger works in the lab of co-lead author Gerald Carter, assistant professor of evolution, ecology and organismal biology at Ohio State. The two scientists and their co-author on this paper, University of Texas at Austin graduate student Sebastian Stockmaier, are also affiliated with the Smithsonian Tropical Research Institute in Panama.Carter and Ripperger have partnered on numerous studies of social behavior in vampire bats. Among their previous findings: Vampire bats make friends through a gradual buildup of trust, and vampire bat moms maintained social connections to their offspring even when both felt sick.For this work, the researchers captured 31 female common vampire bats living inside a hollow tree in Lamanai, Belize. They injected 16 bats with the molecule that induced the immune challenge -- but did not cause disease -- and 15 with saline, a placebo.After returning the bats to their roost, the scientists analyzed social behaviors in the colony over three days, including a "treatment period" from three to nine hours after the injections during which the researchers attributed behavior changes to the effects of treated bats feeling sick."We focused on three measures of the sick bats' behaviors: how many other bats they encountered, how much total time they spent with others, and how well-connected they were to the whole social network," Carter said.On average, compared to control bats, the sick bats associated with four fewer groupmates over the six-hour treatment period and spent 25 fewer minutes interacting per partner, and the time any two bats spent near each other was shortest if the encounter involved at least one sick bat."One reason that the sick vampire bats encountered fewer groupmates is simply because they were lethargic and moved around less," Carter said. "In captivity, we saw that sick bats also groom others less and make fewer contact calls. These simple changes in behavior can create social distance even without any cooperation or avoidance by healthy bats. We had previously studied this in the lab. Our goal here was to measure the outcomes of these sickness behaviors in a natural setting."The effects we showed here are probably common in many other animals. But it is important to remember that changes in behavior also depend on the pathogen. We did not use a real virus or bacteria, because we wanted to isolate the effect of sickness behavior. Some real diseases might make interactions more likely, not less, or they might lead to sick bats being avoided."Although the study did not document the spread of an actual disease, combining the social encounter data with known links between exposure time and pathogen transmission allows researchers to predict how sickness behavior can influence the spread of a pathogen in a social network.Clearly identifying each bat's behavior in the colony's social network was possible only because the proximity sensors -- miniaturized computers that weigh less than a penny and fall off within a week or two -- took measures every few seconds of associations involving sick or healthy bats or a combination of the two. Visualizations of the proximity sensors' recordings showed growth in the number of connections made in the colony's social network from the treatment period to 48 hours later."The proximity sensors gave us an amazing new window into how the social behavior of these bats changed from hour to hour and even minute to minute during the course of the day and night, even while they are hidden in the darkness of a hollow tree," said Ripperger, who is also a visiting scientist at the Museum of National History in Berlin, Germany.This work was supported by the German Research Foundation and a National Geographic Society Research Grant.
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October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026164418.htm
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Wildlife flock to backyards for food from people
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To see wildlife in the Triangle, sometimes you need go no further than your own backyard. A new study helps explain why some animals are sometimes more often found in suburban areas than wild ones: because people are feeding them -- sometimes accidentally -- and to a lesser degree, providing them with shelter.
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"They're using the gardens a little bit, they're using the brush piles a little bit, and they're using the water features, but feeding has the most dramatic influence on animal activity in the backyard," said Roland Kays, research associate professor at North Carolina State University and director of the Biodiversity & Earth Observation Lab at the NC Museum of Natural Resources.The study, published in "There's this idea that nature and humans don't coexist well," Kays said. "But what we've been finding is that when it comes to mammals, especially in North America, they actually do pretty well around people. You end up with high abundance. You expect there to be fewer animals, and there's actually more."Researchers wanted to know why that is. To test whether food and shelter are attracting animals, researchers set up cameras in the backyards of 58 homes near Raleigh, Durham, and outside of Chapel Hill, as well as in nearby forests in rural and urban areas nearby for comparison. The study was conducted in collaboration with scientists at the University of Montana.By analyzing the pictures they found, researchers discovered seven species -squirrels, gray and red fox, Virginia opossum, eastern cottontail rabbits, woodchucks and eastern chipmunks -- were more frequently seen in yards compared to forests. Eleven species, such as white-tailed deer, squirrels and raccoons, were more common in suburban forests compared to rural ones."This basically confirmed the urban-wildlife paradox, showing that some species are more abundant in yards," Kays said. "It's not a big surprise if you live in the suburbs -- you see the animals. It's the squirrels, raccoons, deer and opossum."Feeding animals -- mainly at birdfeeders -- had the strongest impact on the abundance of animals in a yard. Eastern gray squirrels were the most common sight at feeders. They were more common at feeders than in suburban or rural forests. Other common species at feeders were cottontail rabbits, raccoons and opossums."This supports the idea that direct human subsidies are a big part of the explanation for the urban-wildlife paradox," Kays said. "It shows that individual decisions by homeowners and private property owners can have a big impact on the wildlife in the backyard and living in the area."Predators such as coyotes and foxes were slightly more common in yards when other prey animals, such as squirrels or rabbits, were more abundant. However, the effect wasn't strong -- the researchers said it would take the number of prey to increase by 713 times to double the number of predators in the yard. They only observed one coyote and one red fox eating compost."There was some attraction to prey, but it was a pretty small effect," Kays said.Meanwhile, fences were deterrents to fox and other predators, and pets were deterrents to opossums and raccoons.Kays said the findings raise questions about what homeowners should do, and whether attracting wildlife is good or bad."You see widespread recommendations: Don't feed the bears. Where do you draw the line from small birds to squirrels, rabbits and raccoons? When does it become bad to feed the animals, even if you're doing it accidentally?" Kays said. "On one hand many people enjoy having wildlife around and they can help support a healthy local ecosystem; however, they could cause conflict with people."
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Animals
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October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026154002.htm
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Why bats excel as viral reservoirs without getting sick
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Bats act as reservoirs of numerous zoonotic viruses, including SARS-CoV, MERS CoV, Ebola virus, and -- most likely -- SARS-CoV-2, the pathogen behind the ongoing coronavirus pandemic. However, the molecular mechanisms bats deploy to tolerate pathogenic viruses has remained unclear.
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Now scientists from Duke-NUS Medical School, Singapore, have discovered novel molecular mechanisms that allow bats to tolerate zoonotic viruses without getting sick. Published this week in the The team examined three bat species -- Pteropus alecto (black fruit bat), Eonycteris spelaea (cave nectar bat), and Myotis davidii (David's myotis bat) -- and identified mechanisms that balance the activity of key proteins that play a major role in mediating immunity and inflammatory responses in mammals. These mechanisms enable bats to harbour and transmit zoonotic pathogens without setting off the detrimental consequences of immune activation.One of the mechanisms bats use is to reduce the levels of caspase-1, a protein that triggers a key inflammatory cytokine protein, interleukin-1 beta (IL-1β). Another mechanism they employ hampers the maturation of IL-1β cytokines through a finely-tuned balancing between caspase-1 and IL-1β."Suppression of overactive inflammatory responses improves longevity and prevents age-related decline in humans. Our findings may offer potential insights to the development of new therapeutic strategies that can control and treat human infectious diseases," said Professor Wang Linfa, senior and corresponding author of the study from Duke-NUS' Emerging Infectious Diseases (EID) Programme."This study exemplifies the world-class research led by our talented faculty to advance fundamental scientific knowledge. Professor Wang's research is all the more important in the context of COVID-19, by contributing to a greater understanding of how zoonotic diseases persist in nature, and potentially aiding new approaches to managing future outbreaks," said Professor Patrick Casey, Senior Vice-Dean for Research, Duke-NUS Medical School.
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Animals
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October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026114210.htm
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Surprised researchers: Number of leopards in northern China on the rise
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Most of the world's leopards are endangered and generally, the number of these shy and stunning cats is decreasing. However, according to a recent study, leopard populations in northern China are on the mend.
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Leopards are fascinating animals. In addition to being sublime hunters that will eat nearly anything and can survive in varied habitats from forests to deserts, they are able to withstand temperatures ranging from minus 40 degrees Celsius during winter to plus 40 degrees in summer.Despite their resilience, the majority of leopard species are endangered. Poaching and the clearing of forest habitat for human activities are among the reasons for their global decline.But in northern China -- and specifically upon the Loess Plateu -- something fantastic is occurring.Numbers of a leopard subspecies called the North Chinese leopard have increased according to a new study conducted by researchers from the University of Copenhagen and their colleagues in Beijing."We were quite surprised that the number of leopards has increased, because their populations are declining in many other places. We knew that there were leopards in this area, but we had no idea how many," says Bing Xie, a PhD student at UCPH's Department of Biology and one of the researchers behind the study.Together with researchers at Beijing Normal University, she covered 800 square kilometers of the Loess Plateu between 2016 and 2017.The just-completed count reports that the number of leopards increased from 88 in 2016 to 110 in 2017 -- a 25 percent increase. The researchers suspect that their numbers have continued to increase in the years since.This is the first time that an estimate has been made for the status of local population in North Chinese leopards.The reason for this spotted golden giant's rebound likely reflects the 13'th five-year plan that the Chinese government, in consultation with a range of scientific researchers, implemented in 2015 to restore biodiversity in the area."About 20 years ago, much of the Loess Plateau's forest habitat was transformed into agricultural land. Human activity scared away wild boars, toads, frogs and deer -- making it impossible for leopards to find food. Now that much of the forest has been restored, prey have returned, along with the leopards," explains Bing Xie, adding:"Many locals had no idea there were leopards in the area, so they were wildly enthused and surprised. And, it was a success for the government, which had hoped for greater biodiversity in the area. Suddenly, they could 'house' these big cats on a far greater scale than they had dreamed of."The research team deployed camera equipment to map how many leopards were in this area of northern China. But even though the footage captured more cats than expected on film, none of the researchers saw any of the big stealthy felines with their own eyes:"Leopards are extremely shy of humans and sneak about silently. That's why it's not at all uncommon to study them for 10 years without physically observing one," she explains.Even though Bing Xie has never seen leopards in the wild, she will continue to fight for their survival."That 98 percent of leopard habitat has been lost over the years makes me so sad. I have a great love for these gorgeous cats and I will continue to research on how best to protect them," she concludes.
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Animals
| 2,020 |
October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026095429.htm
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Hidden losses deep in the Amazon rainforest
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Few places on Earth are as rich in biodiversity and removed from human influence as the world's largest rainforest -- the Amazon. Scientists at Louisiana State University (LSU) have been conducting research within the pristine rainforest for decades. However, they began to notice that some of the animals, specifically birds that forage on and near the forest floor, had become very difficult to find.
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"What we think is happening is an erosion of biodiversity, a loss of some of the richness in a place where we would hope biodiversity can be maintained," said LSU School of Renewable Natural Resources Professor Philip Stouffer, who is the lead author of a new study published today in Stouffer began leading field research deep within the Amazon rainforest, north of Manaus, Brazil, when he was a post-doctoral researcher with the Smithsonian in 1991. With support from the National Science Foundation, he continued to oversee bird monitoring at the Biological Dynamics of Forest Fragments Project until 2016. However, around 2008, he and his graduate students noticed that they could seldom find some bird species that they had observed in previous years.Stouffer and his students devised a research plan to collect new data that would be directly comparable to historical samples from the early 1980s. LSU graduate students Vitek Jirinec and Cameron Rutt collaborated with Stouffer to synthesize the results, aided by the computational modeling expertise from co-author LSU Department of Oceanography & Coastal Sciences Assistant Professor Stephen Midway. The team analyzed the vast dataset that spanned more than 35 years and covered 55 sites to investigate what Stouffer and his graduate students had observed in the field."It's a very robust dataset from a variety of places collected over many years. It's not just some fluke. It looks like there's a real pattern and it looks like it could be linked to things we know are happening with global climate change that are affecting even this pristine place," Midway said.This downward trend signals a shifting baseline that could have gone undetected."Our nostalgia was correct -- certain birds are much less common than they used to be," Stouffer said. "If animal patterns are changing in the absence of landscape change, it signals a sobering warning that simply preserving forests will not maintain rainforest biodiversity."In general, the birds that have experienced the most dramatic declines live on or near the forest floor where they forage on arthropods, mostly insects. However, there is some variation among species winners and losers in the rainforest.For example, the Wing-banded Antbird , or Myrmornis torquata, is one of the species that has declined since the 1980s. It is also one of the species that forages insects on the forest floor by searching under leaves and other debris. Also declining is the Musician Wren , or Cyphorinus arada, a seldom-seen bird with one of the iconic voices of the Amazon.Conversely, the White-plumed Antbird , or Pithys albifrons, has not declined and remains common. Its foraging strategy may be the key to its resilience. The White-plumed Antbird follows swarms of marauding ants that churn up other insects hidden on the forest floor. The antbird jockeys for an advantageous position ahead of the ant swarm and preys upon the fleeing insects. The White-plumed Antbird is not tied to one location in the rainforest. It travels and eats a variety of prey surfaced by the swarms of ants.The scientists also found that frugivores, or birds that also eat fruit, are increasing in abundance. This suggests that omnivorous birds with more flexible diets can adjust to changing environmental conditions.More research is needed to better understand the hidden losses and shifting baseline that are happening in the Amazon rainforest and other parts of the planet."The idea that things are changing, even in the most pristine parts of our planet yet we don't even know it, illustrates the need for us to pay more attention," Stouffer said.
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Animals
| 2,020 |
October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026095421.htm
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Discovery adds new species a lab's ghoulish insect menagerie
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A horrifying insect soap opera with vampires, mummies and infant-eating parasites is playing out on the stems and leaves of live oak trees every day, and evolutionary biologist Scott Egan found the latest character -- a new wasp species that may be a parasite of a parasite -- within walking distance of his Rice University lab.
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Egan, an associate professor of biosciences at Rice, studies gall wasps, tiny insects that cast a biochemical spell on live oaks. When gall wasps lay their eggs on oak leaves or stems, they chemically program the tree to unwittingly produce a tumor-like growth, or gall, which first shelters the egg and then feeds the larval wasp that hatches from it.Egan describes the wasps as "ecosystem engineers," because their galls are attractive morsels that harbor a supporting cast of opportunistic ne'er-do-wells, thieves and killers. It's a great setting to study how competition for resources drives evolution, and Egan and his students have spent more than a decade documenting the eerie, interspecies who's-eating-who drama.The latest species they discovered at Rice, Allorhogas gallifolia (al-UHROH'-guhs GAHL'-ihf-ohl-eeuh), is one of four new wasp species from the genus Allorhogas that Egan and collaborators Ernesto Samaca-Saenz and Alejandro Zaldivar-Riveron at the National Autonomous University of Mexico (UNAM) in Mexico City described in a study this month in "They lay their egg in another wasp's gall," Egan said of A. gallifolia, which his group first hatched in 2014. "They're using the gall as a resource, and we're still not certain how, but I think they're attacking herbivorous caterpillars that are feeding on the gall tissue, and the wasp larva are eating those caterpillars after they hatch."He said more than 50 species of Allorhogas have been found in Central America and Mexico, but only two species were previously documented in the United States, one at the University of Maryland campus in 1912 and another some years later in Arizona.The A. gallifolia found at Rice was collected as part of an effort to describe the community of natural enemies for one species of gall wasp, Belonocnema treatae (behl-uh-NAHK'-nee-muh TREE'-tee). In that study and others like it that Egan's lab has published for other gall species, thousands of galls are collected across the southeastern United States, and everything that emerges from the galls is studied and cataloged. Egan describes the operation, which runs almost 365 days per year, as a "factory of discovery," and A. gallifolia was one of many mysterious specimens it has produced."It did not match any of the previously described species, so we documented that in our 2016 paper and raised the hypothesis that this might be a new species," Egan said. "A year or two went by and lead author Ernesto Samaca-Saenz contacted us and offered to collaborate on determining if this lineage was, in fact, a new species."Samaca-Saenz is a graduate student in the UNAM lab of Zaldivar-Riveron, an expert in Allorhogas and similar predatory wasps, which can be used by farmers as biological controls for crop pests. By the time Samaca-Saenz reached out about the 2016 paper, Egan's lab had collected a number of other undescribed specimens that they also suspected were new species of Allorhogas. The email kicked off a close collaboration that has taken Rice researchers on a number of trips to Mexico to conduct field work and science outreach in remote village schools.While the jury is still out on exactly how A. gallifolia interacts with other species on the galls of B. treatae, Egan said he, Samaca-Saenz and Zaldivar-Riveron have discussed a number of hypotheses."They think it could be phytophagous, meaning it's actually just eating plant material, or that it could be a gallmaker itself," Egan said. "But I'm convinced that these guys are predators of caterpillars that live inside the Belonocnema galls and eat the gall plant material. I think the larval wasp eats the caterpillar and then emerges out of the side of the gall."Egan said it will take more research to determine whether that hypothesis is true. If it is, it would be "a whole new way of life that would be unknown to this entire genus." But it would not be the first -- or the creepiest -- interaction between species that Egan and his colleagues have found.Take 2018's discovery, for example, that the parasitic vine Cassytha filiformis (kuh-SIHTH'-uh FIHL'-ih-form-ihs), commonly known as the love vine, targets B. treatae galls and sucks so many nutrients out of them that it mummifies the larval wasps inside. That marked the first observation of a parasitic plant attacking a gall-forming wasp, but it could not match the ghoulish weirdness of the crypt-keeper wasp they discovered in 2017.Euderus set (yoo-DEHR'-uhs SEHT') is so diabolical that it was named for Set, the Egyptian god who trapped, murdered and dismembered his brother in a crypt. E. set -- which Egan discovered on a family vacation in Florida and later found on a tree in his front yard -- lays its egg inside the gall of the Bassettia pallida (buh-SEHT'-eeuh PAL'-ih-duh) wasp. Both eggs hatch and the larvae live side by side, maturing inside the gall. When the pair are large enough to emerge as adults, E. set manipulates its step-sibling into trying to escape before its emergence hole is finished. When B. pallida's head gets stuck in the undersized hole, E. set begins eating. Starting from the tail, it devours a tunnel through its roommate, emerging through the head to take its place in the world outside.There are more than 1,400 known species of gall-forming wasps, and Egan said he believes there are many more species waiting to be discovered in their plant/bug-eat-bug-eat-plant corner of the world."We've focused on the gall former Belonocnema a lot, and that's where we initially found this first Allorhogas," he said. "When we reared out that entire community and tried to key out each of the members, A. gallifolia was one of those things where we could not narrow it down to a species. Nothing fit the description."Twenty-five percent of all the things we reared out of Belonocnema fit that same type of uncertainty," Egan said. "We can't find anything that's ever been described like them before. Some of those, including one I have on my desk right now, are also mostly likely new species. Considering there are 90 oak species in the United States, and I have studied only three of them, this is the tip of the biodiversity iceberg."The research was supported by the UNAM Directorate General for Academic Personnel Affairs (IN201119) and the UNAM General Directorate of Computing and Information and Communication Technologies (LANCADUNAM-DGTIC-339).
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Animals
| 2,020 |
October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026095414.htm
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DNA sleuths target ivory poachers
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Professor Adrian Linacre at Flinders University is part of a team that focuses on developing forensic DNA technology to thwart a thriving global black market in exotic animals -- and the significance of this new test working so effectively on such a difficult substance as ivory is especially significant, showing the power and accuracy of this investigation technique.
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Ivory, which is essentially a form of tooth structure, has only tiny amounts of DNA contained within it, yet Professor Linacre says the new test procedure can work with only a tiny amount of connected DNA to return results of perfect accuracy.Elephant populations have been greatly reduced, mainly due to illegal poaching for their ivory. While the trade in elephant products is protected by national laws and CITES agreements to prevent further population declines, ivory poaching and illegal trade in ivory persists. For instance, in Thailand, it is illegal to trade ivory from African elephants; however, the law allows possession of ivory from Asian elephants if permission has been obtained from the authorities. It has been difficult to determine the necessary differences by tests alone."This means the enforcement of legislation needs to classify the legal status of seized ivory products," explains Professor Linacre. "Many DNA-based techniques have been previously reported for this purpose, although these have a limit of detection not suitable for extremely degraded samples. Now, this new technique has made a great leap forward."Historically, the tiny amounts of DNA contained in tusks has made tracking the origins of ivory goods very difficult -- and why much of the poached ivory is shipped to Asia and swiftly broken down into tiny pieces, primarily for jewellery and trinkets that can be easily resold and does not allow easy or accurate DNA tracing.However, the new process can confirm the legal or illegal status of seized ivory samples, even where it is assumed that the DNA will be highly degraded.The results of the testing -- "Discrimination of highly degraded, aged Asian and African elephant ivory using denaturing gradient gel electrophoresis (DGGE)," by Nitchakamon Suwanchatree, Phuvadol Thanakiatkrai, Adrian Linacre and Thitika Kitpipit -- have been published in the In these tests, DNA from aged ivory was tested for reproducibility, specificity, and, importantly, sensitivity. Blind testing of 304 samples resulted in 100% identification accuracy. It also resulted in correct assignment in the legal status of 227 highly degraded, aged ivories within the test cohort, thus underlining the high sensitivity of the process.The result of these successful tests will have international implications for the illegal trafficking and poaching of ivory, says Professor Linacre."This research output -- which is part of our continuing analysis of forensic DNA technology to accurately analyse smaller amount of DNA -- will be beneficial to help analyse ivory casework samples in wildlife forensic laboratories, and ultimately help to identify ivory poaching hotspots."
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Animals
| 2,020 |
October 26, 2020
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https://www.sciencedaily.com/releases/2020/10/201026081447.htm
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Research provides a new understanding of how a model insect species sees color
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Through an effort to characterize the color receptors in the eyes of the fruit fly
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"The fruit fly has been, and continues to be, critical in helping scientists understand genetics, neuroscience, cancer and other areas of study across the sciences," said Camilla Sharkey, a post-doctoral researcher in the College of Biological Sciences' Wardill Lab. "Furthering our understanding of how the eye of the fruit fly detects different wavelengths of light will aid scientists in their research around color reception and neural processing."The research, led by U of M Assistant Professor Trevor Wardill, is published in The study found:Researchers discovered this by reducing carotenoids in the diets of the flies with red eyes and by testing flies with reduced eye pigmentation. While fly species with black eyes, such as house flies, are able to better isolate the long-wavelength light for each pixel of their vision, flies with red eyes, such as fruit flies, likely suffer from a degraded visual image."The carotenoid filter, which absorbs light on the blue and violet light spectrum, also has a secondary effect," said Sharkey. "It sharpens ultraviolet light photoreceptors, providing the flies better light wavelength discrimination, and -- as a result -- better color vision."
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Animals
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October 23, 2020
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https://www.sciencedaily.com/releases/2020/10/201023123115.htm
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Endangered vaquita remain genetically healthy even in low numbers
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The critically endangered vaquita has survived in low numbers in its native Gulf of California for hundreds of thousands of years, a new genetic analysis has found. The study found little sign of inbreeding or other risks often associated with small populations.
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Gillnet fisheries have entangled and killed many vaquitas in recent years and scientists believe that fewer than 20 of the small porpoises survive today. The new analysis demonstrates that the species' small numbers do not doom it to extinction, however. Vaquitas have long survived and even thrived without falling into an "extinction vortex," the new study showed. That's a scenario in which their limited genetic diversity makes it impossible to recover."The species, even now, is probably perfectly capable of surviving," said Phil Morin, research geneticist at NOAA Fisheries' Southwest Fisheries Science Center and lead author of the new study published this week in An increasing number of species in addition to the vaquita have maintained small but stable populations for long periods without suffering from inbreeding depression. Other species include the narwhal, mountain gorilla, and native foxes in California's Channel Islands. Long periods of small population sizes may have given them time to purge harmful mutations that might otherwise jeopardize the health of their populations."It's appearing to be more common than we thought that species can do just fine at low numbers over long periods," said Morin, who credited the vaquita findings to genetic experts around the world who contributed to the research.The idea that vaquitas could sustain themselves in low numbers is not new. Some scientists suspected that more than 20 years ago. Now advanced genetic tools that have emerged with the rapidly increasing power of new computer technology helped them prove the point."They've survived like this for at least 250,000 years," said Barbara Taylor, research scientist at the Southwest Fisheries Science Center. "Knowing that gives us a lot more confidence that, in the immediate future, genetic issues are the least of our concerns."The new analysis examined living tissue from a vaquita captured as part of a last-ditch international 2017 effort to save the fast-disappearing species. The female vaquita tragically died, but its living cells revealed the most complete and high-quality genome sequence of any dolphin, porpoise, or whale to date, generated in collaboration with the Vertebrate Genomes Project. Only in recent years have advances in sequencing technologies and high-powered computers made such detailed reconstruction possible.While the vaquita genome is not diverse, the animals are healthy. The most recent field effort in fall 2019 spotted about nine individuals, including three calves, within their core habitat. The robust calves suggest that inbreeding depression is not harming the health of these last vaquita. "These examples and others indicate that, contrary to the paradigm of an 'extinction vortex' that may doom species with low diversity, some species have persisted with low genomic diversity and small population size," scientists wrote in the new study.The genetic data suggest that the vaquita's isolated habitat in the far northern Gulf of California has sustained roughly 5,000 vaquitas for around 250,000 years. The advent of gillnetting for fish and shrimp only a few decades ago drove vaquitas towards extinction, as they are incidentally caught in the nets.More recently, Illegal gillnetting for totoaba, a fish about the same size and found in the same habitat as the vaquita, has compounded the losses. The practice has caused a catastrophic decline that is estimated as cutting the remaining population in half each year."Small numbers do not necessarily mean the end of a species, if they have the protection they need," Taylor said. "In conservation biology, we're always looking for risk. We shouldn't be so pessimistic. The sight of those three healthy calves in the water with their survivor mothers should inspire the protection they need to truly recover."
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October 22, 2020
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https://www.sciencedaily.com/releases/2020/10/201022170233.htm
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DNA in fringe-lipped bat feces reveals unexpected eating habits
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Feces is full of secrets. For scientists, digging into feces provides insights into animal diets and is particularly useful for understanding nocturnal or rare species. When animals eat, prey DNA travels all the way through animal digestive tracts and comes out again. Feces contains very precise information about the prey species consumed. At the Smithsonian Tropical Research Institute (STRI), a team explored the eating habits of the fringe-lipped bat (Trachops cirrhosus) by examining its stool.
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Bats hunt at night. This makes it challenging to observe their foraging behavior in nature. Analyzing DNA traces in bat guano offers a more specific way to explore how bats feed in the wild and to study how bat behavior changes depending on their eating habits."Because bats forage at night, and in the dense forest, you can't observe what they are eating the way you can with a diurnal bird or mammal," said Patricia Jones, former STRI fellow, assistant professor of biology at Bowdoin College and main author of the study. "It feels so momentous, therefore, to have a glimpse into the diet of this species that we thought we knew so much about, to discover they are eating prey we had no idea were part of their diet."The fringe-lipped bat, also known as the frog-eating bat, is well adjusted to hunting frogs. The bats' hearing is adapted to their low-frequency mating calls, and their salivary glands may neutralize the toxins in the skin of poisonous prey. Fringed-lipped bats also feed on insects, small reptiles or birds and other bats. Researchers knew that these bats often find their prey by eavesdropping on mating calls, but it was unknown if they could find prey that was silent.As expected, most of the DNA recovered from the feces samples in the study belonged to frog species and plenty of lizards, but researchers also found evidence that the bats were eating other bats and even a hummingbird. In additional experiments, wild-caught fringe-lipped bats exposed to recordings of prey sounds and stationary prey models were able to detect silent, motionless prey, as well as prey that made sounds. This led researchers to conclude that the fringe-lipped bat is more capable of locating prey by echolocation than previously thought."This is interesting because we didn't know that these bats were able to detect silent, still prey," said May Dixon, STRI fellow, doctoral student at the University of Texas at Austin and co-author of the study. "Detecting silent, still prey in the cluttered jungle is thought to be a really hard task for echolocation. This is because when the bats echolocate in the jungle, the echoes of all the leaves and branches bounce back along with the echoes of their prey, and they 'mask' the prey."These results may offer a new line of research on the sensory abilities and foraging ecology of T. cirrhosus. It also adds to a growing body of work that suggests that, in the tropics, bats may be important nocturnal predators on sleeping animals like birds. The team also found unexpected frog species among its common prey."We found T. cirrhosus were often eating frogs in the genus Pristimantis," Jones said. "I think this will open new avenues of research with T. cirrhosus, because Pristimantis call from the canopy and their calls are hard to localize, so if T. cirrhosus are consuming them it means that they are foraging differently than we understood before."Going forward, this novel combination of dietary DNA analysis with behavioral experiments may be used by other ecologists interested in the foraging behaviors of a wide range of animal species."It's really exciting to see the doors that open when animal behavior is combined with metabarcoding," said STRI staff scientist Rachel Page. "Even though we have studied Trachops intensely for decades, we actually know very little about its behavior in the wild. It was completely surprising to see prey items show up in the diet that we never anticipated, such as frog species whose mating calls seemed to lack acoustic parameters helpful for localization and, more surprising, prey that it seems the bats must have detected by echolocation alone, like hummingbirds. This work makes us rethink the sensory mechanisms underlying this bat's foraging behavior, and it opens all kinds of new doors for future questions."
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October 22, 2020
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https://www.sciencedaily.com/releases/2020/10/201022143923.htm
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High-quality cat genome helps identify novel cause of dwarfism
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A new and improved cat genome developed by the feline research teams at the University of Missouri and Texas A&M University has already proven to be a valuable tool for feline biomedical research by helping to confirm existing gene variants and new candidate genes underlying diseases in cats. The new findings are published October 22nd in
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The 94 million furry feline friends living in the U.S. suffer from many of the same diseases as their human caretakers. However, scientists don't have the depth of genetic tools necessary to develop new tests and treatments for cats.To help correct this deficit, a team of researchers developed a new, high-quality genome sequence from an Abyssinian cat named Cinnamon, which greatly improves the ability to identify more complex DNA variants that cause diseases. They also used 54 additional cat genomes from the 99 Lives Cat Genome Project and compared them to Cinnamon's genome to identify genetic variations possibly causing disease. One of their discoveries was a gene disruption that had not previously been linked to dwarfism in humans and may in rarer cases be involved in the human form of the condition.The new high-quality cat genome, and the genetic variants it has helped uncover, demonstrate the value of this resource for discovering genetic explanations of diseases in domestic cats. In future work, the team plans to expand the use of precision genomic medicine for cats using this resource and others, which could provide veterinarians more informative genetic screening, earlier disease detection and subsequent therapeutic options that will give better outcomes with fewer side effects. In addition, wildlife conservation research and investigations into how cats came to be domesticated and split into different breeds could also benefit from the new genome.
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Animals
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October 22, 2020
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https://www.sciencedaily.com/releases/2020/10/201022112613.htm
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These two bird-sized dinosaurs evolved the ability to glide, but weren't great at it
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Despite having bat-like wings, two small dinosaurs, Yi and Ambopteryx, struggled to fly, only managing to glide clumsily between the trees where they lived, researchers report October 22 in the journal
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"Once birds got into the air, these two species were so poorly capable of being in the air that they just got squeezed out," says first author Thomas Dececchi, Assistant Professor of Biology at Mount Marty University. "Maybe you can survive a few million years underperforming, but you have predators from the top, competition from the bottom, and even some small mammals adding into that, squeezing them out until they disappeared."Yi and Ambopteryx were small animals from Late Jurassic China, living about 160 million years ago. Weighing in at less than two pounds, they are unusual examples of theropod dinosaurs, the group that gave rise to birds. Most theropods were ground-loving carnivores, but Yi and Ambopteryx were at home in the trees and lived on a diet of insects, seeds, and other plants.Curious about how these animals fly, Dececchi and his collaborators scanned fossils using laser-stimulated fluorescence (LSF), a technique that uses laser light to pick up soft-tissue details that can't be seen with standard white light. Later, the team used mathematical models to predict how they might have flown, testing many different variables like weight, wingspan, and muscle placement."They really can't do powered flight. You have to give them extremely generous assumptions in how they can flap their wings. You basically have to model them as the biggest bat, make them the lightest weight, make them flap as fast as a really fast bird, and give them muscles higher than they were likely to have had to cross that threshold," says Dececchi. "They could glide, but even their gliding wasn't great."While gliding is not an efficient form of flight, since it can only be done if the animal has already climbed to a high point, it did help Yi and Ambopteryx stay out of danger while they were still alive."If an animal needs to travel long distances for whatever reason, gliding costs a bit more energy at the start, but it's faster. It can also be used as an escape hatch. It's not a great thing to do, but sometimes it's a choice between losing a bit of energy and being eaten," says Dececchi. "Once they were put under pressure, they just lost their space. They couldn't win on the ground. They couldn't win in the air. They were done."The researchers are now looking at the muscles that powered Yi and Ambopteryx to construct an accurate image of these bizarre little creatures. "I'm used to working with the earliest birds, and we sort of have an idea of what they looked like already," Dececchi says. "To work where we're just trying to figure out the possibilities for a weird creature is kind of fun."The authors were supported by Mount Marty University and The University of Hong Kong.
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October 22, 2020
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https://www.sciencedaily.com/releases/2020/10/201022112557.htm
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Social life as a driving factor of birds' generosity
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Taking a look at generosity within the crow family reveals parallels with human evolution. Working together to raise offspring and increased tolerance towards group members contribute to the emergence of generous behavior among ravens, crows, magpies and company. Biologists found that the social life of corvids is a crucial factor for whether the birds act generously or not.
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Ravens, crows, magpies and their relatives are known for their exceptional intelligence, which allows them to solve complex problems, use tools or outsmart their conspecifics. One capability, however, that we humans value highly, seems to be missing from their behavioral repertoire: generosity. Only very few species within the crow family have so far been found to act generously in experimental paradigms, while the highly intelligent ravens, for example, have demonstrated their egoistic tendencies in multiple studies. Lisa Horn of the of the Department of Behavioral and Cognitive Biology of the University of Vienna could now demonstrate, together with Jorg Massen of Utrecht University and an international team of researchers, that the social life of corvids is a crucial factor for whether the birds benefit their group members or not."Spontaneous generosity, without immediately expecting something in return, is a cornerstone of human society whose evolutionary foundations are still not fully understood. One hypothesis postulates that raising offspring cooperatively may have promoted the emergence of a tendency to willingly benefit group members in early human groups. Another hypothesis speculates that only increased tolerance towards group members and a reduced level of aggression made such generous behavior possible. While researchers found evidence for both hypotheses when investigating other non-human primates, results from other animal taxa have so far been missing," explains lead author Lisa Horn.That is why Horn and her colleagues tested generous behavior in multiple species from the crow family. Some of the tested species raise their offspring cooperatively, while others do not. Additionally, some of the species nest in close proximity with their conspecifics, thereby demonstrating their high levels of tolerance, while other species jealously guard their territories against other members of their own species. In the experiment, the birds operated a seesaw mechanism by landing on a perch, which brought food into reach of their group members. If the birds wanted to grab the food themselves, they would have had to leave the perch and the seesaw would tilt back, thereby moving the food out of reach again. Since the birds thus could not get anything for themselves the authors argued that only truly generous birds would continue to deliver food to their group members throughout multiple experimental sessions.It became evident that this behavior was displayed most strongly by these corvid species that work together to raise their offspring cooperatively. Among male birds, the researchers also found evidence for the hypothesis that high tolerance towards conspecifics is important for the emergence of generous behavior. Males from species that commonly nest in very close proximity to each other were particularly generous. These results seem to support the hypotheses that raising offspring cooperatively and increased levels of tolerance may have promoted the emergence of generous tendencies not only in humans, but also in other animals. "What fascinates me the most is that in animals that are so different from us evolutionary mechanisms very similar to the ones in our human ancestors seem to have promoted the emergence of generous behavior," concludes Horn. More studies with different bird species, like the similarly intelligent parrots, or other animal taxa are, however, needed to further investigate these connections.
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October 21, 2020
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https://www.sciencedaily.com/releases/2020/10/201021180740.htm
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Cognitive elements of language have existed for 40 million years
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Humans are not the only beings that can identify rules in complex language-like constructions -- monkeys and great apes can do so, too, a study at the University of Zurich has shown. Researchers at the Department of Comparative Language Science of UZH used a series of experiments based on an 'artificial grammar' to conclude that this ability can be traced back to our ancient primate ancestors.
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Language is one of the most powerful tools available to humankind, as it enables us to share information, culture, views and technology. "Research into language evolution is thus crucial if we want to understand what it means to be human," says Stuart Watson, postdoctoral researcher at the Department of Comparative Language Science of the University of Zurich. Until now, however, little research has been conducted about how this unique communication system came to be.An international team led by Professor Simon Townsend at the Department of Comparative Language Science of the University of Zurich has now shed new light on the evolutionary origins of language. Their study examines one of the most important cognitive elements needed for language processing -- that is, the ability to understand the relationship between the words in a phrase, even if they are separated by other parts of the phrase, known as a "non-adjacent dependency." For example, we know that in the sentence "the dog that bit the cat ran away," it is the dog who ran away, not the cat, even though there are several other words in between the two phrases. A comparison between apes, monkeys and and humans has now shown that the ability to identify such non-adjacent dependencies is likely to have developed as far back as 40 million years ago.The researchers used a novel approach in their experiments: They invented an artificial grammar, where sequences are formed by combining different sounds rather than words. This enabled the researchers to compare the ability of three different species of primates to process non-adjacent dependencies, even though they do not share the same communication system. The experiments were carried out with common marmosets -- a monkey native to Brazil -- at the University of Zurich, chimpanzees (University of Texas) and humans (Osnabrück University).First, the researchers taught their test subjects to understand the artificial grammar in several practice sessions. The subjects learned that certain sounds were always followed by other specific sounds (e.g. sound 'B' always follows sound 'A'), even if they were sometimes separated by other acoustic signals (e.g. 'A' and 'B' are separated by 'X'). This simulates a pattern in human language, where, for example, we expect a noun (e.g. "dog") to be followed by a verb (e.g. "ran away"), regardless of any other phrasal parts in between (e.g. "that bit the cat").In the actual experiments that followed, the researchers played sound combinations that violated the previously learned rules. In these cases, the common marmosets and chimpanzees responded with an observable change of behavior; they looked at the loudspeaker emitting the sounds for about twice as long as they did towards familiar combinations of sounds. For the researchers, this was an indication of surprise in the animals caused by noticing a 'grammatical error'. The human test subjects were asked directly whether they believed the sound sequences were correct or wrong."The results show that all three species share the ability to process non-adjacent dependencies. It is therefore likely that this ability is widespread among primates," says Townsend. "This suggests that this crucial element of language already existed in our most recent common ancestors with these species." Since marmosets branched off from humanity's ancestors around 40 million years ago, this crucial cognitive skill thus developed many million years before human language evolved.
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October 21, 2020
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https://www.sciencedaily.com/releases/2020/10/201021130145.htm
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Delivering proteins to testes could someday treat male infertility
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According to the Mayo Clinic, about 15% of couples are infertile, and male infertility plays a role in over one-third of these cases. Often, problems with sperm development are to blame. Now, researchers reporting in
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Male infertility often happens because of a lack of sperm in the semen, which can result from damage to the blood-testis barrier (BTB). This barrier protects reproductive cells from harmful toxicants and drugs, and a protein called PIN1 is important for its function. Mice genetically engineered to lack PIN1 are infertile, with small testes, depleted sperm stem cells and a low sperm count. Although scientists have considered gene therapies to treat male infertility, these procedures are risky because they could cause unwanted genetic changes in reproductive cells that might be passed onto offspring. Hyun-Mo Ryoo and colleagues wanted to develop a system to deliver proteins (such as PIN1) instead of genes to the testes, but first they had to find a way to get proteins through the complex tubes of the testicles and into cells.The researchers developed a delivery system called Fibroplex, which consisted of spherical nanoparticles made of silk fibroin and a coating of lipids. They loaded PIN1 into Fibroplex, and showed that the particles appeared safe and didn't show signs of toxicity or testicular damage in mice. When the team injected the PIN1-loaded Fibroplex into the testes of young mice with PIN1 deletions, the treatment restored nearly normal PIN1 levels and sperm stem cell numbers and repaired the BTB. Treated mice had normal testicular weight and size and about 50% of the sperm count of wild-type mice. Until about 5 months after treatment, when the protein degraded, the PIN1-Fibroplex-treated mice fathered a similar number of pups as wild-type mice, whereas untreated mice with PIN1 deletions remained infertile. This is the first demonstration of direct delivery of proteins into the testis to treat male infertility, the researchers say.
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October 21, 2020
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https://www.sciencedaily.com/releases/2020/10/201021085117.htm
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Lily the barn owl reveals how birds fly in gusty winds
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Scientists from the University of Bristol and the Royal Veterinary College have discovered how birds are able to fly in gusty conditions -- findings that could inform the development of bio-inspired small-scale aircraft.
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"Birds routinely fly in high winds close to buildings and terrain -- often in gusts as fast as their flight speed. So the ability to cope with strong and sudden changes in wind is essential for their survival and to be able to do things like land safely and capture prey," said Dr Shane Windsor from the Department of Aerospace Engineering at the University of Bristol."We know birds cope amazingly well in conditions which challenge engineered air vehicles of a similar size but, until now, we didn't understand the mechanics behind it," said Dr Windsor.The study, published in In the experiment, conducted in the Structure and Motion Laboratory at the Royal Veterinary College, the team filmed Lily, a barn owl, gliding through a range of fan-generated vertical gusts, the strongest of which was as fast as her flight speed. Lily is a trained falconry bird who is a veteran of many nature documentaries, so wasn't fazed in the least by all the lights and cameras."We began with very gentle gusts in case Lily had any difficulties, but soon found that -- even at the highest gust speeds we could make -- Lily was unperturbed; she flew straight through to get the food reward being held by her trainer, Lloyd Buck," commented Professor Richard Bomphrey of the Royal Veterinary College."Lily flew through the bumpy gusts and consistently kept her head and torso amazingly stable over the trajectory, as if she was flying with a suspension system. When we analysed it, what surprised us was that the suspension-system effect wasn't just due to aerodynamics, but benefited from the mass in her wings. For reference, each of our upper limbs is about 5% of our body weight; for a bird it's about double, and they use that mass to effectively absorb the gust," said lead-author Dr Jorn Cheney from the Royal Veterinary College."Perhaps most exciting is the discovery that the very fastest part of the suspension effect is built into the mechanics of the wings, so birds don't actively need to do anything for it to work. The mechanics are very elegant. When you strike a ball at the sweetspot of a bat or racquet, your hand is not jarred because the force there cancels out. Anyone who plays a bat-and-ball sport knows how effortless this feels. A wing has a sweetspot, just like a bat. Our analysis suggests that the force of the gust acts near this sweetspot and this markedly reduces the disturbance to the body during the first fraction of a second. The process is automatic and buys just enough time for other clever stabilising processes to kick in," added Dr Jonathan Stevenson from the University of Bristol.Dr Windsor said the next step for the research, which was funded by the European Research Council (ERC), Air Force Office of Scientific Research and the Wellcome Trust, is to develop bio-inspired suspension systems for small-scale aircraft.
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October 20, 2020
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https://www.sciencedaily.com/releases/2020/10/201020131344.htm
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Newly discovered gene may give 'sea pickles' their glow
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A new study describes a bioluminescent gene that could be the reason that so-called "sea pickles," or pyrosomes, an underwater free-floating colony of thousands of tiny animals, reverberate in blue-green light. If confirmed, the finding would be the first bioluminescent gene identified from a chordate -- the group that includes all vertebrates as well as a couple types of invertebrates: sea squirts (including pyrosomes) and lancelets. The research is published today in the journal
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"We know that throughout the tree of life, there are many hundreds of organisms that can produce light and that they do it for a variety of reasons," said co-author Michael Tessler, an assistant professor at St. Francis College who conducted the research while he was a postdoctoral researcher at the American Museum of Natural History. "Our work suggests that there is a common gene shared among at least some animals that, with a few small changes, could be responsible for this bioluminescence. A baseline gene like this could help explain how many of these very different organisms, like a brittle star and the sea pickle, ended up with the same ability to glow."The idea for this study arose in 2017 when co-author David Gruber, a Museum research associate and a Presidential Professor at Baruch College, was off the coast of Brazil testing a new collecting tool outfitted to a submersible: squishy robotic hands meant to gently grab delicate sea creatures. The expedition team, which included Museum Curator John Sparks and was funded by the Dalio Family Foundation and OceanX, collected a selection of sausage-sized pyrosomes (These gelatinous colonies are made of hundreds of tiny animals called zooids -- each with a heart and a brain -- that work together to move, eat, and breathe. The name pyrosome, which in Greek translates as "fire-body," is derived from their unique bioluminescent displays, which, unlike many bioluminescent animals, can be triggered by light. While pyrosomes attracted the attention of naturalists in the 17th and 18th centuries, many of the most basic facts about their bioluminescence remain elusive."Understanding the biochemical pathway for pyrosome bioluminescence is of particular interest because as a chordate, these animals are much more closely related to vertebrates -- and to us as humans -- than many of the more traditional bioluminescent creatures that might come to mind, things like jellyfish or fireflies," Gruber said.Like other bioluminescent organisms, pyrosomes rely on a chemical reaction between a substrate (luciferin) and a gene (luciferase) to produce light. The researchers found that mixing a common type of luciferin, called coelenterazine, with The researchers discovered a gene that matches a luciferase often used in biotechnology that is found in sea pansies, a relative of jellyfish, anemones, and corals. They confirmed that the newly discovered pyrosome gene does, indeed, produce light by expressing it in a bacterial colony and adding coelenterazine."Being a part of this study felt like being a part of a century-old mystery novel as to how the pyrosome glows in the dark," said Jean Gaffney, a co-author and assistant professor at Baruch College. "I have never worked with a species that was seemingly so alien, but as a chordate is strikingly similar to us."A similar gene was recently predicted from a bioluminescent brittle star, indicating that these types of luciferases may have evolved convergently from a baseline gene."This study advances the debate about pyrosome bioluminescence," Tessler said. "We provide justification for the idea that this animal produces its own light and it might be able to do so because of a pattern of evolution that as repeated throughout the animal tree of life."
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Animals
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October 20, 2020
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https://www.sciencedaily.com/releases/2020/10/201020111327.htm
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Childlessness by circumstance
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In birds and other species alike, pairs can face considerable difficulties with reproduction. Scientists at the Max Planck Institute for Ornithology in Seewiesen have now shown in an extensive analysis of 23,000 zebra finch eggs that infertility is mainly due to males, while high embryo mortality is more a problem of the females. Inbreeding, age of the parents and conditions experienced when growing up had surprisingly little influence on reproductive failures.
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Zebra finches are small songbirds that originate from Australia. As colony-living granivores, they are easy to keep in aviaries, and they reproduce all year round under favourable conditions. However, reproduction is remarkably unsuccessful: a quarter of the eggs remain unfertilised, and in another quarter of the eggs the embryo dies early during development. Researchers at the Max Planck Institute for Ornithology in Seewiesen have therefore carried out a study to investigate the potential causes of unsuccessful reproduction.The scientists tracked the fate of more than 23,000 eggs. They measured longevity, productivity, infertility, offspring mortality and other fitness-related traits that covered most phases of reproduction for both sexes. Factors that were expected to influence reproductive failure, such as inbreeding, age of the parents and growing up under unfavourable conditions had negligible effects on the reproductive performance of the zebra finches. This suggests that individuals are remarkably robust to bad conditions and that the causes must lie elsewhere.When partners are swapped to form new pairs, it becomes clear that problems with fertility typically remain with the male, while problems with embryo mortality typically remain with the female. "Of course, for both problems the pair combination also plays a role," says Yifan Pei, a doctoral student at Seewiesen, "because the formation of a viable embryo requires genes from both the mother and the father."Although the specific causes of infertility and embryo mortality could not be identified, the researchers showed that reproductive failure has a measurable genetic basis. These results are somewhat surprising, because natural selection should favour genetic variants that optimise reproduction. However, some gene variants that are advantageous for one sex may be disadvantageous for the other. Indeed, the results also indicate that gene variants that reduce male fertility tend to have positive effects on female reproductive output -- and vice versa. This effect is known by the technical term "sexually antagonistic pleiotropy" and might explain why such genetic variants can persist in the population.Many genes influence the reproductive success of zebra finches. Despite the development of sophisticated genomic techniques, it remains difficult to identify and study all genetic components -- not to mention the interaction between those genes and the interaction between the genes and the environment in which they are expressed. "If nothing else, the results of the study have shown us where it is not worth looking," says Bart Kempenaers, director of the Department. "Seemingly obvious genetic causes for unsuccessful reproduction, such as inbreeding, contribute far less than we initially thought."Wolfgang Forstmeier, who supervised the study, adds: "Now we are concentrating our work on a somewhat mysterious chromosome that only exists in the germline (cells that form the egg and the sperm), but not in the body cells of birds. Because it is difficult to take samples from the reproductive organs of living animals, the investigation of the causes is complicated. But the chromosome is a hot candidate for the origin of the problems."
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Animals
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October 19, 2020
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https://www.sciencedaily.com/releases/2020/10/201019155920.htm
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Management of a popular game fish, the smallmouth bass
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For recreational fishing enthusiasts, the thrill of snagging their next catch comes with discovering what's hooked on the end of the line. In many freshwater streams and rivers -- across the central and eastern parts of the U.S. -- anglers are often catching a popular freshwater game fish: the smallmouth bass. Now, scientists have discovered a new level of biodiversity within that species.
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Previously, scientists identified two subspecies of smallmouth bass: the widespread Northern smallmouth bass and a much smaller subgroup called the Neosho smallmouth bass. The Neosho are native to an ecologically isolated region of the lower Midwest known as the Central Interior Highlands, which weave through southwestern Missouri, northern Arkansas and northeastern Oklahoma.To help the conservation departments manage the present diversity of this smaller subspecies of smallmouth bass, two University of Missouri researchers -- Joe Gunn and Lori Eggert -- worked with the Missouri Department of Conservation, Oklahoma State University's Department of Natural Resource Ecology and Management and the Oklahoma Cooperative Fish and Wildlife Research Unit of the U.S. Geological Survey at Oklahoma State University to collect over 800 fin samples from smallmouth bass at 43 different sites in the Central Interior Highlands. The MU researchers helped analyze the samples for genetic diversity."Management is necessary because this is a gamefish," said Eggert, a conservation biologist and professor emeritus in the Division of Biological Sciences in MU's College of Arts and Science. "Human actions have already strongly affected the species and will continue to do so. This management generally takes the form of 'stocking' to enhance opportunities for recreational anglers. If the source and subspecies of fish used in stocking particular streams is not considered, stocking events could lead to 'genetic swamping' of the local fish. In some cases, this could lead to one subspecies dominating the other in streams outside its native range. Letting 'nature take its course' is not an option."For years, Eggert has studied the ecology and evolution of animal populations, including most notably African forest elephants. She originally wanted to become a veterinarian, but her passion for conservation biology developed while in college and grew as she served as an intern in the genetics program at the Zoological Society of San Diego. There, she was able to learn about conservation efforts on behalf of species such as the Przewalski's horse of Mongolia and the giant panda in China.Eggert knows a proper understanding of the genetic diversity of animal populations is important when managing these populations."With the Neosho being a native fish to the Central Interior Highlands, this study highlights the importance of thinking about management actions when moving fish between streams," Eggert said. "In the past, it's just been 'a fish is a fish,' and hatcheries were providing fish without anyone first considering where these fish are originally coming from. It's not just 'a fish is a fish.' A fish being added to a Neosho stream should really come from a Neosho stream. We also need to look at which Neosho stream is involved, because each may be home to a genetically different population, and we don't quite know yet how important the mixing of these different genetic populations is to their overall health within an ecosystem."Gunn, a graduate student in MU's College of Arts and Science, is currently working toward a doctorate in the Division of Biological Sciences, with an emphasis in conservation biology. Since he was little, he's always loved nature, and enjoys thinking about complex concepts in ecology and evolution. He wants to use his knowledge and understanding of animal species to make a positive impact on the management and preservation of threatened species and their environments.Gunn said this study shows there is considerable diversity within the smallmouth bass family."Our methods have been used before to identify previously unknown lineages of animal populations," Gunn said. "This can be applied to species within any group, whether it's mammals, fish, reptiles or birds. There are also very interesting dynamics between different groups, and these same methods can also be used to identify genetic structures and morphological differentiation within a specific species. Here, we've found considerable diversity between the two known subspecies of smallmouth bass, the Neosho and the Northern smallmouth bass, the latter of which can be found in a larger area of the U.S."
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Animals
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October 19, 2020
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https://www.sciencedaily.com/releases/2020/10/201019082832.htm
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Tapping secrets of Aussie spider's unique silk
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An international collaboration has provided the first insights into a new type of silk produced by the very unusual Australian basket-web spider, which uses it to build a lobster pot web that protects its eggs and trap prey.
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The basket-web spider weaves a silk that is uniquely rigid and so robust that the basket-web doesn't need help from surrounding vegetation to maintain its structure."As far as we know, no other spider builds a web like this," said Professor Mark Elgar from the School of BioSciences at the University of Melbourne."This silk retains its rigidity, allowing a rather exquisite silken basket or deadly ant trap."The collaboration between the University of Melbourne and the University of Bayreuth with the Australian Nuclear Science and Technology Organisation is likely to draw a lot of interest.Entomologist William J Rainbow discovered the basket-spider in 1900 but made no mention of the nature of its silk, perhaps because he had only seen drawings of the web and imagined it to be more sack-like.The recent study, just published in "Our discovery may provide insights into the evolution of foraging webs," said Professor Elgar. "It is widely thought that silk foraging webs, including the magnificent orb-webs, evolved from the habit of producing silk to protect egg cases. Perhaps the basket-web is an extension of the protective egg case and represents a rare contemporary example of an evolutionary ancestral process."The basket-web spider is found only in Australia. Its basket is approximately 11mm in diameter and 14 mm deep and has crosslinked threads of varying diameters. The nature of the silk was revealed by the Australian Synchrotron, a national facility of the Australian Nuclear Science and Technology Organisation in south east Melbourne.Professor Thomas Scheibel from the University of Bayreuth said the rigidity of the silk appears to come from the synergistic arrangement of microfibres and submicron fibres."Nature has created a complex structure that, at first glance, resembles industrially produced composites," said Professor Scheibel who headed the research from Germany."Further investigations have, however, shown that they are chemically different components and their respective properties together result in the thread's extreme elasticity and toughness, thus creating a high degree of robustness. With today's composite materials, on the other hand, it is mainly the fibres embedded in the matrix that establish the particular properties required, such as high stability."While more work needs to be done to understand the molecular details of the silk, Professor Scheibel said there is potential interest in a new genetic material that can be produced in a scalable manner."The interesting feature is the high lateral stiffness as well as the gluing substances, which could be useful in several types of applications but it will be some time before this becomes a possibility."Professor Elgar said "More generally the basket web, and the properties of its silk, highlight the importance of continuing to investigate obscure, unfamiliar species."There is increasing recognition that solutions to many of the complex challenges and puzzles we face today can be found from biological systems."This so-called 'Bioinspiration' draws on some 3.8 billion years of natural selection honing biological forms, processes and systems. The potential insights from that diversity of life, about which we still know rather little, is staggering."
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Animals
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October 19, 2020
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https://www.sciencedaily.com/releases/2020/10/201019082912.htm
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Losing flight had huge benefits for ants
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Ants are one of the most successful groups of animals on the planet, occupying anywhere from temperate soil to tropical rainforests, desert dunes and kitchen counters. They're social insects and their team-working abilities have long since been identified as one of the key factors leading to their success. Ants are famously able to lift or drag objects many times their own weight and transport these objects back to their colony. But with previous research having focused on the social aspects of an ant colony, looking at an individual ant has been somewhat neglected.
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Now, researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) and Sorbonne University in Paris have investigated why individual worker ants are so strong by taking X-ray images and creating 3D models of their thorax -- the central unit of their bodies -- to analyze their muscles and internal skeleton. Their study, published in "Worker ants evolved from flying insects," said Professor Evan Economo, who leads OIST's Biodiversity and Biocomplexity Unit. "We've always assumed that losing flight helped to optimize their bodies for working on the ground, but we have much to learn about how this is achieved."Being able to fly might be a common dream amongst people but the reality of flight is that it puts strong constraints on the build of a body. In flying insects, the wing muscles occupy a major part of the thorax -- sometimes more than 50%. This means that other muscles, which are used to support and move the head, legs, and abdomen are constrained and squeezed up against the exoskeleton.But once the constraints of flight are removed, all that space in the thorax is open, which, the researchers surmised, would allow the remaining muscles to expand and reorganize.Previous research in this area had focused on the external structure of ants but, with the technology available at OIST, the researchers were able to gain a highly detailed picture of what was going on inside the thorax. The aim was to analyze the general features common across all ants, rather than focus on the specialization of certain species. To do this, the researchers did a detailed analysis of two distantly related ant species, including both the wingless workers and the flying queens, and confirmed their findings across a broader sample of species.They used advanced X-ray technology to scan the internal and external anatomy, like CT scans used in a hospital, but at much higher resolution. From these scans, the researchers mapped all the different muscles and modeled them in 3D. The result was a comprehensive image of the inside of the thorax. They then compared findings from these two species to a range of other ants and wingless insects.As predicted, the researchers found that loss of flight had allowed for clear-cut reorganization of the thorax. "Within the worker ant's thorax, everything is integrated beautifully in a tiny space," said the late Dr. Christian Peeters, lead author of this paper, who was a research professor at Sorbonne University. "The three muscle groups have all expanded in volume, giving the worker ants more strength and power. There has also been a change in the geometry of the neck muscles, which support and move the head. And the internal attachment of muscles has been modified."Interestingly, when looking at wingless wasps, the researchers found that these insects had responded to the loss of flight in a completely different way. Wingless wasps are solitary and consume food as they find it. On the other hand, ants are part of a colony. They hunt or scavenge for food that then needs to be carried back to the nest for the queen and younger nestmates, so it makes sense that there was a selection pressure to promote carrying ability.Ants have been studied for centuries in terms of their behavior, ecology, and genetics but, the researchers emphasized, this story of strength has, so far, been somewhat overlooked. The next step is to develop more detailed biomechanical models of how different muscle groups function, do similar research on the mandible and legs, and explore the diversity seen between ant species."We're interested in what makes an ant an ant and understanding the key innovations behind their success" explained Professor Economo. "We know that one factor is the social structure, but this individual strength is another essential factor."
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Animals
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October 19, 2020
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https://www.sciencedaily.com/releases/2020/10/201019082904.htm
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Mystery over decline in sea turtle sightings
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The number of sea turtles spotted along the coasts of the UK and Ireland has declined in recent years, researchers say.
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University of Exeter scientists studied records going back more than a century (1910-2018) and found almost 2,000 sea turtles had been sighted, stranded or captured. Recorded sightings increased dramatically in the 1980s and 1990s -- possibly due to more public interest in conservation, and better reporting schemes. Numbers have dropped since 2000, but the reasons for this are unclear."Lots of factors could affect the changing of numbers of sea turtles sighted," said Zara Botterell, of the University of Exeter and Plymouth Marine Laboratory. "Climate change, prey availability and environmental disasters such as the 2010 Deepwater Horizon oil spill could all influence turtle numbers and behaviour."However, sea turtle populations in the North Atlantic are largely stable or increasing, and the apparent decrease may represent reduced reporting rather than fewer turtles in our seas. One reason for this could be that fewer fishing boats are at sea now than in the past -- and fishers are the most likely people to see and report turtles."The most common turtles spotted off the UK and Ireland are leatherbacks -- making up 1,683 of the 1,997 sightings since 1910. Leatherbacks are thought to be the only sea turtle species that "intentionally" visits these waters, with adults arriving in summer in search of their jellyfish prey.Meanwhile, juvenile loggerheads (240 since 1910) and Kemp's ridley turtles (61) are more often spotted in winter -- likely carried on currents and finding themselves stranded in cold waters.There are seven sea turtle species in total, and the others are much rarer in UK and Irish waters. Only 11 green turtle sightings were found in the records (all from 1980 to 2016), while just one hawksbill (Cork, Ireland in 1983) and one olive ridley (Anglesey, Wales in 2016) have been recorded. The only species never recorded in UK or Irish waters is the flatback, which is only found around Northern Australia, Southern Indonesia and Southern Papua New Guinea.Most of the recorded sightings of turtles in the UK and Ireland were along western and southern coasts. Of the 1,997 turtles sighted, 143 were "bycatch" (caught accidentally) in fishing lines, nets and ropes -- and the large majority of these were released alive.The study used the TURTLE database, operated by Marine Environmental Monitoring.The research team thanked the many members of the public who have reported turtle sightings and strandings, and noted the "pivotal role" of the UK Cetacean Strandings Investigation Programme (CSIP) and Scottish Marine Animal Stranding Scheme (SMASS), funded by UK governments."We have been lucky to analyse this unique dataset that exists because Britain and Ireland are a real hotbed of engaged citizen science, where members of the public report their sightings in schemes supported by conservation charities and government bodies," said Professor Brendan Godley, who leads the Exeter Marine research group.
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Animals
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October 16, 2020
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https://www.sciencedaily.com/releases/2020/10/201016090203.htm
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Explaining teamwork in male lions
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Animal cooperation typically involves sharing crucial resources -- and the rules of sharing get complicated, especially when males are involved.
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Natural selection theory dictates that males generally compete with each other for food and mates. Thus male cooperation in the animal world is an enigma, especially among unrelated animals.In a new paper published in "In a 2017 study, we detailed the behavioural nuances of why male lions cooperate: to better protect their territories and have more access to mating opportunities than males who live alone," said study lead author Stotra Chakrabarti, a postdoctoral research associate in the Department of Fisheries, Wildlife, and Conservation Biology at the University of Minnesota. "However, a lack of genetic data from the population at this stage had prevented us from determining if such cooperation extended to relatives only, or whether non-kin were included as well."Subsequent monitoring of individual lions and collection of tissue, hair and blood samples from known individuals set the stage to find out whether the cooperating males were related or they came together by chance."Genetic analyses of the Gir lions were tricky because they have undergone two population bottlenecks that have rendered discerning kin versus non-kin quite challenging," said Vishnupriya Kolipakam, co-author and faculty at the Wildlife Institute of India..By synthesizing long-term behavioural and genetic records of known mothers, offspring and siblings, researchers were able to develop a baseline panel against which male coalition partners were compared to understand the level of relatedness between them.By observing 23 male lions belonging to 10 coalitions, Chakrabarti and co-authors could identify that males who lived in large coalitions (such as trios and quartets) were typically brothers and cousins, but more than 70 percent of pairs consisted of unrelated males.In large coalitions, sharing is costlier because resources are divided between many lions, and often low-ranking partners are excluded from opportunities to breed. Such coalitions are only possible between related animals."Forgoing mating opportunities is generally a severe evolutionary cost, unless in doing so you help related individuals," said Joseph Bump, co-author and associate professor at the University of Minnesota. "As a consequence, this evidence supports a conclusion that large male lion coalitions are feasible only when all partners are brothers and/or cousins."Large coalitions fared the best as a group, but the fitness of individual lions -- measured by the number of potential offspring sired -- was higher in pairs. Such high fitness for individual male lions in pairs allowed even unrelated individuals to team up, because pairs always fared better than single males in terms of territory and mate acquisition."The results of our study show that male coalitions prosper better than loners in established lion societies and this can have crucial implications for their conservation, especially when establishing new populations through reintroductions," said YV Jhala, principal investigator of the Gir lion project and the Dean of the Wildlife Institute of India.Though large coalitions fared better as a group, they are rare in the Gir system because so few sets of sibling lions grow to maturity. An analysis of 20 years of lion demography data indicates only 12%-13% of the observed lion coalitions in Gir are made of three or four males."This calculation of demography and the availability of kin to support cooperation is often missing from studies on animal societies, but it is of fundamental value that enhances our understanding of how optimality in group formation is constrained in the real world," Jhala said.The study revealed new details about the behavior of male lions. For example, in a rare observation, researchers determined one of the study's coalitions could be a father-son duo because they were related and had an age difference of about five years."Such an observation was only possible because we could combine field observations with genetic data, and it shows that there could be multiple pathways for coalition formation in lions," said Kolipakam.Researchers also observed that related male partners were no more likely to support each other during fights with rivals than unrelated partners."This shows that kin support is not the only reason why males cooperate with each other, but kin support makes the cooperation even more beneficial," Bump said.The study indicates that underlying mechanisms facilitating cooperation in lions can be multifaceted."We have quantified the ultimate reasons why unrelated males team up, but it would be worthwhile to investigate other aspects of male cooperation, including how their bonds are forged in the first place, how they find compatible partners, what breaks the ice between them when they first meet and how they decide who will lead and who will follow." Chakrabarti said.The study was funded by the Department of Science and Technology, India and funds provided by the Wildlife Institute of India and Gujarat Forest Department to YV Jhala.
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Animals
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October 15, 2020
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https://www.sciencedaily.com/releases/2020/10/201015173118.htm
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Supergene discovery leads to new knowledge of fire ants
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A unique study conducted by University of Georgia entomologists led to the discovery of a distinctive supergene in fire ant colonies that determines whether young queen ants will leave their birth colony to start their own new colony or if they will join one with multiple queens.
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Researchers also found that ants were more aggressive toward queens who don't possess the supergene, causing main colony workers to kill them. This critical finding opens the door to new pest control methods that may be more efficient in eradicating problematic fire ant colonies."Learning about the way fire ants behave is very important baseline information," said Ken Ross, a professor of entomology at UGA. "This information is key to helping us manage pest populations and predict what dissimilarities can happen in their environment."A supergene is a collection of neighboring genes located on a chromosome that are inherited together due to close genetic linkage. Studying these unique genes is important to understanding the potential causes for differences among the social structure of fire ants, specifically for controlling the species and building on the existing knowledge base.Researchers focused on young queen fire ants embarking on nuptial flights. They compared the supergene's impact on the fire ants' two primary types of social structures: monogyne, which is reproduction from queens that form a new nest, and pologyne, reproduction from queens that join an existing nest.Ross initially worked alongside colleagues in his lab to discover a remarkable example of genetically encoded differences in social organization within the fire ant species Solenopsis invicta. The next step was to understand how these genetic differences result in complex behavioral and physiological variations among ants from single queen colonies versus colonies with multiple queens. Compounding this knowledge helps scientists further understand patterns of development in the species, increasing alternatives to combat invasive populations.Led by a pair of UGA entomology graduate alumni, Joanie King, who earned her master's degree in 2017, and Samuel Arsenault, who earned his doctoral degree in 2020, the team developed an experimental design that utilized a collection of samples from two fire ant organs -- brain and ovarian tissues -- and the complete range of social chromosome genotypes and social forms within this fire ant species.The innovative study incorporated various scientific methods, leading to a collaboration of tools and resources throughout many areas of the institution."UGA was a very supportive environment to conduct this research," said Brendan Hunt, associate professor of entomology. "We received help preparing samples for RNA sequencing from Dr. Bob Schmitz's lab in the genetics department, performed the sequencing at the Georgia Genomics and Bioinformatics Core, and utilized computational resources from the Georgia Advanced Computing Resource Center to analyze the data."These types of student-led projects give young researchers the chance to grow in a hands-on environment with mentorship and guidance from scientists with proven track records in the field."The graduate students gained experience that helped them transition to the next stages of their careers," said Hunt. "Both have gone on to continue their studies of ant genetics."
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Animals
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October 15, 2020
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https://www.sciencedaily.com/releases/2020/10/201015134219.htm
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Monkey study suggests that they, like humans, may have 'self-domesticated'
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It's not a coincidence that dogs are cuter than wolves, or that goats at a petting zoo have shorter horns and friendlier demeanors than their wild ancestors. Scientists call this "domestication syndrome" -- the idea that breeding out aggression inadvertently leads to physical changes, including floppier ears, shorter muzzles and snouts, curlier tails, paler fur, smaller brains, and more.
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The link appears to come from certain neural crest cells, present before birth and in newborns, that have a versatility akin to stem cells. These neural crest cells can turn into a handful of different things, specifically adrenal cells -- which boost the strength of the "fight or flight" response -- as well as physical traits like larger teeth and stiffer ears.Ever since Darwin's time, some scientists have speculated that humans "self-domesticated" -- that we chose less aggressive and more helpful partners, with the result that we have shifted the trajectory of our own evolution."The evidence for this has been largely circumstantial," said Asif Ghazanfar, a professor of psychology and neuroscience. "It's really a popular and exciting idea but one that lacks direct evidence, a link between friendly behavior and other features of domestication."To see if the story could be put on a robust foundation, Ghazanfar turned to marmoset monkeys. Like humans, marmosets are extremely social and cooperative, plus they have several of the physical markers consistent with domestication, including a patch of white fur on their foreheads that is common in domesticated mammals.What does cooperation look like in a monkey? Friendly vocal exchanges, caring for each other's young, and sharing food, among other signs, said Ghazanfar.The research team showed that the size of a marmoset's white fur patch was strongly related to how frequently it produced friendly vocal responses to another. This is the first set of data to show an association between a friendly behavior and a physical domestication trait in individual animals.To show a causal link between the white patch and vocal behavior, the researchers tested infant twins in different ways. In very brief sessions, one twin got reliable vocal feedback from a simulated parent -- a computer programmed with adult calls that responded to 100% of their vocalizations -- while the other twin only heard parental responses to 10% of their sounds.These experimental sessions lasted 40 minutes, every other day, for most of the first 60 days of the monkeys' lives. For the other 23+ hours of each day, the monkeys were with their families.In previous work, Ghazanfar and his colleagues showed that the infants who received more feedback learned to speak -- or more precisely, developed their adult-sounding calls -- faster than their siblings. By also measuring the white fur patches on the developing monkeys' foreheads at the same time and for three more months, the researchers discovered that the rate of the white facial coloration development was also accelerated by increased parental vocal responses. This shows a developmental connection between facial fur coloration and vocal development -- they are both influenced by parents.That connection may be via those neural crest cells that can turn into "fight or flight" cells and that also contribute to parts of the larynx, which is necessary for producing vocalizations.Domestication in other species has also been linked to changes in vocal behavior. Foxes selected for tameness have altered their vocalizations in response to the presence of humans. Similarly, a tame Bengalese finch learns and produces a more complex song, and retains greater song plasticity in adulthood, than its wild cousins.But this is the first study linking the degree of a social trait with the size of a physical sign of domestication, in any species, said the researchers. Their findings are detailed in an article published online in the journal "If you change the rate of the marmosets' vocal development, then you change the rate of fur coloration," said Ghazanfar. "It's both a fascinating and strange set of results!"
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Animals
| 2,020 |
October 15, 2020
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https://www.sciencedaily.com/releases/2020/10/201015111719.htm
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Bats save energy by reducing energetically costly immune functions during annual migration
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Both seasonal migration and the maintenance and use of an effective immune system come with substantial metabolic costs and are responsible for high levels of oxidative stress. How do animals cope in a situation when energy is limited and both costly body functions are needed? A team of scientists led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) investigated whether and how the immune response changes between pre-migration and migration seasons in the Nathusius pipistrelle bat. They confirmed that migratory bats favour the energetically "cheaper" non-cellular (humoral) immunity during an immune challenge and selectively suppress cellular immune responses. Thereby, bats save energy much needed for their annual migration. The results are published in the scientific journal
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The team of scientists around Christian C. Voigt, head of the Department of Evolutionary Ecology of the Leibniz-IZW, and Gábor Á. Czirják, senior scientist at the Department of Wildlife Diseases of the Leibniz-IZW, assessed the activity of several branches of the immune system of the Nathusius pipistrelle bat before and during migration. The seasonal journey of a 7 g Nathusius pipistrelle is energy-intensive since they fly more than 2,000 km during their annual journeys between the Baltic countries and southern France, and the metabolic turnover during flying is an order of magnitude higher than the basal metabolic rate . "It seems likely that bats will have to trade some body functions such as the immune response against the high cost of flight during migration," Voigt says. In order to verify this conjecture and to elucidate how the immune system is configured during this pivotal time of the year, the team measured the cellular and humoral response of the innate immune system (relative neutrophil numbers and haptoglobin concentration, respectively) and the cellular response of adaptive immunity (relative lymphocyte numbers) before and during migration. They compared baseline levels of these immune parameters and studied them in response to an antigen challenge."Our results confirm significant differences between the two periods. We conclude that this species of bat pays attention to the energy requirements of the different branches of immunity when switching from pre-migratory to the migratory season," Voigt explains. Before migration the cellular response of the innate immune response was significantly higher than during migration, whereas the humoral response of the same immune branch was dominant during the migration period. "The Nathusius pipistrelle responds with a strong humoral immune response to a challenge mimicking a bacterial infection. This response is more pronounced during migration, while there is no activation of the cellular response in such a situation," adds Czirják. When the animals embark on their strenuous journeys they reduce the cellular immune response, which is more energy-demanding than the humoral response. With this strategy the Nathusius pipistrelle might save energy during migration."The open question is whether or not the focus on humoral immunity during the migration period puts bats at some risk," Voigt says. "It is possible that they are more susceptible to certain pathogens while migrating if bats cannot mount an adequate cellular immune response." These and other related questions are now the topic of further immunological research by the bat research group at the Leibniz-IZW.
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Animals
| 2,020 |
October 14, 2020
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https://www.sciencedaily.com/releases/2020/10/201014201008.htm
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Beak bone reveals pterosaur like no other
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A new species of small pterosaur -- similar in size to a turkey -- has been discovered, which is unlike any other pterosaur seen before due to its long slender toothless beak.
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The fossilised piece of beak was a surprising find and was initially assumed to be part of the fin spine of a fish, but a team of palaeontologists from the universities of Portsmouth and Bath spotted the unusual texture of the bone -- seen only in pterosaurs -- and realised it was a piece of beak.Professor David Martill of the University of Portsmouth, who co-authored the study, said: "We've never seen anything like this little pterosaur before. The bizarre shape of the beak was so unique, at first the fossils weren't recognised as a pterosaur."Careful searching of the late Cretaceous Kem Kem strata of Morocco, where this particular bone was found, revealed additional fossils of the animal, which led to the team concluding it was a new species with a long, skinny beak, like that of a Kiwi.Lead author of the project, University of Portsmouth PhD student Roy Smith, said: "Just imagine how delighted I was, while on field work in Morocco, to discover the lower jaw to match the upper jaw found by Dr Longrich of this utterly unique fossil animal."The new species, Pterosaurs are the less well-known cousins of dinosaurs. Over 100 species of these winged-reptiles are known, some as large as a fighter jet and others as small as a sparrow.Professor Martill said: "The diets and hunting strategies of pterosaurs were diverse -- they likely ate meat, fish and insects. The giant 500-pound pterosaurs probably ate whatever they wanted."Some species hunted food on the wing, others stalked their prey on the ground. Now, the fragments of this remarkable little pterosaur show a lifestyle previously unknown for pterosaurs."The scientists used a computerised tomography (CT) scan to reveal an incredible network of internal canals for nerves that helped detect the prey underground.Dr Nick Longrich, from the Milner Centre for Evolution at the University of Bath, said: "Leptostomia may actually have been a fairly common pterosaur, but it's so strange -- people have probably been finding bits of this beast for years, but we didn't know what they were until now."Long, slender beaks evolved in many modern birds. Those most similar to Leptostomia are probing birds -- like sandpipers, kiwis, curlews, ibises and hoopoes. Some of these birds forage in earth for earthworms while others forage along beaches and tidal flats, feeding on bristle worms, fiddler crabs, and small clams.Leptostomia could probably have done either, but its presence in the Cretaceous age Kem Kem strata of Africa -- representing a rich ecosystem of rivers and estuaries -- suggests it was drawn there to feed on aquatic prey."You might think of the pterosaur as imitating the strategy used successfully by modern birds, but it was the pterosaur that got there first," said Dr Longrich. "Birds just reinvented what pterosaurs had already done tens of millions of years earlier."Dr Longrich suggests the new species shows how, more than a century after pterosaurs were first discovered, there's still so much to learn about them. He said: "We're underestimating pterosaur diversity because the fossil record gives us a biased picture."Pterosaur fossils typically preserve in watery settings -- seas, lakes, and lagoons -- because water carries sediments to bury bones. Pterosaurs flying over water to hunt for fish tend to fall in and die, so they're common as fossils. Pterosaurs hunting along the margins of the water will preserve more rarely, and many from inland habitats may never preserve as fossils at all."There's a similar pattern in birds. If all we had of birds was their fossils, we'd probably think that birds were mostly aquatic things like penguins, puffins, ducks and albatrosses. Even though they're a minority of the species, their fossil record is a lot better than for land birds like hummingbirds, hawks, and ostriches."Over time, more and more species of pterosaurs with diverse lifestyles have been discovered. That trend, the new pterosaur suggests, is likely to continue.The paper was published today in
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Animals
| 2,020 |
October 14, 2020
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https://www.sciencedaily.com/releases/2020/10/201014141109.htm
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Ivory Coast without ivory? Elephant populations are declining rapidly in Côte d'Ivoire
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Recent years have witnessed a widespread and catastrophic decline in the number of forest elephants in protected areas in Côte d'Ivoire, according to a study published October 14 in the open-access journal
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In precolonial and colonial times, Côte d'Ivoire probably hosted one of the largest elephant populations in West Africa, resulting in the country's name, which translates to Ivory Coast. During the last three decades, elephant populations have sharply decreased, mainly because of forest agricultural clearing. By the early 1990s, the total number of savannah and forest elephants in the entire country was estimated to be less than 360. The most recently collected data on Côte d'Ivoire elephants are at least one decade old, and most of these studies did not follow a standardized protocol. In the new study, the authors present updated information on the distribution and conservation status of forest elephants in Côte d'Ivoire. The authors analyzed dung counts, records of human-elephant conflicts, media reports, and interview survey data obtained from 2011 to 2017.Of the 25 protected areas surveyed, elephant presence was confirmed in only four areas, where elephant density was low. More than half of the protected areas had been completely converted to farms and human settlements. Protected areas with higher levels of protection had a higher probability of hosting an elephant population. The presence of elephants inside protected areas was affected by human population size, habitat degradation, and the proportion of forest converted to cocoa plantation. According to the authors, aggressive conservation actions, including law enforcement and ranger patrolling, are needed to protect the remaining forest elephant populations.The authors add: "The large majority of the protected area of Côte d'Ivoire has lost its entire elephant populations as a consequence of the lack of conservation measures. Out of the 25 protected areas surveyed, forest elephants of Côte d'Ivoire are now confined into small populations in four protected areas."
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Animals
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October 14, 2020
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https://www.sciencedaily.com/releases/2020/10/201014114642.htm
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Seeing evolution happening before your eyes
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Animal diversity and evolution are driven by changes in how our genetic code is expressed. Specific DNA sequences called enhancers control where, when and how strongly genes are expressed during development to create the respective organism. Studying enhancers and how they result in different patterns of gene expression therefore helps us to understand more about how evolution takes place. In addition to driving the evolution of species, enhancers are also relevant to disease: mutations in enhancers are associated with over 80% of all human diseases.
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"What we see in terms of biodiversity in nature is caused, to a large degree, by changes in enhancers," explains Justin Crocker, group leader at EMBL Heidelberg. "Understanding -- and subsequently trying to predict -- evolution in the time of climate change, where many animals are under the pressure to adapt quickly to fast changing environments, is an important task."Despite broad relevance to evolution and disease, researchers still struggle to understand how enhancers are coded in our genomes and how easy it is to reprogram them, for example to prevent or treat diseases. In an attempt to learn more about enhancers, the Crocker group from EMBL Heidelberg performed an extensive study, published in "Whenever we changed a single letter of the enhancer DNA sequence, we created a significant change to the pattern of gene expression it drove," explains Timothy Fuqua, PhD student at EMBL and first author of the paper. "We also found that almost all mutations to the enhancer alter the gene expression pattern in multiple ways. For example, one mutation controls not only where the expression pattern is within the fly, but also when, and how much of the gene was expressed."These results were surprising and contradict what had previously been known about enhancers. Researchers thought that these complex gene expression patterns were created by different proteins attaching to the enhancer. A first clue that this might not be true came when Crocker and his team discovered that artificially-produced enhancers did not work as designed. Their most recent results provide support for this idea. "The results showed that developmental enhancers encode a much higher level of information than previously appreciated," Crocker says. "When we received the data, I was honestly shocked! I couldn't believe it and we repeated everything, as we assumed that there has been a mistake."Importantly, the density of information encoded within the enhancer also constrains how animals can evolve. The study also showed that each possible mutation has a certain possibility for happening. This gives scientists insights into where evolution could lead. "We can use this information to predict patterns in wild fruit flies. Something which has been incredibly difficult to do so far," Fuqua says. "Our results should encourage the community to reassess our assumption about how these regions contribute to human health."While studying enhancers is a well-established field in molecular biology, this study is unique in the sheer number of mutations having been studied. The group created more than 700 unique, randomly generated mutations within a single enhancer. "Nobody ever has studied so many enhancer variants at this level of depth before. It was as if evolution was happening before our very eyes!" highlights Fuqua. To perform so many experiments, the team built -- assisted by the Janelia Research Campus and the Advanced Light Microscopy Facility at EMBL -- a robot to handle the fly embryos used in the study, and an automated microscope pipeline to take images of each mutated line."Our study shows that what we have known about enhancers was oversimplified. It shows we have to study enhancers at much greater detail than ever before," Fuqua says. Therefore, in the next step, the team not only wants to expand the pipeline and its throughput, but also plans to study other enhancers and see if they can observe similar effects. "Can what we found be applied to other enhancers or not? We don't know yet. But we plan to find out," concludes Crocker.
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Animals
| 2,020 |
October 14, 2020
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https://www.sciencedaily.com/releases/2020/10/201014082754.htm
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Swine coronavirus replicates in human cells
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New research from the University of North Carolina at Chapel Hill suggests that a strain of coronavirus that has recently alarmed the swine industry may have the potential to spread to humans as well.
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The coronavirus strain, known as swine acute diarrhea syndrome coronavirus (SADS-CoV), emerged from bats and has infected swine herds throughout China since it was first discovered in 2016. Outbreaks of such an illness have the potential to wreak economic havoc in many countries across the globe that rely on the pork industry.The virus' potential threat to people was demonstrated in lab tests that revealed SADS-CoV efficiently replicated in human liver and gut cells, as well as airway cells. The findings were published Oct. 12 in Though it is in the same family of viruses as the betacoronavirus SARS-CoV-2, which causes the respiratory illness COVID-19 in humans, SADS-CoV is an alphacoronavirus that causes gastrointestinal illness in swine. The virus causes severe diarrhea and vomiting and has been especially deadly to young piglets.SADS-COV is also distinct from two circulating common cold alphacoronaviruses in humans, HCoV-229E and HCoV-NL63."While many investigators focus on the emergent potential of the betacoronaviruses like SARS and MERS, actually the alphacoronaviruses may prove equally prominent -- if not greater -- concerns to human health, given their potential to rapidly jump between species," said Ralph Baric, professor of epidemiology at UNC-Chapel Hill Gillings School of Global Public Health.While SADS-CoV has not been known to affect humans to-date, the COVID-19 pandemic serves as a potent reminder that many coronavirus strains found in animals have the potential to infect humans as well -- an effect known as spillover.The Baric lab worked with Caitlin Edwards, a research specialist and master of public health student at UNC-Chapel Hill, on the study which suggests humans may be susceptible to spillover of SADS-CoV.Edwards, the study's first author, tested several types of cells by infecting them with a synthetic form of SADS-CoV to understand just how high the risk of cross-species contamination could be.Evidence from the study indicates that a wide range of mammalian cells, including primary human lung and intestinal cells, are susceptible to infection. According to Edwards, SADS-CoV shows a higher rate of growth in intestinal cells found in the human gut, unlike SARS-CoV-2, which primarily infects lung cells.Cross-protective herd immunity often prevents humans from contracting many coronaviruses found in animals. However, results from the testing done by Edwards and her team suggest that humans have not yet developed such immunity to SADS-CoV."SADS-CoV is derived from bat coronaviruses called HKU2, which is a heterogenous group of viruses with a worldwide distribution," Edwards said. "It is impossible to predict if this virus, or a closely related HKU2 bat strain, could emerge and infect human populations. However, the broad host range of SADS-CoV, coupled with an ability to replicate in primary human lung and enteric cells, demonstrates potential risk for future emergence events in human and animal populations."In response to these findings, Edwards and colleagues tested the broad-spectrum antiviral remdesivir as a potential method of treatment for the infection.Working with Gilead Sciences, remdesivir was developed by the Baric Lab to combat all known coronaviruses, including SADS-CoV. It is currently being used to treat COVID-19 infections in humans, including the United States president. Preliminary results from this study show that it has robust activity against SADS-CoV, though Edwards cautions that more testing is necessary on additional cell types and in animals to confirm these findings."Promising data with remdesivir provides a potential treatment option in the case of a human spillover event," she said. "We recommend that both swine workers and the swine population be continually monitored for indications of SADS-CoV infections to prevent outbreaks and massive economic losses."SADS-CoV could also pose a threat to the U.S. economy, which was third in global pork production in 2019. In 2012, the U.S. pork industry was devastated by different swine coronavirus that emerged from China."Not surprisingly, we are currently looking for partners to investigate the potential of SADS-CoV vaccine candidates to protect swine," Baric said. "While surveillance and early separation of infected piglets from sows provide an opportunity to mitigate larger outbreaks and the potential for spillover into humans, vaccines may be key for limiting global spread and human emergence events in the future."Other members of the Department of Epidemiology involved in the study include Boyd Yount, Assistant Professor Rachel Graham, PhD; Sarah Leist, PhD; Yixuan Hou, PhD; Associate Professor Amy Sims, PhD; Jesica Swanstrom, Trevor Scobey, Michelle Cooley and Caroline Currie.
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Animals
| 2,020 |
October 13, 2020
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https://www.sciencedaily.com/releases/2020/10/201013124123.htm
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On the trail of novel infectious agents in wildlife
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The species richness of zoo and wild animals is reflected in the diversity of infectious agents they harbour. However, our knowledge is sparse and pathogen detection remains challenging. For streptococci, a bacterial family of importance to human and animal health, wildlife research has taken a step forward: A research team led by Kristin Mühldorfer from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) and Tobias Eisenberg from the Hessian State Laboratory investigated the causes of severe respiratory disease in peccaries and taxonomically characterised a novel Streptococcus species (Streptococcus catagoni sp. nov.) based on its phenotypic properties and genetic features. The results, published in the
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The family Streptococcaceae consists of bacteria inhabiting the skin and mucous membranes and includes important pathogens. Despite Streptococcus species with a broad host range infecting humans and vertebrates, the family includes bacterial species that seems to be exclusively adapted to certain hosts or habitats, such as Streptococcus castoreus of beavers, Streptococcus didelphis of certain marsupial species or Streptococcus phocae of marine mammals and fish.In the present paper the authors analysed a previously unknown Streptococcus species that was responsible over two consecutive years for severe disease in a group of Chacoan peccaries (Catagonus wagneri) kept in a zoo. Animals were mainly affected within the first year of life and showed suppurative infections of the upper and lower respiratory tract. At least five peccaries had died from the infection. The novel bacterial species has been named according to its origin as Streptococcus catagoni sp. nov."These are the first confirmed cases in Chacoan peccaries," says Dr Kristin Mühldorfer, scientist from the Leibniz-IZW. The Chacoan peccary is an endangered species that shows a continuing decline in its population size. "Unfortunately, we often do not know the impact of infectious diseases on wildlife populations and associated pathogens," says Mühldorfer. The reasons for these deficits include animal species richness, the lack of knowledge of wildlife health and restricted accessibility of wild animals in their habitats.Novel infectious agents frequently occur in zoo and wild animals but they are often not identified with established test systems and data bases, thereby increasing time and methodical requirements of laboratories considerably. MALDI-TOF mass spectrometry provides a good solution because newly created reference spectra enable rapid and reliable bacterial identifications. The data base entries of Streptococcus catagoni were generated at the Chemical and Veterinary Analysis Agency Stuttgart and are available for exchange via the MALDI-TOF MS User Platform."We are glad to have established this successful collaboration of the participating institutions which we hope will continue," say Kristin Mühldorfer and Tobias Eisenberg. The microbiologists aim to characterise uncommon bacterial agents, their occurrence in specific hosts and importance for certain wildlife species. Modern approaches to wildlife disease will help to detect pathogens and develop diagnostics to overcome current limitations and support conservation efforts.
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Animals
| 2,020 |
October 12, 2020
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https://www.sciencedaily.com/releases/2020/10/201012164219.htm
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Carnivores living near people feast on human food, threatening ecosystems
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Ecologists at the University of Wisconsin-Madison have found that carnivores living near people can get more than half of their diets from human food sources, a major lifestyle disruption that could put North America's carnivore-dominated ecosystems at risk. The researchers studied the diets of seven predator species across the Great Lakes region of the U.S. They gathered bone and fur samples for chemical analysis from areas as remote as national parks to major metropolitan regions like Albany, New York. They found that the closer carnivores lived to cities and farms, the more human food they ate.
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While evolution has shaped these species to compete for different resources, their newfound reliance on a common food source could put them in conflict with one another. That conflict could be reordering the relationship between different carnivores and between predators and prey, with an unknown but likely detrimental impact on ecosystems that evolved under significant influence of strong predators.Jon Pauli, a UW-Madison professor of forest and wildlife ecology, and his former graduate student Phil Manlick, published their findings this week in the How much human food they ate varied considerably by location. On average, more than 25 percent of the carnivores' diets came from human sources in the most human-altered habitats.It also varied by species. For instance, committed carnivores like bobcats ate a relatively small amount of human food. "But what you see is that the sort of generalist species that you might expect -- coyotes, foxes, fishers, martens -- in human-dominated landscapes, they're getting upwards of 50 percent of their diet from human foods," says Manlick, the lead author of the study who is now a postdoctoral researcher at the University of New Mexico. "That's a relatively shocking number, I think."Pauli and Manlick found that relying on human food sources increased how much carnivores overlapped one another in their competition for food. Compared to when these predators vie for distinct prey, this increased competition could lead to more conflicts between animals. Their reliance on human food could also make the carnivores vulnerable to human attacks near towns, or even change how and when they hunt traditional prey, with potentially harmful ecological consequences.The researchers studied the diets of almost 700 carnivores, including red and gray foxes, fishers, and American martens. They gathered bone and fur samples from Minnesota, Wisconsin, New York and the Upper Peninsula of Michigan with the help of state and federal researchers and citizen-science trappers. The researchers compared the carnivores' diets to the extent of human development in the region, which varied from essentially pristine wilderness to urban sprawl.Thanks to quirks in how plants incorporate carbon as they grow, a sample of bone or fur is enough to get a snapshot of an animal's diet. Different weights, or isotopes, of carbon are common in different plants -- and in the animals who ultimately eat them."Isotopes are relatively intuitive: You are what you eat," says Manlick. "If you look at humans, we look like corn."Human foods, heavy in corn and sugar, lend them distinctive carbon signatures. In contrast, the diets of prey species in the wild confer their own carbon signatures. The ratio of these two isotope fingerprints in a predator's bone can tell scientists what proportion of their diet came from human sources, either directly or from their prey that ate human food first.The geographic extent of the study and the large number of species the ecologists examined demonstrate that the trend of human food subsidies in carnivore diets is not limited to a single location or species. The ultimate outcome of such widespread disruptions remains unclear."When you change the landscape so dramatically in terms of one of the most important attributes of a species -- their food -- that has unknown consequences for the overall community structure," says Pauli. "And so I think the onus is now on us as ecologists and conservation biologists to begin to understand these novel ecosystems and begin to predict who are the winners and who are the losers."This work was supported in part by the National Science Foundation (grant DGE-1144752), the National Institute of Food and Agriculture (Hatch Projects 1006604 and 1003605), and the National Park Service.
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Animals
| 2,020 |
October 12, 2020
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https://www.sciencedaily.com/releases/2020/10/201012115958.htm
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Mosquitoes' taste for blood traced to four types of neurons
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It's one of the world's deadliest animals, and it has a taste for human blood: the mosquito.
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Mosquitoes spread diseases like malaria, dengue, and yellow fever that kill at least a half a million people each year. Now researchers are learning what humans taste like to mosquitoes, down to the individual neurons that sense blood's distinctive, delectable flavor.Female mosquitoes have a sense of taste that is specially tuned to detect a combination of at least four different substances in blood, Howard Hughes Medical Institute Investigator Leslie Vosshall's team at The Rockefeller University and colleagues report October 12, 2020, in the journal "This is definitely a technical tour de force," says neuroscientist Chris Potter of the Johns Hopkins University School of Medicine, who studies mosquito repellents. Identifying the specific taste neurons associated with blood might be something "we could use against the mosquito," he says.Vosshall and her team already knew a great deal about the insect's other finely tuned senses. In previous work, for instance, they've found that mosquitoes can detect the repellent DEET with their legs and have identified an odorant receptor that mosquitoes use to distinguish between humans and non-humans. But little is known about mosquitoes' sense of taste, despite being key to spreading illness. "If mosquitoes weren't able to detect the taste of blood, in theory they couldn't transmit disease," says Veronica Jové, an HHMI Gilliam Fellow at Rockefeller who led the work in Vosshall's laboratory.Only female mosquitoes feed on blood, which they need for their eggs to develop. That puts females in a unique position. They need to distinguish between the sweet nectar they eat for most of their meals and the blood they gorge on before laying eggs.Jové suspected that female Aedes aegypti mosquitoes, unlike males, would be able to distinguish between the two substances by taste. Indeed, in behavioral experiments she found that female mosquitoes have two feeding modes that use different mouthparts and detect different flavors. A nectar-feeding mode detects sugars and a blood-feeding mode uses a syringe-like "stylet" to pierce the skin and taste blood. Jové tricked the mosquitoes into the blood-feeding mode by offering them a mix of four compounds: glucose (a sugar), sodium chloride (salt), sodium bicarbonate (found in both blood and baking soda), and adenosine triphosphate, or ATP, a compound that provides energy to cells.Vosshall was curious, so she asked Jové to whip up an ATP solution in the lab and then took a sip. "It doesn't have a taste at all," she says. "ATP is this special mystery stuff that tastes like nothing to humans. But it's got to be incredibly exciting and rewarding for the mosquito."Just as a human has taste buds that differentiate between salty, sweet, bitter, sour, and umami flavors, a mosquito's stylet has neurons specialized to respond to particular flavors. To see these taste neurons in action, the researchers genetically modified mosquitoes with a fluorescent tag that glowed when a nerve cell was activated. Then they watched which cells in the stylet lit up in response to different meals. Only a subset were activated by blood, including both real blood and the researchers' artificial mix.So just what does human blood taste like to a mosquito? Perhaps the closest we can say is that it's a little salty and a little sweet. It's a bit like trying to describe the way a honeybee sees a flower in ultraviolet hues invisible to the human eye, or how a bat eavesdrops on sonar waves we can't hear, Vosshall says. Likewise, a female mosquito can taste things we can't. "There is nothing like this in the human experience," she says.The findings shed light on just how specially adapted the female mosquito is to find blood. Jové and Vosshall say they hope that a better understanding of mosquitoes' senses will ultimately lead to new ways to stop them from biting us and spreading disease.One possibility might sound like science fiction, Vosshall says, but there is precedent. "I just gave my dogs their monthly flea and tick medication, which is oral," she says. Perhaps something similar could eventually be done for mosquitoes -- a drug that humans could take before going to a mosquito-infested area that would interfere with mosquito's taste for blood.That idea, which boils down to making humans less delicious, raises one last question. Are some people really "tastier" to mosquitoes than others? "We're all tasty enough for a mosquito," Jové says. Once they detect blood, she says, "we don't have a sense they're very picky."
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Animals
| 2,020 |
October 9, 2020
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https://www.sciencedaily.com/releases/2020/10/201009114202.htm
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Oldest monkey fossils outside of Africa found
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Three fossils found in a lignite mine in southeastern Yunan Province, China, are about 6.4 million years old, indicate monkeys existed in Asia at the same time as apes, and are probably the ancestors of some of the modern monkeys in the area, according to an international team of researchers.
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"This is significant because they are some of the very oldest fossils of monkeys outside of Africa," said Nina G. Jablonski, Evan Pugh University Professor of Anthropology, Penn State. "It is close to or actually the ancestor of many of the living monkeys of East Asia. One of the interesting things from the perspective of paleontology is that this monkey occurs at the same place and same time as ancient apes in Asia."The researchers, who included Jablonski and long-time collaborator Xueping Ji, department of paleoanthropology, Yunnan Institute of Cultural Relics and Archaeology, Kunming, China, studied the fossils unearthed from the Shuitangba lignite mine that has yielded many fossils. They report that "The mandible and proximal femur were found in close proximity and are probably of the same individual," in a recent issue of the "The significance of the calcaneus is that it reveals the monkey was well adapted for moving nimbly and powerfully both on the ground and in the trees," said Jablonski. "This locomotor versatility no doubt contributed to the success of the species in dispersing across woodland corridors from Europe to Asia."The lower jawbone and upper portion of the leg bone indicate that the individual was female, according to the researchers. They suggest that these monkeys were probably "jacks of all trades" able to navigate in the trees and on land. The teeth indicate they could eat a wide variety of plants, fruits and flowers, while apes eat mostly fruit."The thing that is fascinating about this monkey, that we know from molecular anthropology, is that, like other colobines (Old World monkeys), it had the ability to ferment cellulose," said Jablonski. "It had a gut similar to that of a cow."These monkeys are successful because they can eat low-quality food high in cellulose and obtain sufficient energy by fermenting the food and using the subsequent fatty acids then available from the bacteria. A similar pathway is used by ruminant animals like cows, deer and goats."Monkeys and apes would have been eating fundamentally different things," said Jablonski. "Apes eat fruits, flowers, things easy to digest, while monkeys eat leaves, seeds and even more mature leaves if they have to. Because of this different digestion, they don't need to drink free water, getting all their water from vegetation."These monkeys do not have to live near bodies of water and can survive periods of dramatic climatic change."These monkeys are the same as those found in Greece during the same time period," said Jablonski. "Suggesting they spread out from a center somewhere in central Europe and they did it fairly quickly. That is impressive when you think of how long it takes for an animal to disperse tens of thousands of kilometers through forest and woodlands."While there is evidence that the species began in Eastern Europe and moved out from there, the researchers say the exact patterns are unknown, but they do know the dispersal was rapid, in evolutionary terms. During the end of the Miocene when these monkeys were moving out of Eastern Europe, apes were becoming extinct or nearly so, everywhere except in Africa and parts of Southeast Asia."The late Miocene was a period of dramatic environmental change," said Jablonski. "What we have at this site is a fascinating snapshot of the end of the Miocene -- complete with one of the last apes and one of the new order of monkeys. This is an interesting case in primate evolution because it testifies to the value of versatility and adaptability in diverse and changing environments. It shows that once a highly adaptable form sets out, it is successful and can become the ancestral stock of many other species."The National Science Foundation, Penn State and Bryn Mawr funded this research.
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Animals
| 2,020 |
October 8, 2020
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https://www.sciencedaily.com/releases/2020/10/201008142057.htm
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Study finds fungal disease of snakes in 19 states, Puerto Rico
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In a collaborative effort between scientists and personnel on military bases in 31 states in the continental U.S. and Puerto Rico, researchers surveyed for an infection caused by an emerging fungal pathogen that afflicts snakes. The effort found infected snakes on military bases in 19 states and Puerto Rico, demonstrating that the fungus is more widely distributed than was previously known. The team reports the findings in the journal
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"Ophidiomycosis -- formerly known as 'snake fungal disease' -- is an emerging infectious disease caused by the fungus Ophidiomyces ophidiicola," said Dr. Matt Allender, a professor in the veterinary diagnostic laboratory at the University of Illinois Urbana-Champaign who led the new study. "It has been documented in over 15 genera of wild and captive snakes. Infection with the pathogen causes a wide range of clinical signs in snakes, from difficulty shedding skin, to crusts and ulcers on the head and body, and even death in some cases."Allender is the director of the Wildlife Epidemiology Lab at the U. of I. and an expert on ophidiomycosis."We looked for this pathogen in samples from 657 snakes and found that 17% were infected. Our findings include the first reports of this disease in Oklahoma, Idaho and Puerto Rico," he said.The team tested swab samples taken from snakes representing 58 species. The researchers used a qPCR assay they developed, which amplifies the DNA in small samples to detect and measure the extent of infection. Biologists who collected the samples also inspected the snakes for scabs or other signs of disease. The scientists detected the pathogen in samples from 113 snakes representing 25 species including copperheads, eastern diamondback rattlesnakes, Puerto Rican boas, sidewinders and whip snakes."Adults had greater odds of being diagnosed with ophidiomycosis than younger snakes," the researchers reported. "Snakes from Georgia, Massachusetts, Pennsylvania, and Virginia all had greater odds of ophidiomycosis diagnosis, while snakes from Idaho were less likely to be diagnosed with the disease."This likely reflects a larger distribution of this disease in snakes in the eastern U.S. than previously thought, and its possible expansion from east to west, Allender said. The disease was first confirmed in 2006 in a population of timber rattlesnakes in New Hampshire.Snakes worldwide are suffering as a result of habitat loss, climate change and infectious diseases like ophidiomycosis. Their health and abundance are important to human health, as snakes control populations of small mammals that carry and amplify pathogens that also cause disease in humans such as hanatavirus and Lyme disease, Allender said.Natural lands on military bases provide an unexpected sanctuary for many threatened or endangered species, he said.Previous studies by project co-investigators with the Department of Defense have found that amphibian and reptile species living on DOD lands represent nearly two-thirds of the total native amphibian and reptile species documented in the continental U.S."Ophidiomycosis has potentially serious consequences for the success of snake conservation efforts in North America, threatening biodiversity across several habitats," Allender said.The paper "Ophidiomycosis, an emerging fungal disease of snakes: Targeted surveillance on military lands and detection in the western US and Puerto Rico" is available from the U. of I. News Bureau.
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Animals
| 2,020 |
October 8, 2020
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https://www.sciencedaily.com/releases/2020/10/201008104229.htm
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Zoologists uncover new example of rapid evolution -- meet the Sulawesi Babblers
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Zoologists from Trinity College Dublin, working in tropical Southeast Asia, have uncovered a modern-day example of rapid evolution in action.
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The zoologists have discovered that male and female Sulawesi Babblers (The research, completed with the support of the Irish Research Council and collaborators in Universitas Halu Oleo, is published today in the journal Fionn Ó Marcaigh, first author on the paper and a PhD Candidate in Trinity's School of Natural Sciences, said:"Tropical regions are home to more species of plants and animals than anywhere else, but many of these remain poorly understood even as they face imminent extinction. This is especially true of relatively non-descript species like the babblers, which are shy birds that feed in dense bushes all over the islands of Southeast Asia."Because male and female babblers have the same dull brown plumage, unlike familiar birds such as pheasants or peacocks, scientists previously thought that they did not show sexual dimorphism. Our discovery proves this wrong and provides another timely reminder that we have so much more to learn about tropical species if we are to understand how they are evolving on all the world's marvellous and diverse islands."We can't protect them if we don't understand them."The kind of sexual dimorphism in size displayed by the babblers is important because it enables the males and females to fill different "niches" in the ecosystem.There is an evolutionary theory stating that dimorphic species are likely to become more strongly dimorphic on islands than they are on the mainland, as it prevents them having to compete for scarcer resources. However, this is usually seen on very isolated islands where there has been ample time for populations to evolve separately.Fionn Ó Marcaigh added:"Our research is significant for showing the same process to have occurred on much younger islands, which were connected to the mainland by land-bridges only 30,000 years ago. This means that the difference in sexual dimorphism between mainland and island birds must have evolved quite rapidly, showing its importance for the ecology of the species."
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Animals
| 2,020 |
October 8, 2020
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https://www.sciencedaily.com/releases/2020/10/201008083807.htm
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Ants adapt tool use to avoid drowning
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Researchers have observed black imported fire ants using sand to draw liquid food out of containers, when faced with the risk of drowning. This is the first time this sophisticated tool use has been reported in animals. These findings are published in the British Ecological Society journal
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A laboratory experiment has shown for the first time that a species of ant has the remarkable ability to adapt its tool use. When provided with small containers of sugar water, black imported fire ants were able to float and feed on the surface, but when researchers reduced the surface tension, the ants started depositing sand grains on the inside of the container leading out of it."We found the ants used sand to build a structure that could effectively draw sugar water out of the container to then to be collected" said Dr Aiming Zhou, an associate professor at Huazhong Agricultural University, Wuhan, China, and a lead author of the research. "This exceptional tool making skill not only reduced the drowning risk of ants, but also provided a larger space for them to collect sugar water."The sand structures were found to be so efficient that they could syphon almost half of the sugar water out of the containers in five minutes.Researchers altered the surface tension of the sugar water by adding surfactant. When surfactant concentrations were over 0.05%, representing considerable drowning risk, ants were observed building the sand structures to syphon sugar water out of the container. These structures were never observed when ants foraged in containers of pure sugar water, indicating an adaptable approach to this novel tool use.The results not only demonstrate black imported fire ants' ability to use tools to forage but also that they can recognise an increased foraging risk and can adjust their tool use in response to this.Dr Jian Chen, Research Entomologist at The U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS), Stoneville Mississippi, and another author of the research, said: "We knew some ant species are able to use tools, particularly in collecting liquid food; however, we were surprised by such remarkable tool use displayed by black imported fire ants. Our findings suggest that ants and other social insects may have considerable high cognitive capabilities for unique foraging strategies"Tool use is seen as an indicator of cognitive sophistication and has mostly been observed in primates and some species of birds. But in invertebrates this behaviour is less well studied and has previously been thought of as hard wired and inflexible.Black imported fire ants, Solenopsis richteri, are native to South America but are now an invasive species in southern United States after being introduced. Their Hydrophobic exoskeletons allow them to float on water but it's likely that they still face frequent drowning risk in nature because of the importance of liquid foods like nectar and honeydew as a carbohydrate source.In the study the researchers calculated drowning risk by measuring the proportion of drowned ants in 2.5 cm containers of sugar water with differing concentrations of surfactant. The ants were able to float on the surface of pure sugar water, but the proportion of drowned ants increased significantly with increasing concentrations of surfactant. The researchers then provided ants with sands of varying grain size to test their preferences in creating sand structures when faced with different drowning risks.Dr Zhou cautions that further studies are needed in this research area, saying: "Our experiments are conducted in the laboratory and only limited to the black imported fire ants." The next steps will be to determine how widespread this behavior is in other ant species. Dr Chen adds: "Our study is the first to touch on this interesting topic. We hope our paper will motivate others to do the related investigations."
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Animals
| 2,020 |
October 8, 2020
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https://www.sciencedaily.com/releases/2020/10/201008091637.htm
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Hearts harvested from pigs may soon help solve chronic shortages of these donor organs
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The goal of harvesting hearts from pigs to solve the chronic shortage of these donor organs appears to be in reach, according to a new scientific review by researchers at Massachusetts General Hospital (MGH). This analysis, published in the journal
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A heart transplant is often the only hope of survival for patients with severe heart failure and certain other cardiac conditions that don't respond to other treatments. In 2019, surgeons in the United States performed 3,552 heart transplants, according to the United Network for Organ Sharing. A patient in need of a new heart typically waits more than six months for a donor organ to become available, and often much longer. For many, the wait is too long.Lead author Richard N. Pierson III, MD, an investigator in MGH's Division of Cardiac Surgery, and his coauthors discuss the scientific breakthroughs that have overcome obstacles to cardiac xenotransplantation. For example, the immune systems of baboons and other primates (including, presumably, humans) recognize pig hearts as "foreign" and attack them, leading to organ rejection. In response, scientists have used genetic engineering techniques to produce pigs whose organs lack certain carbohydrates that are the principal targets of the immune system.Genetic engineering has also helped solve another problem with cardiac xenotransplantation. Early experiments found that incompatibility between proteins in human blood and proteins on the lining of pig blood vessels could cause blood clots. Pierson and his colleagues have contributed to efforts to develop and test pigs that are engineered to carry genes responsible for producing a human version of a protein called thrombomodulin, which keeps clotting under control.Innovation in drug development has also made cardiac xenotransplantation possible. Transplant recipients must take drugs that suppress the immune system to prevent organ rejection. "But those drugs don't work when you put a pig organ into a baboon," says Pierson, suggesting that conventional immune suppression wouldn't work in humans, either. To solve this problem, Pierson collaborated with other researchers to develop monoclonal antibodies that block "costimulatory" molecules known as CD40 and CD154. These monoclonal antibodies prevent human or baboon immune cells from attacking pig organs much more effectively than conventional immunosuppressants.Finally, the Richard N. Pierson III, MD, is scientific director of the MGH Center for Transplantation Science and a professor of Surgery at Harvard Medical School. He holds the W. Gerald and Patricia Austen Chair in Cardiac Surgery.
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Animals
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October 7, 2020
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https://www.sciencedaily.com/releases/2020/10/201007123125.htm
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Past tropical forest changes drove megafauna and hominin extinctions
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In a paper published today in the journal
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"Southeast Asia is often overlooked in global discussions of megafauna extinctions," says Associate Professor Julien Louys who led the study, "but in fact it once had a much richer mammal community full of giants that are now all extinct."By looking at stable isotope records in modern and fossil mammal teeth, the researchers were able to reconstruct whether past animals predominately ate tropical grasses or leaves, as well as the climatic conditions at the time they were alive. "These types of analyses provide us with unique and unparalleled snapshots into the diets of these species and the environments in which they roamed," says Dr. Patrick Roberts of the MPI-SHH, the other corresponding author of this study.The researchers compiled these isotope data for fossil sites spanning the Pleistocene, the last 2.6 million years, as well as adding over 250 new measurements of modern Southeast Asian mammals representing species that had never before been studied in this way.They showed that rainforests dominated the area from present-day Myanmar to Indonesia during the early part of the Pleistocene but began to give way to more grassland environments. These peaked around a million years ago, supporting rich communities of grazing megafauna such as the elephant-like stegodon that, in turn, allowed our closest hominin relatives to thrive. But while this drastic change in ecosystems was a boon to some species, it also lead to the extinction of other animals, such as the largest ape ever to roam the planet: Gigantopithecus.However, as we know today, this change was not permanent. The tropical canopies began to return around 100,000 years ago, alongside the classic rainforest fauna that are the ecological stars of the region today.The loss of many ancient Southeast Asian megafauna was found to be correlated with the loss of these savannah environments. Likewise, ancient human species that were once found in the region, such as Homo erectus, were unable to adapt to the re-expansion of forests."It is only our species, Ironically, it is now rainforest megafauna that are most at risk of extinction, with many of the last remaining species critically endangered throughout the region as a result of the activities of the one surviving hominin in this tropical part of the world."Rather than benefitting from the expansion of rainforests over the last few thousand years, Southeast Asian mammals are under unprecedented threat from the actions of humans," says Louys. "By taking over vast tracts of rainforest through urban expansion, deforestation and overhunting, we're at risk of losing some of the last megafauna still walking the Earth."
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Animals
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October 7, 2020
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https://www.sciencedaily.com/releases/2020/10/201007123110.htm
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Mammals share gene pathways that allow zebrafish to grow new eyes
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Working with fish, birds and mice, Johns Hopkins Medicine researchers report new evidence that some animals' natural capacity to regrow neurons is not missing, but is instead inactivated in mammals. Specifically, the researchers found that some genetic pathways that allow many fish and other cold-blooded animals to repair specialized eye neurons after injury remain present in mammals as well, but are turned off, blocking regeneration and healing.
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A description of the study, published online by the journal "Our research overall indicates that the potential for regeneration is there in mammals, including humans, but some evolutionary pressure has turned it off," says Seth Blackshaw, Ph.D., professor of neuroscience at the Johns Hopkins University School of Medicine. "In fact, regeneration seems to be the default status, and the loss of that ability happened at multiple points on the evolutionary tree," he says.For the study, Blackshaw's team focused on supportive cells in the back of the eye. In zebrafish, a standard laboratory model whose genome has been well defined, these cells, known as Müller glia, respond and repair the light-sensitive retina by growing new cells in the central nervous system called neurons. In addition to regrowing eye tissue, zebrafish's regenerative abilities extend to other body parts, including fins, tails and some internal organs.The retina is a good testing ground for mapping genetic activity, explains Blackshaw, because it contains structures common to other cells in the nervous system. In previous studies, moreover, scientists have found that the genetic networks in the retina are well conserved across species, so comparisons among fish, birds, mice and even humans are possible.For the new experiments, the Johns Hopkins researchers created retinal injuries in zebrafish, chickens and mice. Then they used high-powered microscopes and a previously developed gene mapping tool to observe how the supportive Müller glia cells responded.Blackshaw said the team was surprised to find, immediately after the injury, that the cells in each of the three species behaved the same way: They entered an "active state" characterized by the activation of specific genes, some of which control inflammation.This active state, says Blackshaw, primarily helps to contain the injury and send signals to immune system cells to combat foreign invaders such as bacteria, or to clean up broken tissue.Beyond that step, however, the species' responses diverged.In zebrafish, active Müller glia began turning on a network of transcription factors that control which genes are 'on' and 'off.' In the current experiment, the NFI transcription factors activated genes that are linked to cell maturity, sending the Müller glia cells back in developmental time to a more primitive state, which then allows them to develop into many different cell types. The Müller glia then "differentiated" into new cells to replace the ones lost to injury.In contrast, the research team saw that chickens with damaged retinas activate only some of the transcription factor 'gene control switches' that are turned on in zebrafish. Thus, chickens have much less capability to create new Müller glia and other neurons in the eye following injury.Finally, the researchers looked at the injury response in mice. Mice share the vast majority of their DNA with humans, and their eyes are similar to human eyes. The researchers found that injured Müller glia in mice remained in the first "active" state for several days, much longer than the eight to 12 hours that zebrafish are in this state, and yet never acquired the ability to make new neurons.Müller glia in all three species also express high levels of nuclear factor I (NFI) transcription factors, but rapidly turn them off following injury. In mice, however, the NFI genes are turned back on soon thereafter, and actively block the Müller glia from generating neurons.The researchers found, to their surprise, they say, that the same genes that allowed the zebrafish cells to regenerate were "primed and ready to go" in the mouse eye, but that the "on" transcription factor was never activated. Instead, the NFI factors actively block the cells' regenerative potential.Blackshaw suspects that animals with a higher potential to develop disease in brain and other neurological tissue may have lost this capability over evolutionary time to help protect and stabilize other brain cells. "For example, we know that certain viruses, bacteria and even parasites can infect the brain. It could be disastrous if infected brain cells were allowed to grow and spread the infection through the nervous system," says Blackshaw.Now equipped with a more detailed map of the cellular response to neuronal injury and regrowth, scientists may be able to find a way to activate the regenerative capabilities hidden in human DNA, Blackshaw says.Video:
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Animals
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October 7, 2020
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https://www.sciencedaily.com/releases/2020/10/201007123105.htm
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Paleontologists identify new species of mosasaur
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A new species of an ancient marine reptile evolved to strike terror into the hearts of the normally safe, fast-swimming fish has been identified by a team of University of Alberta researchers, shedding light on what it took to survive in highly competitive ecosystems.
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More than a dozen types of mosasaur -- which can reach 17 metres in length and resemble an overgrown komodo dragon -- ruled over the marine environment in what is now Morocco at the tail end of the Late Cretaceous period between 72 and 66 million years ago.What differentiates Strong's version, however, is that it features a long, narrow snout and interlocking teeth -- similar to the crocodilian gharials, a relative of crocodiles and alligators.Strong said this discovery adds a layer of clarity to a diverse picture seemingly overcrowded with mega-predators all competing for food, space and resources."Its long snout reflects that this mosasaur was likely adapted to a specific form of predation, or niche partitioning, within this larger ecosystem."Strong explained there is evidence that each species of the giant marine lizard shows adaptations for different prey items or styles of predation."For some species, these adaptations can be very prominent, such as the extremely long snout and the interlocking teeth in Gavialimimus, which we hypothesized as helping it to catch rapidly moving prey," she said.She added another distinctive species would be Globidens simplex -- described last year by the Caldwell lab -- which has stout, globular teeth adapted for crushing hard prey like shelled animals."Not all of the adaptations in these dozen or so species are this dramatic, and in some cases there may have been some overlap in prey items, but overall there is evidence that there's been diversification of these species into different niches," Strong noted.Alternatively, the main contrasting hypothesis would be a scenario of more direct competition among species. Strong said given the anatomical differences among these mosasaurs, though, the idea of niche partitioning seems more consistent with the anatomy of these various species."This does help give another dimension to that diversity and shows how all of these animals living at the same time in the same place were able to branch off and take their own paths through evolution to be able to coexist like that," she said.The remains of the "Morocco is an incredibly good place to find fossils, especially in these phosphate mines," Strong said. "Those phosphates themselves reflect sediments that would have been deposited in marine environments, so there are a lot of mosasaurs there."
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Animals
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October 7, 2020
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https://www.sciencedaily.com/releases/2020/10/201007123031.htm
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Feline friendly? How to build rap-paw with your cat
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A team of psychologists at the Universities of Sussex and Portsmouth have purr-fected the art of building a bond with cats.
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The new study 'The role of cat eye narrowing movements in cat-human communication', published online in the Nature journal The team, led by Dr Tasmin Humphrey and Professor Karen McComb, animal behaviour scientists at the University of Sussex, undertook two experiments. The first revealed that cats are more likely to slow blink at their owners after their owners have slow blinked at them, compared to when they don't interact at all. The second experiment, this time with a researcher from the psychology team, rather than the owner, found that the cats were more likely to approach the experimenter's outstretched hand after they'd slow blinked at the cat, compared to when they had adopted a neutral expression. Taken together, the study shows that this slow blinking technique can provide a form of positive communication between cats and humans.Professor Karen McComb, from the School of Psychology at the University of Sussex, who supervised the work, said: "As someone who has both studied animal behaviour and is a cat owner, it's great to be able to show that cats and humans can communicate in this way. It's something that many cat owners had already suspected, so it's exciting to have found evidence for it."This study is the first to experimentally investigate the role of slow blinking in cat-human communication. And it is something you can try yourself with your own cat at home, or with cats you meet in the street. It's a great way of enhancing the bond you have with cats. Try narrowing your eyes at them as you would in a relaxed smile, followed by closing your eyes for a couple of seconds. You'll find they respond in the same way themselves and you can start a sort of conversation."Dr Tasmin Humphrey, a PhD student in the School of Psychology at the University of Sussex during the work, who was the first author of the study said: "Understanding positive ways in which cats and humans interact can enhance public understanding of cats, improve feline welfare, and tell us more about the socio-cognitive abilities of this under-studied species."Our findings could potentially be used to assess the welfare of cats in a variety of settings, including veterinary practices and shelters."In terms of why cats behave in this way, it could be argued that cats developed the slow blink behaviours because humans perceived slow blinking as positive. Cats may have learned that humans reward them for responding to slow blinking. It is also possible that slow blinking in cats began as a way to interrupt an unbroken stare, which is potentially threatening in social interaction.Dr Leanne Proops at University of Portsmouth who co-supervised the work said: "It's definitely not easy to study natural cat behaviour so these results provide a rare insight in to the world of cat-human communication."Two experiments were conducted to explore the significance of the slow blink in cat-human communication. The first experiment included a total of 21 cats from 14 different households. Fourteen different owners participated in experiment 1. Ten of the cats were male and 11 of the cats were female, with cat age ranging from an estimated 0.45-16 years. The experiments took place in each cat's home. The psychologist advised the cat's owner on how to slow blink. Once the cat had settled down in one place, the psychologist asked the owner to either sit approximately 1 m away from the cat.Experiment 2 included a total of 24 additional cats. Twelve cats were male and 12 cats were female, with cat age ranging from an estimated 1-17 years old. The cats included in the final analyses were from 8 different households. In this experiment, the researcher, who was unfamiliar to the cat, either slow blinked at the cat or adopted a neutral face without direct eye contact. This experiment also tested which context the cats preferred to approach the unfamiliar experimenter, by them offering the cat a flat hand with palm faced upwards whilst sat or crouched directly opposite the cat. Both experiments were video recorded.In the new paper, the authors provide some context for their findings. The psychology of cats hasn't been studied as extensively as dogs, but what is already known includes:
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Animals
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October 7, 2020
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https://www.sciencedaily.com/releases/2020/10/201007093631.htm
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Molecular mechanism of cross-species transmission of primate lentiviruses
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Humans are exposed continuously to the menace of viral diseases such as those caused by the Ebola virus, Zika virus and coronaviruses. Such emerging/re-emerging viral outbreaks can be triggered by cross-species viral transmission from wild animals to humans.
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To achieve cross-species transmission, new hosts have to be exposed to the virus from the old host. Next, the viruses acquire certain mutations that can be beneficial for replicating in the new hosts. Finally, through sustained transmission in the new host, the viruses adapt further evolving as a new virus in the new host. However, at the outset of this process, the viruses have to overcome "the species barriers," which hamper viral cross-species transmission. Mammals including humans have "intrinsic immunity" mechanisms that have diverged enough in evolution to erect species barriers to viral transmission.HIV-1, the causative agent of AIDS, most likely originated from related precursors found in chimpanzees (SIVcpz) and gorillas (SIVgor), approximately 100 years ago.Additionally, SIVgor most likely emerged through the cross-species jump of SIVcpz from chimpanzees to gorillas.However, it remains unclear how primate lentiviruses successfully transmitted among different species. To limit cross-species lentiviral transmission, cellular "intrinsic immunity," including APOBEC3 proteins potentially inhibit lentiviral replication. In contrast, primate lentiviruses in this evolutionary "arms race" have acquired their own "weapon," viral infectivity factor (Vif), to antagonize the antiviral effect of restriction factors.A research group at The Institute of Medical Science, The University of Tokyo (IMSUT) showed that gorilla APOBEC3G potentially plays a role in inhibiting SIVcpz replication. Intriguingly, the research group demonstrated that an amino acid substitution in SIVcpz Vif, M16E, is sufficient to overcome gorilla APOBEC3G-mediated restriction."To our knowledge, this is the first report suggesting that a great ape APOBEC3 protein can potentially restrict the cross-species transmission of great ape lentiviruses and how lentiviruses overcame this species barrier. Moreover, this is the first investigation elucidating the molecular mechanism by which great ape lentiviruses achieve cross-species transmission," said the lead scientist, Kei Sato, Associate Professor (Principal Investigator) in the Division of Systems Virology, Department of Infectious Disease Control, IMSUT.
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Animals
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October 6, 2020
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https://www.sciencedaily.com/releases/2020/10/201006220209.htm
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Toothless dino's lost digits point to spread of parrot-like species
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A newly discovered species of toothless, two-fingered dinosaur has shed light on how a group of parrot-like animals thrived more than 68 million years ago.
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The unusual species had one less finger on each forearm than its close relatives, suggesting an adaptability which enabled the animals to spread during the Late Cretaceous Period, researchers say.Multiple complete skeletons of the new species were unearthed in the Gobi Desert in Mongolia by a University of Edinburgh-led team.Named Oksoko avarsan, the feathered, omnivorous creatures grew to around two metres long and had only two functional digits on each forearm. The animals had a large, toothless beak similar to the type seen in species of parrot today.The remarkably well-preserved fossils provided the first evidence of digit loss in the three-fingered family of dinosaurs known as oviraptors.The discovery that they could evolve forelimb adaptations suggests the group could alter their diets and lifestyles, and enabled them to diversify and multiply, the team says.Researchers studied the reduction in size, and eventual loss, of a third finger across the oviraptors' evolutionary history. The group's arms and hands changed drastically in tandem with migrations to new geographic areas -- specifically to what is now North America and the Gobi Desert.The team also discovered that Oksoko avarsan -- like many other prehistoric species -- were social as juveniles. The fossil remains of four young dinosaurs were preserved resting together.The study, published in the journal Royal Society Open Science, was funded by The Royal Society and the Natural Sciences and Engineering Council of Canada. It also involved researchers from the University of Alberta and Philip J. Currie Dinosaur Museum in Canada, Hokkaido University in Japan, and the Mongolian Academy of Sciences.Dr Gregory Funston, of the University of Edinburgh's School of GeoSciences, who led the study, said: "Oksoko avarsan is interesting because the skeletons are very complete and the way they were preserved resting together shows that juveniles roamed together in groups. But more importantly, its two-fingered hand prompted us to look at the way the hand and forelimb changed throughout the evolution of oviraptors -- which hadn't been studied before. This revealed some unexpected trends that are a key piece in the puzzle of why oviraptors were so diverse before the extinction that killed the dinosaurs."
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Animals
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October 6, 2020
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https://www.sciencedaily.com/releases/2020/10/201006165738.htm
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New study rebuts 75-year-old belief in reptile evolution
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Challenging a 75-year-old notion about how and when reptiles evolved during the past 300 million-plus years involves a lot of camerawork, loads of CT scanning, and, most of all, thousands of miles of travel. Just check the stamps in Tiago R. Simões ' passport.
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Simões is the Alexander Agassiz Postdoctoral Fellow in the lab of Harvard paleontologist Stephanie Pierce. From 2013 to 2018, he traveled to more than 20 countries and more than 50 different museums to take CT scans and photos of nearly 1,000 reptilian fossils, some hundreds of millions of years old. It amounted to about 400 days of active collection, helping form what is believed to be the largest available timeline on the evolution of major living and extinct reptile groups.Now, a statistical analysis of that vast database is helping scientists better understand the evolution of these cold-blooded vertebrates by contradicting a widely held theory that major transitions in evolution always happened in big, quick (geologically speaking) bursts, triggered by major environmental shifts. The findings are described in a recently published paper in In it, researchers show that the evolution of extinct lineages of reptiles from more than 250 million years ago took place through many small bursts of morphological changes, such as developing armored body plans or wings for gliding, over a period of 50 million years instead of during a single major evolutionary event, as previously thought. They also show that the early evolution of most lizard lineages was a continuously slower and more incremental process than previously understood."It wasn't a sudden jump that kind of established the wide diversity that we see today in reptiles," Simões said. "There was an initial jump, but relatively small, and then a sustained increase over time of those rates [of evolution] and different diversity values."Evidence of this has been seen in other types of animals, but this is the first time it's been seen in reptiles -- one of the most diverse animals on the planet, with more than 10,000 different species and a dizzying variety of abilities and traits. Consider how some lizard species can freeze solid overnight then thaw the next morning, or how turtles grow protective armor.The findings run contrary to the evolutionary theory of adaptive radiation that Harvard paleontologist George G. Simpson popularized in the 1940s, which sought to explain the origins of the planet's biological diversity. Adaptive radiation has been the focus of intense investigation for decades, but wasn't until recent years that the technology, methods, and data have existed to precisely measure rapid rates of evolution in the fossil record in terms of different animal species, morphologies, and at the molecular level using DNA.Researchers of this study also included Pierce, the Thomas D. Cabot Associate Professor of Organismic and Evolutionary Biology and curator of vertebrate paleontology in the Museum of Comparative Zoology; Oksana Vernygora, a graduate student from the University of Alberta in Canada; and Professor Michael Wayne Caldwell at Alberta.Simões traveled to almost all of the world's major natural history museums to collect the data for the study, including the national natural history museums in London, Paris, Berlin, Ottawa, Beijing, and Tokyo. In the U.S., he visited the Smithsonian National Museum of Natural History, the Carnegie Museum of Natural History, and Harvard's Museum of Comparative Zoology.The scientists believe that by understanding how animals evolve over longer periods of time, they can glean a number of lessons on ecology and how organisms are affected by environmental changes. Using the database, researchers can determine when major reptile lineages or morphologies originated, see how those changes affected reptile DNA, and learn important lessons about how species were impacted by historical events.Reptiles, for instance, have survived three major mass extinction events. The biggest was the Permian-Triassic mass extinction about 250 million years ago that killed about 90 percent of the planet's species, earning it the moniker the Great Dying. It's believed to have been caused by a buildup of natural greenhouse gases.The timeline researchers created found that the rates at which reptiles were evolving and the anatomical differences among them before the Great Dying were nearly as high as after the event. However, it was only much after the Great Dying that reptiles became dominant in many ecosystems and extremely diverse in terms of the number of different species.That finding cemented that fast rates of anatomical change don't need to coincide with genetic diversity or an abundance of species (called taxonomic diversity), and further rebutted adaptive radiation as the only explanation for the origin of new animal groups and body plans. The researchers also note that it took reptiles almost 10 million years to recover to previous levels of anatomical diversity."That kind of tells you on the broad scheme of things and on a global scale how much impact, throughout the history of life, sudden environmental changes may have," Simões said.Further evidence that contradicted adaptive radiation included similar but surprising findings on the origins of snakes, which achieved the major aspects of their skinny, elongated body plans early in their evolution about 170 million years ago (but didn't fully lose their limbs for another 105 million years). They also underwent rapid changes to their skulls about 170 to 165 million years ago that led to such powerful and flexible mouths that today they can swallow whole prey many times their size. But while snakes experienced the fastest rates of anatomical change in the history of reptile evolution, these changes did not coincide with increases in taxonomic diversity or high rates of molecular evolution as predicted by adaptive radiations, the researchers said.The scientists weren't able to pinpoint why this mismatch happens, and suggested more research is needed. In particular they want to understand how body plans evolve and how changes in DNA relate to it."We can see better now what are the big changes in the history of life and especially in the history of reptile life on Earth," Simões said. "We will keep digging."
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Animals
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October 6, 2020
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https://www.sciencedaily.com/releases/2020/10/201006153503.htm
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Evolution of the Y chromosome in great apes deciphered
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New analysis of the DNA sequence of the male-specific Y chromosomes from all living species of the great ape family helps to clarify our understanding of how this enigmatic chromosome evolved. A clearer picture of the evolution of the Y chromosome is important for studying male fertility in humans as well as our understanding of reproduction patterns and the ability to track male lineages in the great apes, which can help with conservation efforts for these endangered species.
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A team of biologists and computer scientists at Penn State sequenced and assembled the Y chromosome from orangutan and bonobo and compared those sequences to the existing human, chimpanzee, and gorilla Y sequences. From the comparison, the team were able to clarify patterns of evolution that seem to fit with behavioral differences between the species and reconstruct a model of what the Y chromosome might have looked like in the ancestor of all great apes.A paper describing the research appears October 5, 2020 in the journal "The Y chromosome is important for male fertility and contains the genes critical for sperm production, but it is often neglected in genomic studies because it is so difficult to sequence and assemble," said Monika Cechova, a graduate student at Penn State at the time of the research and co-first author of the paper. "The Y chromosome contains a lot of repetitive sequences, which are challenging for DNA sequencing, assembling sequences, and aligning sequences for comparison. There aren't out-of-the-box software packages to deal with the Y chromosome, so we had to overcome these hurdles and optimize our experimental and computational protocols, which allowed us to address interesting biological questions."The Y chromosome is unusual. It contains relatively few genes, many of which are involved in male sex determination and sperm production; large sections of repetitive DNA, short sequences repeated over and over again; and large DNA palindromes, inverted repeats that can be many thousands of letters long and read the same forwards and backwards.Previous work by the team comparing human, chimpanzee, and gorilla sequences had revealed some unexpected patterns. Humans are more closely related to chimpanzees, but for some characteristics, the human Y was more similar to the gorilla Y."If you just compare the sequence identity -- comparing the As,Ts, Cs, and Gs of the chromosomes -- humans are more similar to chimpanzees, as you would expect," said Kateryna Makova, Pentz Professor of Biology at Penn State and one of the leaders of the research team. "But if you look at which genes are present, the types of repetitive sequences, and the shared palindromes, humans look more similar to gorillas. We needed the Y chromosome of more great ape species to tease out the details of what was going on."The team, therefore, sequenced the Y chromosome of a bonobo, a close relative of the chimpanzee, and an orangutan, a more distantly related great ape. With these new sequences, the researchers could see that the bonobo and chimpanzee shared the unusual pattern of accelerated rates of DNA sequence change and gene loss, suggesting that this pattern emerged prior to the evolutionary split between the two species. The orangutan Y chromosome, on the other hand, which serves as an outgroup to ground the comparisons, looked about like what you expect based on its known relationship to the other great apes."Our hypothesis is that the accelerated change that we see in chimpanzees and bonobos could be related to their mating habits," said Rahulsimham Vegesna, a graduate student at Penn State and co-first author of the paper. "In chimpanzees and bonobos, one female mates with multiple males during a single cycle. This leads to what we call 'sperm competition,' the sperm from several males trying to fertilize a single egg. We think that this situation could provide the evolutionary pressure to accelerate change on the chimpanzee and bonobo Y chromosome, compared to other apes with different mating patterns, but this hypothesis, while consistent with our findings, needs to be evaluated in subsequent studies."In addition to teasing out some of the details of how the Y chromosome evolved in individual species, the team used the set of great ape sequences to reconstruct what the Y chromosome might have looked like in the ancestor of modern great apes."Having the ancestral great ape Y chromosome helps us to understand how the chromosome evolved," said Vegesna. "For example, we can see that many of the repetitive regions and palindromes on the Y were already present on the ancestral chromosome. This, in turn, argues for the importance of these features for the Y chromosome in all great apes and allows us to explore how they evolved in each of the separate species."The Y chromosome is also unusual because, unlike most chromosomes it doesn't have a matching partner. We each get two copies of chromosomes 1 through 22, and then some of us (females) get two X chromosomes and some of us (males) get one X and one Y. Partner chromosomes can exchange sections in a process called 'recombination,' which is important to preserve the chromosomes evolutionarily. Because the Y doesn't have a partner, it had been hypothesized that the long palindromic sequences on the Y might be able to recombine with themselves and thus still be able to preserve their genes, but the mechanism was not known."We used the data from a technique called Hi-C, which captures the three-dimensional organization of the chromosome, to try to see how this 'self-recombination' is facilitated," said Cechova. "What we found was that regions of the chromosome that recombine with each other are kept in close proximity to one another spatially by the structure of the chromosome.""Working on the Y chromosome presents a lot of challenges," said Paul Medvedev, associate professor of computer science and engineering and of biochemistry and molecular biology at Penn State and the other leader of the research team. "We had to develop specialized methods and computational analyses to account for the highly repetitive nature of the sequence of the Y. This project is truly cross-disciplinary and could not have happened without the combination of computational and biological scientists that we have on our team."
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Animals
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October 6, 2020
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https://www.sciencedaily.com/releases/2020/10/201006114239.htm
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The first human settlers on islands caused extinctions
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Though some believe prehistoric humans lived in harmony with nature, a new analysis of fossils shows human arrival in the Bahamas caused some birds to be lost from the islands and other species to be completely wiped out.
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The researchers examined more than 7,600 fossils over a decade and concluded that human arrival in the Bahamas about 1,000 years ago was the main factor in the birds' extinction and displacement in recent millennia, although habitat fluctuations caused by increased storm severity and sea level rise could have played a role.Many spectacular species, such as a colorful parrot, a striking scavenger called a caracara, and a number of hawks, doves, owls, and songbirds, were still found as recently as 900 years ago, and may have overlapped with people by a century before disappearing or retreating to only one or two islands in The Bahamas. "No other environmental change could explain their loss," said study co-lead Janet Franklin, a distinguished professor of botany and plant sciences at UC Riverside.Full results of Franklin's study were published this week in the For example, the Abaco parrot is now only found on two islands in the Bahamas. There are many islands in between the two where the parrots now live that have the same habitat."We wondered why those parrots aren't found in the middle islands," Franklin said. "It turns out, they were, not that long ago." Franklin and her collaborator, ornithologist David Steadman of University of Florida, found Abaco parrot fossils were on all the islands until 1,000 years ago.The study was also able to identify losses of bird species that lived in the Bahamas since the end of the last ice age, more than 10,000 years before people arrived. These species included a giant barn owl and giant eagle -- predators whose prey also disappeared from the islands after people arrived.More than two thirds of the 90 bird species identified in the fossils that date from the end of the last ice age. Either they have gone altogether extinct or now only persist outside of the Bahamas.The Bahamian islands are "treasure troves" of fossils because the limestone caves and flooded sinkholes there act as natural traps and are highly effective at preserving bones. Because they're relatively small land areas lacking mountains or steep, remote areas where plants and animals can retreat to avoid people, the islands are also places where humans can have a big impact.Giant predator birds likely competed with people for food such as giant tortoises -- now extinct -- and hutia, the only native land mammal in the Bahamas, which resembles a large guinea pig. In addition, humans hunt birds that eat fruit, because they tend to be fatter and more delicious.It isn't clear how much of the effect on birds is attributable to habitat change caused by people settling on the islands and how much was due to direct human predation. But Franklin said the wild habitat requires protections to preserve the animals that remain."The species here are the ones that survived," Franklin said. "They might be more adaptable than other birds, and less dependent on a niche or habitat that's strongly affected by human activity. But they are still vulnerable and worth conserving."Furthermore, the researchers note in the study that "the related futures of biodiversity and humanity perhaps never have been at a crossroads more than now. The transfer of a zoonotic disease from wildlife to humans, which has resulted in a global pandemic, is directly linked to biodiversity loss."In other words, as humans increasingly take over wild habitat, particularly rainforests, there are more opportunities for diseases to jump from wildlife to people."Protecting rainforests and regulating wildlife trade helps the animals and is also a component of preventing pandemics," Franklin said.
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October 6, 2020
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https://www.sciencedaily.com/releases/2020/10/201006091231.htm
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Battling with neighbors could make animals smarter
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From ants to primates, 'Napoleonic' intelligence has evolved to help animals contend with the myriad cognitive challenges arising from interactions with rival outsiders, suggest researchers at the University of Bristol in a paper published in
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Antagonistic and co-operative social interactions within groups have long been suggested to drive the evolution of big brains. But animals from across the social spectrum must constantly juggle threats and opportunities from outsiders too.Interactions with outsiders have been little considered in the context of cognitive evolution. Drawing on their varied backgrounds in animal cognition, intergroup conflict and social evolution, the Bristol scientists have expanded the Social Intelligence Hypothesis to include this missing social axis.Dr Ben Ashton, honorary research associate and lead author from the School of Biological Sciences, said: "Outside threats and opportunities likely present a range of cognitive challenges. Animals have to defend their territories, find mates and compete for resources -- we believe negotiating such challenges requires considerable brain power."Andy Radford, Professor of Behavioural Ecology and senior author, continued: "A vast amount of time and effort in the animal kingdom is devoted to gathering information about outsiders, and to avoiding, exploiting and winning interactions with them. But this aspect of sociality has traditionally been ignored in explanations of animal brain evolution."Dr Patrick Kennedy, research associate and co-author added: "Biologists have shown how interactions with groupmates can generate 'Machiavellian' intelligence, the House of Cards-style cunning needed to get ahead in social politics within groups. We argue that animals also need 'Napoleonic' intelligence, the more Game of Thrones-style sharpness necessary to triumph in a world packed with rival outsiders."Niccolò Machiavelli is perhaps best-known for his political treatise The Prince, a commentary on how to establish and retain power; the term Machiavellian subsequently became synonymous with ruthless realpolitik. Napoleon Bonaparte is considered one of the greatest military minds in history; the strategic intelligence underlying the Napoleonic campaigns is still used as an example in textbook warfare today.Dr Ashton, now at Macquarie University, Australia, said: "Cognitive evolution is one of the most hotly debated topics in biology, with considerable uncertainty remaining over the predominant drivers. Some of that uncertainty might be because a whole social axis -- interactions with rival outsiders -- has been largely ignored in both theoretical and empirical work."Dr Kennedy added: "The possibility that outsiders have shaped intelligence has been suggested before, in particular by two of the pioneers of social evolution -- Richard Alexander and William Hamilton. However, these brainy primates were thinking only of our own species; it is time to expand their insights beyond human cognition."Professor Radford concluded: "What do big-brained animals have in common with Napoleon Bonaparte? We suspect that their ancestors possessed the intelligence to triumph in one of the highest-stakes games of all: outmanoeuvring outsiders."
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Animals
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October 5, 2020
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https://www.sciencedaily.com/releases/2020/10/201005140825.htm
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Dog brains do not prefer faces
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Even though dogs gaze into man's eyes, dog brains may not process faces as human brains do. A new study from
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Faces constitute a critical part of communication for humans and other primates, so much so that faces have a special status in their visual system. Areas in the face network, like the fusiform face area, activate specifically to faces. Dogs care about faces, too, but they may not have face areas.Bunford, Hernández-Pérez et al. used fMRI to compare the brain activity of humans and pet dogs as they watched brief videos of other humans and dogs. Human brains showed a preference for faces, meaning that some visual areas had greater activity in response to a face compared to the back of the head. A subset of these regions also displayed species preference, with increased activity in response to viewing a human over a dog. In contrast, dog brains only showed species preference. Visual areas had greater activity in response to seeing a dog over a human, and no activity difference between seeing a face vs. the back of the head.
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Animals
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October 5, 2020
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https://www.sciencedaily.com/releases/2020/10/201005101527.htm
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First rehoming of laboratory dogs in Finland successful but required a great deal of work
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The rehoming of laboratory dogs was the first of its kind in Finland. The rehoming process was started with months of practising basic pet dog skills with the dogs and by familiarising them with the world outside the laboratory.
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The practice period lasted from four to six months, depending on the dog."However, we found out that the socialisation time was not quite sufficient for all dogs; owners reported that some dogs continued to be timid and suffer from separation anxiety. The laboratory dog rehoming process would be smoother if in the future laboratory dog facilities separated out the defaecation and rest areas, gave dogs access to an outside area and walked them outside on a leash," says Docent Marianna Norring from the Faculty of Veterinary Medicine at the University of Helsinki.The dogs had been living in packs of eight dogs for two to eight years in the University's laboratory animal facilities, from where they had daily access to an enclosed outside space. They spent the nights in smaller groups of dogs.At the University, the dogs had participated in both animal cognition and veterinary medical studies. The cognition research provided basic information on canine minds, and a new tranquillising agent suitable for dogs was developed in the veterinary medical study. The University of Helsinki does not currently have laboratory dogs.The rehoming of laboratory dogs was implemented as a collaboration between SEY Animal Welfare Finland and the University of Helsinki. A large group of individuals participated in socialising the dogs and acquainting them with life outside the facility: animal caretakers, researchers, animal-rights campaigners and dog trainers. The aim was to take into account the individual characteristics of each dog when searching for a new home for them. Whenever possible, dogs were rehomed in pairs. Generally speaking, the new owners have been extremely happy about their new pets.For the study, the dog rehoming process was monitored at the University for four years by interviewing the participants and collecting information from the new owners.
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Animals
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October 5, 2020
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https://www.sciencedaily.com/releases/2020/10/201005101521.htm
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Hunger encourages risk-taking
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The lives of animals in the wild are full of risky situations with uncertain outcomes. Whether they are exploring new habitats in unfamiliar terrain or searching for new food sources, they run the risk of being caught and killed by a predator. In many instances, their very survival depends on a single decision. Whether an animal decides to take a risk or prefers to avoid danger varies greatly from one individual to another.
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"Just as there are humans who are more cautious and others who take more risks, among animals of a particular species there are also individuals that are more or less risk-averse," says population ecologist Prof. Holger Schielzeth of the University of Jena. These differences are to some degree innate, but to a considerable extent they also depend on an individual's development. As Prof. Schielzeth, his Bielefeld colleague Prof. Klaus Reinhold and their research teams have now shown in an extensive meta-analysis, an animal's risk appetite is decisively influenced by the nutritional conditions it experiences while growing up. The researchers report on their findings in the latest issue of the specialist journal The researchers, working with lead author Nicholas Moran, analysed more than 120 experimental studies involving over 100 animal species and the results. Species studied included spiders, insects, crustaceans, fish, amphibians and birds. Common to all the studies was the fact that the animals had experienced phases of good and bad nutrition, and that their risk appetite was measured later in life. There were two opposing hypotheses: "On the one hand, one could assume that animals that have always enjoyed good circumstances and are therefore in a better condition would have more to lose and would therefore be more risk-averse," says evolutionary biologist Reinhold. On the other hand, he adds, a better nutritional status could mean that an animal would escape more easily from a risky situation, and would therefore be more likely to take a risk.The analysis of the results of all the studies has now made things clear. An insufficient food supply causes animals to engage in higher-risk behaviour: the willingness to take risks rises by an average of 26 per cent in animals that have experienced hunger earlier in their lives."We were surprised that this result was so clear and unambiguous," says Schielzeth. The correlation applied to virtually all the behavioural contexts studied, such as exploration behaviour, migration and risky searches for food. There were of course variations in the strength of the effect. Nevertheless, Schielzeth assumes that this correlation could also exist in humans, at least to some extent, as we are, after all, also an "animal species."This meta-analysis was carried out within the framework of the Collaborative Research Centre Transregio 212, "A Novel Synthesis of Individualisation across Behaviour, Ecology and Evolution: Niche Choice, Niche Conformance, Niche Construction" (NC3), which is based at the universities of Bielefeld and Münster, and in which the University of Jena is also involved. Dr Nicholas Moran is currently an MSCA Research Fellow at the National Institute of Aquatic Resources, Technical University of Denmark.
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Animals
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October 1, 2020
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https://www.sciencedaily.com/releases/2020/10/201001113632.htm
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Blue whales switch to daytime singing before migrating
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The blue whale is the largest animal on Earth. It's also among the loudest.
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"Sound is a vital mode of communication in the ocean environment, especially over long distances," said William Oestreich, a graduate student in biology at Stanford University's Hopkins Marine Station. "Light, or any sort of visual cue, is often not as effective in the ocean as it is on land. So many marine organisms use sound for a variety of purposes, including communicating and targeting food through echolocation."Although whale songs have been studied for decades, researchers have had limited success in deciphering their meaning. Now, by recording both individual whales and their greater populations in the Northeast Pacific, researchers from Stanford and the Monterey Bay Aquarium Research Institute (MBARI) have identified patterns in the trills and bellows of blue whales that indicate when the animals are migrating from their feeding grounds off the North American coast to their breeding grounds off Central America. Their research was published Oct. 1 in "We decided to compare daytime and nighttime song patterns from month to month, and there, in the divergence and convergence of two lines, was this beautiful signal that neither of us really expected," said John Ryan, a biological oceanographer at MBARI and senior author of the paper. "As soon as that image popped up on the screen, Will and I were both like, 'Hello, behavior.'"Further analysis across the five years of hydrophone recordings could reveal new information about blue whale migration, a 4,000-mile journey that ranks among the longest in the world -- and which the creatures repeat every year. Despite the immensity of blue whales and their travels, scientists know very little about their behaviors, such as how they are responding to changes in the ecosystem and food supply from year to year. Being able to predict the travel of whales along this important route could also help prevent ship strikes.To capture whales singing solo and in chorus, the researchers used two advanced recording technologies: an underwater microphone -- or hydrophone -- and tags that the researchers placed on individual whales.In 2015, MBARI deposited a hydrophone 18 miles off the Monterey coast, 3,000 feet (900 meters) under sea level. The hydrophone is wired to their MARS undersea cabled observatory, which provides it with power and communications. This seafloor eavesdropper has recorded the deep ocean soundscape almost continuously for more than five years."The hydrophone fits in your hand," said Ryan, who recommends listening to the hydrophone livestream in fall for optimal whale music (although only the humpback whale song can be heard through ordinary speakers). "It's a little instrument that produces big data -- about two terabytes per month."By focusing on the whale song wavelengths in the hydrophone data, the researchers noticed a distinct change over several months. Through the summers, the whale arias grew louder and were sung mostly at nighttime. Over the five years of data, the whale chorus was loudest around October and November, and singing happened more at nighttime. Following each annual peak in song activity, as the whales began to depart for warmer waters, singing became more of a daytime activity.While daytime versus nighttime differences in singing behavior had been noted in previous research, the whale-borne tags, developed by the lab of Stanford biologist Jeremy Goldbogen, helped explain what these 24-hour patterns and their inversion in late autumn could mean. Fifteen tags tracked the sounds of their carriers through accelerometer measurements -- which monitor vibrations -- and, in some cases, integrated hydrophones. In the summer, the whales spent much of the daytime feasting, bulking up for the long journey ahead and reserved their musical interludes for nighttime. When the time came, migration was again accompanied by daytime songs."In the hydrophone data, we saw really strong patterns over this enormous spatial domain. When we saw the exact same pattern on individual animals, we realized that what we'd been measuring over hundreds of kilometers is actually a real behavioral signal -- and one that represents the behavior of many different whales," said Oestreich. "As an ecologist, it's very exciting to observe so many whales, simultaneously, using one instrument."This research lays the groundwork for possibly predicting blue whale migration based on the transitions between the different song schedules -- such forecasts could be used to warn shipping lanes further down the coast, like air traffic control but for the ocean. The researchers also hope that further analysis of the acoustic data will reveal more about whale behavior in response to environmental changes, such as warming waters and fickle food supplies."If, for example, we can detect differences in migration and foraging in response to changes in the environment, that is a really powerful and important way to keep an eye on this critically endangered species," said Goldbogen, who is an assistant professor of biology in the School of Humanities and Sciences and also senior author of the paper. "That's economically important, ecologically important and also culturally important."Already, Oestreich is pursuing a related question: If we can use this signal to determine whether whales are foraging or migrating, are whales using it that way too? It's possible, said Oestreich, that a lone whale might listen around before giving up on feeding and heading south."Blue whales exist at incredibly low densities with enormous distances between them but, clearly, are sharing information in some way," said Oestreich. "Trying to understand that information sharing is one motivation, but also potentially using that signaling as a means to study them is another exciting possibility."This research was funded by the National Science Foundation, Stanford University, the David and Lucile Packard Foundation, the Office of Naval Research, the Office of Naval Operations (Living Marine Resources program) and the California Ocean Alliance. This research was conducted under National Marine Fisheries Service permit 16111 and 21678.
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Animals
| 2,020 |
October 1, 2020
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https://www.sciencedaily.com/releases/2020/10/201001090118.htm
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Planaria flatworms can be alternative screening tool to avoid rabbit skin testing
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Tests for skin treatments could be screened using flatworms rather than other animals such as rabbits, according to new research.
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A team at the University of Reading and Newcastle University have found that planaria, a type of flatworm, can be used as a reliable alternative for testing topical skin products used to treat human tissues such as the eyes, nose or vagina to ensure that they are not harmful.The paper, published in The tests are cheaper and more ethical than existing animal tests, because planaria are readily available and easily cultured in a laboratory -- and don't experience suffering. While other tests are carried out on human skin cells in a petri dish, the new screening method would provide a more accurate test of how the potential skin product would interact with living tissue.Professor Vitaliy Khutoryanskiy, a Professor of Formulation Science at the University of Reading said:"Developing more ethical alternatives to tests that others do on rabbits, known as the Draize test, has been a major challenge, especially in relation to evaluating products for sensitive human tissue. Our tests with flatworms show that there are potential ways to screen skin irritants in a more ethically responsible way."While the vast majority of cosmetic skin products are no longer tested on animals, it remains critical that new developments for clinical treatments are tested robustly and we hope that we can find solutions that consign the Draize test to history. We also hope to continue planaria research and develop further tests for probe irritation potential of chemicals to other human tissues."A series of tests with the flatworms looked at whether they can be used to screen for products that are irritants to human skin. Two of the methods, which involved observing the movement of the worms when exposed to known irritants and measuring acute toxicity were not useful.However, there was a positive result in tests which used the common fluorescent dye alongside short-term and low concentration exposure to various chemicals. The planaria which were exposed to known human skin irritants had significant levels of the fluorescent dye under their skin.Planaria are a freshwater-living flatworms which are already widely used in scientific research. They are advanced invertebrates with a primitive brain and share similar features with the vertebrate nervous system found in animals including mammals, examples of the ways that planaria are used include testing the neurotoxicity of potentially hazardous substances. Planaria have a simple but well-characterised epidermal membrane similar to skin that acts as the first point of contact between the worm and a foreign substance.
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Animals
| 2,020 |
September 30, 2020
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https://www.sciencedaily.com/releases/2020/09/200930110131.htm
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Rodent ancestors combined portions of blood and venom genes to make pheromones
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Experts who study animal pheromones have traced the evolutionary origins of genes that allow mice, rats and other rodents to communicate through smell. The discovery is a clear example of how new genes can evolve through the random chance of molecular tinkering and may make identifying new pheromones easier in future studies. The results, representing a genealogy for the exocrine-gland secreting peptide (ESP) gene family, were published by researchers at the University of Tokyo in the journal
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Researchers led by Professor Kazushige Touhara in the University of Tokyo Laboratory of Biological Chemistry previously studied ESP proteins that affect mice's social or sexual behavior when secreted in one mouse's tears or saliva and spread to other animals through social touch.Recently, Project Associate Professor Yoshihito Niimura led a search for the evolutionary origin of ESP genes using the wide variety of fully sequenced animal genomes available in modern DNA databases. Niimura looked for ESP genes in 100 different mammals and found them only in two evolutionarily closely related families of rodents: the Muridae family of mice, rats and gerbils, and the Cricetidae family of hamsters and voles.Notably, the Cricetidae had few ESP genes usually all grouped together in the same stretch of DNA, but the Muridae had both that same small group of ESP genes as well as a second, larger group of additional ESP genes."We can imagine about 35 million years ago, the common ancestor of Muridae and Cricetidae formed the first ESP genes. Eventually, approximately 30 million years ago, the ancestor of Muridae duplicated and expanded these ESP genes. So now mice have many more ESP genes than the Cricetidae rodents," said Niimura.To identify the source of what formed the first ESP gene, researchers compared additional genome sequences. They uncovered how random chance copied uniquely functional portions of two other genes, then coincidentally pasted them next to each other.The DNA sequence of a gene includes portions called exons, which later become the functional protein, and other portions called introns, which do not become protein. Introns and exons are spaced throughout the gene with no apparent organization, introns interrupting essential functional portions of exons. Therefore, if a single exon were randomly copied and pasted elsewhere in the genome, any resulting protein fragment would have no meaningful function.However, if an exon-only version of a gene were copied and reinserted into the genome, the chances of that new sequence remaining functional become much greater. Cells do create exon-only versions of genes called mRNA as part of the normal process of making protein from genes and cells do possess machinery, likely left over from viral infections, that can copy mRNA back into the DNA strand."This is not the normal way of things in cells, but it is a common source of evolution. We guess this is what happened to make ESP genes because the whole functional portion of the ESP gene is one exon, no intron interruption," said Niimura.Specifically, the research team discovered for the first time that ESP proteins contain an uncommon spiral shape characteristic of alpha-globin, a component of the iron-carrying hemoglobin protein in blood. DNA sequence comparisons revealed that multiple alpha-globin gene exons spliced together show a subtle but distinctive similarity to the ESP gene sequence."It doesn't matter that hemoglobin is the source of the ESP pheromone. Any protein can become a pheromone if it is used for species-specific communication," said Niimura.Regardless of its shape, no protein can function without being in the proper location. In ESP proteins, the alpha-globin-derived portion is attached to a signaling portion, which directs the protein to be secreted from salivary and tear glands. Researchers identified the ESP genes' location signaling sequence as resembling that of CRISP2, a gene expressed in mammalian reproductive tracts and salivary glands as well as the venom gland of some snakes.The hemoglobin and CRISP genes are both ancient genes that existed in the shared evolutionary ancestor of vertebrates -- all animals with a backbone -- over 500 million years ago. The genetic shuffling that created ESP genes occurs relatively frequently in the cells of all organisms, but for these changes to become inherited evolutionary traits, the changes must occur in the sex cells so they can be passed on to future generations."The creation of new genes is not done from scratch, but nature utilizes pre-existing material. Evolution is like a tinkerer, using old things and broken parts to create some new device with a useful function," said Niimura.Niimura and his colleagues plan to use their new understanding of the evolution of this one family of pheromones to direct their search for new pheromones. The short length of many known pheromone genes makes it likely that similar pheromones are overlooked in standard genome searches. They also predict that salivary and tear glands, often overlooked because their small size makes them inconvenient tissues to study, may contain interesting future discoveries.
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Animals
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September 30, 2020
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https://www.sciencedaily.com/releases/2020/09/200930094741.htm
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Wildcats threatened by their domestic cousins
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European wildcats, thought to be extinct 50 or so years ago in the Jura mountains, have since recolonised part of their former territory. This resurgence in an area occupied by domestic cats has gone hand-in-hand with genetic crosses between the two species. The hybridisation between wild and domesticated organisms is known to endanger the gene pool of wild species. In a study to be published in the journal
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Although the European wildcat (Felis silvestris) or forest cat was once very common, it fell victim to intensive hunting in the 19th and 20th centuries and to the massive deforestation that cut back its natural habitat, resulting in its disappearance in some parts of Europe. In Switzerland, the wildcat was deemed practically extinct, with no trace found for 25 years from 1943 to 1968. Thanks to a federal law that has protected the animal since 1962, the wildcat has recolonised the forests and meadows in the Jura range, where it lives side-by-side with the domestic cat (Felis catus) in particular. Although considered two species -- or as different subspecies by some -- wildcats and domestic cats can interbreed and have hybrid, fertile kittens. These have the genome of both species and may give birth to offspring carrying the recombinant genes of each species. These hybridisations pose a new threat to the wildcat, since they prompt gene transfers based on a mechanism known as genetic introgression. This mechanism can quickly result in the dissemination of the genes of the more abundant species in the genome of the rarer species. The risk exists in the short term that the genome of the domestic cat will gradually replace the gene of the wildcat, which is markedly less plentiful than its domestic cousin, leading to the extinction of the wildcat.Scientists from UNIGE and the University of Zurich demonstrated in earlier studies that there is a greater introgression of the wildcat genome by the domestic cat genes than vice versa. The demographic and territorial expansion of wildcats over the last 50 years was identified as the most likely cause of these introgressions, which tallies with observations in the field. This conclusion was reached using bioinformatic simulation models factoring in ecological and genetic characteristics. It was estimated that about 5-10% of contacts between wild and domestic cats produced hybrid kittens. Following these discoveries, the computer model was refined in order to make projections and define the urgency for intervening and preserving the species.The variable factors in the model incorporated in the new article, whose last author is Mathias Currat, senior researcher at the UNIGE Department of Genetics and Evolution, are the hybridisation rate, competition for resources in the environment and the size of the populations. Irrespective of the scenario put forward while acting on these variables, a very strong introgression of the domestic cat's genome into the genome of the wildcat is predicted. Mathias sounds a warning: "This is strongest with population sizes comparable to today's, but is still very high even if we consider more favourable conditions for the wildcat, such as an increase in its population size or a competitive advantage over the domestic cat in the regions where they coexist." Juan Montoya-Burgos, laboratory director in the Department of Genetics and Evolution at UNIGE, and co-author of the study, warns: "The model leads to an irreversible genetic replacement resulting in the ultimate disappearance of the wildcat. Only the end of crossbreeding between the two species predicts the conservation of the wild species."It follows that the wildcat remains an endangered species in spite of the positive signs of its recent expansion. The dynamic model put forward in the UNIGE study, which combines the demographic and spatial growth of the wildcat populations, can be used to predict the future of the species. Based on the various scenarios, wildcats will be assimilated to domestic cats in as little as 200 to 300 years, as is already the case in Scotland and Hungary. "A hybridisation event has a proportionally much greater impact on the wildcat population, which consists of a few hundred individuals, than in the domestic population, which numbers over one million individuals in Switzerland," points out Mathias Currat.One initiative suggested by the authors is to drastically reduce the opportunities for hybridisation on the fringes of the wildcat territories. Campaigns to sterilise domestic cats living near farms or close to forests are just one of the proposals. Females should be the primary target since domestic females mate more readily with male wildcats than male domestic cats with wild females. "Early interventions are likely to be less costly both financially and in environmental terms. If we stay passive, the threat to weigh on wildcats in the Jura risks being irreversible," concludes Juan Montoya-Burgos.
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Animals
| 2,020 |
September 30, 2020
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https://www.sciencedaily.com/releases/2020/09/200930085208.htm
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Mosquitoes lost an essential gene with no ill effects
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University of Maryland entomologists discovered that a gene critical for survival in other insects is missing in mosquitoes -- the gene responsible for properly arranging the insects' segmented bodies. The researchers also found that a related gene evolved to take over the missing gene's job. Although laboratory studies have shown that similar genes can be engineered to substitute for one another, this is the first time that scientists identified a gene that naturally evolved to perform the same critical function as a related gene long after the two genes diverged down different evolutionary paths.
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The work emphasizes the importance of caution in genetic studies that use model animals to make conclusions across different species. It also points to a new potential avenue for research into highly targeted mosquito control strategies. The research study was published in the September 30, 2020, issue of the journal "Every single arthropod has a segmented body plan. And you would think it develops the same way in all of them. But what we found is that it doesn't," said Alys Jarvela, a postdoctoral associate in the UMD Department of Entomology and the lead author of the study. "We learn a lot in biology by studying a process in a model organism and assuming that it works essentially the same way, using the same genes, in other organisms. That is still an incredibly useful approach. But, now we know that there is also a possibility for gene substitutions to be made in nature."Jarvela discovered the missing gene in mosquitoes by accident. She was studying crickets and attempting to cross-check her genetic samples by comparing the gene sequences of crickets with those of other insects. She was specifically interested in a gene called paired, one of a handful of genes that guides the pattern of repeated parts in segmented animals like insects. Laboratory studies had shown that when paired is knocked out or silenced in fruit flies, every other segment of the insect's body fails to develop, and it doesn't survive."I was just trying to find the mosquito version of paired to use as a reference point, and I couldn't find, it," Jarvela said.When she searched for paired in all publicly available databases of mosquito genomes, she discovered it was missing from every mosquito species represented. "Once we accepted that the gene was really absent, we thought that was a pretty wild mystery and immediately changed gears to satisfy our curiosity," Jarvela said.Jarvela's team searched the genomes of fly species closely related to mosquitoes and found they all contained the paired gene. This indicated that the loss of paired is a recent evolutionary event that took place only in mosquitoes. It was clear to the researchers that some other gene in mosquitoes must be performing the same function as paired does in other insects.They found clues suggesting which gene could be involved in a 1996 experiment on fruit flies. In that study, scientists knocked out paired and replaced it with a closely related gene called gooseberry, which normally has a distinct role at a later time in development. That was a highly engineered experiment, but it showed that when gooseberry was manipulated to express at the right time during development, fruit flies without the paired gene developed normal alternating segments and survived.To find out if gooseberry had naturally evolved as a substitute for paired in mosquitoes, Jarvela and her team used CRISPR to edit gooseberry out of a mosquito species called Anopheles stephensi. The mutated mosquito embryos looked like laboratory fruit fly embryos that had paired knocked out."This work shows that even when different species share a trait or feature, the genetic mechanisms underlying this shared trait may be different," said Leslie Pick, professor and chair of the Department of Entomology at UMD and the study's senior author. "In the case reported in this paper, segmentation still happens even though a gene we thought was essential is lost. Our next steps will be to search for additional examples of variation in gene regulatory networks in insects and try to determine how genetic rewiring occurs in nature."Jarvela is also interested in probing other aspects of mosquito development that may be affected by the loss of the paired gene. In addition to controlling segmentation, which is critical for survival, paired influences male fertility in fruit flies."That means different genes probably regulate male fertility in mosquitoes, and they might be unique to the mosquito, which could potentially provide a powerful avenue for controlling mosquitoes without harming other insects such as butterflies and bees," Jarvela said.
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Animals
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September 30, 2020
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https://www.sciencedaily.com/releases/2020/09/200930085206.htm
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New study reveals how reptiles divided up the spoils in ancient seas
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While dinosaurs ruled the land in the Mesozoic, the oceans were filled by predators such as crocodiles and giant lizards, but also entirely extinct groups such as ichthyosaurs and plesiosaurs.
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Now for the first time, researchers at the University of Bristol have modelled the changing ecologies of these great sea dragons.Mesozoic oceans were unique in hosting diverse groups of fossil reptiles, many of them over 10 metres long.These toothy monsters fed on a variety of fishes, molluscs, and even on each other. Yet most had disappeared by the end of the Cretaceous, 66 million years ago, when the dinosaurs also died out. There are still some marine crocodiles, snakes and turtles today, but sharks, seals, and whales took over these ecological roles.In a new study, completed when she was studying for the MSc in Palaeobiology at the University of Bristol's School of Earth Sciences, Jane Reeves, now a PhD student at the University of Manchester, used modern computational methods to explore how all these marine reptiles divided up the spoils.Jane said: "It's difficult to work out the ecology and function of fossil animals but we decided to focus mainly on their feeding and swimming styles. I tracked down information on 371 of the best-known Mesozoic marine tetrapods, and coded each one for 35 ecological traits, including body size, diet, likely hunting style, tooth type, presence or absence of armour, limb shape and habitat."The numerical analysis showed that all these marine reptiles could be divided into just six ecological categories linking how they moved, where they lived, and how they fed: pursuit predators that chased their prey, ambush predators that lurked and waited for the prey to swim past (two groups, one in deep water, one in shallow), a fourth group of reptiles that could still walk on land, shallow-water shell-crushers and foragers, and marine turtles with a variety of life modes.Professor Mike Benton, who co-supervised the study, said: "A problem with studies of form and function of fossils is that we have to be careful in reconstructing the behaviour of ancient animals. But in Jane's study, she used ecological characters from the start where their function had already been established. For example, sharp pointy teeth mean fish-eating, whereas broad, flat teeth mean shell crushing."Dr Ben Moon, another co-supervisor, said: "We knew that the different marine reptile groups came and went through the 186 million years of the Mesozoic."I'm especially interested in ichthyosaurs, and we wanted to test an idea that they had migrated through ecospace during the Mesozoic. Jane's study shows definite movement through time from being semi-terrestrial at the beginning of the Triassic to a wide range of ecologies, including ambush hunting, and finally pursuit predation in the Jurassic and Cretaceous."Dr Tom Stubbs, another co-supervisor, said: "We also wanted to test whether all these animals were competing with each other. But in fact, they seem to have avoided competition."For example, after a substantial extinction of marine reptiles around the end of the Triassic, the surviving ichthyosaurs and plesiosaurs showed considerable conservatism. They didn't expand their ecological roles at all, and many niches were left empty until new groups of crocodiles and turtles emerged later in the Jurassic to take over these roles."Jane Reeves added: "It was a great experience being able to study a large variety of creatures, and to then reconstruct the ecological lifestyles of extinct animals from just their fossils."You do have to be very careful in doing these kinds of studies, not to make any unfounded assumptions. We know animals can be opportunistic, and don't always behave exactly how we think they should, but we're confident that the data we collected reflects the most common, day-to-day, behaviours of each animal. These results give us a great insight into what was really happening under the surface of the Mesozoic seas."This research was part funded by the Natural Environment Research Council (NERC) and the European Research Council (ERC).
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Animals
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September 30, 2020
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https://www.sciencedaily.com/releases/2020/09/200930085155.htm
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Predator-prey interaction study reveals more food does not always mean more consumption
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Scientists at the NOAA Northeast Fisheries Science Center have developed an unusually rich picture of who is eating whom off the Northeastern United States. The findings, published recently in
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The predators are divided into 48 predator-size categories, and 14 prey species. Fish predators included Atlantic cod, Atlantic herring, haddock, goosefish, pollock, spiny dogfish, winter flounder, and yellowtail founder among others. Prey species included forage fish, squid, zooplankton, shrimp-like crustaceans, shellfish, brittle stars, sand dollars, and sea urchins."We have the largest, continuous dataset of fish feeding habits in the world at the Northeast Fisheries Science Center, and that enabled us to do a study of this scale and scope," said Brian Smith, a food habits researcher at the center and lead author of the study. "We focused on common and important prey for the many predatory fishes of interest, and hopefully filled in some gaps in information relating prey availability to predation."Feeding patterns within and among different groups of fishes vary by the size of the fish, the abundance or density of the prey, and other factors. Researchers who study marine ecosystems need to account for this predation in their models. Few studies, however, have looked simultaneously at the feeding patterns among different groups of predatory fish -- fish feeders, plankton feeders, and benthic or bottom feeders. The study also looked at how those groups interact with their prey throughout the water column.Smith and co-author Laurel Smith tested three models using decades of fisheries data that included diet and prey density. The data were collected on the Northeast U.S. Continental Shelf during benthic surveys in the 1950s and 1960s, and during ecosystem sampling surveys beginning in 1973. For this study, the data were used to gain insight into:Among the study findings: most of the fish responded to changing abundance of prey by switching prey, or through a "learning period" when the prey in highest abundance was targeted. That response helps stabilize prey populations, and was prevalent among piscivores (fish eaters). It was often observed for predators with less-specialized feeding habits. Those predators included goosefish and larger sizes of other well-known commercial fishes.High densities of invertebrate prey, however, revealed decreased feeding by fish that were planktivores and benthivores -- plankton and bottom feeders. For these fish, more food did not translate to more consumption. Researchers found that denser prey may disorient or confuse the planktivores, reducing their feeding on zookplankton. The planktivores include Atlantic herring, Atlantic mackerel, and smaller sizes of pollock, silver hake, spiny dogfish and white hake. Their feeding response is not often considered in studies of marine ecosystems.The benthivores studied included smaller sizes of Atlantic cod, red hake, and winter skate, and all sizes of haddock, ocean pout, and several flounders and a few other species. These fish ate small benthic invertebrates as small and medium-sized fish. Larger individuals of those same species, however, ate mostly fish and had a different predator-prey relationship.The study findings provide insight into predation on and by commercial fishery species throughout the water column. This will help with ecosystem modeling since predation needs to be accounted for as competition, or as a direct removal of commercially and ecologically important prey species. Refining the model inputs can also increase our understanding of continental shelf ecology, and improve decision-making for ecosystem-based fisheries management.
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September 29, 2020
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https://www.sciencedaily.com/releases/2020/09/200929152154.htm
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Genomes of two millipede species shed light on their evolution, development and physiology
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Millipedes, those many-legged denizens of the soil surface throughout the world, don't always get the recognition they deserve. But a new study by Jerome Hui of Chinese University of Hong Kong and colleagues puts them in the spotlight, sequencing and analyzing complete genomes from two very different millipede species. The study, publishing on September 29th in the open-access journal
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Millipedes and centipedes together comprise the Myriapoda -- arthropods with multi-segmented trunks and many legs. Centipedes sport one pair of legs per segment, while millipedes bear two. Despite the apparent numeric implications of their names, different centipede species bear between 30 and 354 legs, and millipedes between 22 and 750. There are about 16,000 species of myriapods, including over 12,000 species of millipedes, but only two myriapod genomes have so far been characterized; a complete genome for the centipede Strigamia maritima, and a rough "draft" sequence of a millipede genome.The authors of the new study fully sequenced the genomes of two millipede species, the orange rosary millipede The researchers found that two species have genomes of vastly different sizes -- the orange rosary's genome is 182 million base pairs (Mb), while the rusty's is 449 Mb -- which the authors showed was due mainly to the rusty millipede's genome containing larger non-coding regions (introns) within genes and larger numbers of repetitive "junk" DNA sequences.Homeobox genes play central roles in body plan formation and segmentation during animal development, and the authors found lineage-specific duplications of common homeobox genes in their two species, which differed as well from those found in the previously published millipede genome. None of the three, however, displayed the massive duplications seen in the homeobox genes in the centipede genome. They made further discoveries about the organization and regulation of the homeobox genes as well.Many millipedes bear characteristic glands on each segment, called ozadene glands, which synthesize, store, and secrete a variety of toxic and noxious defensive chemicals. The authors identified multiple genes involved in production of these chemicals, including genes for synthesizing cyanide, as well as antibacterial, antifungal, and antiviral compounds, supporting the hypothesis that ozadene gland secretions protect against microbes as well as predators.The results of this study provide new insights into evolution of the myriapods, and arthropods in general. "The genomic resources we have developed expand the known gene repertoire of myriapods and provide a genetic toolkit for further understanding of their unique adaptations and evolutionary pathways," Hui said.
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Animals
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September 29, 2020
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https://www.sciencedaily.com/releases/2020/09/200929130259.htm
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Vessel noise present year-round at Cordell Bank National Marine Sanctuary
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The environment in the Cordell Bank National Marine Sanctuary off the coast of San Francisco is not a refuge from the noise generated by ship traffic, the first underwater marine acoustic study of the region has shown.
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Vessel and other human sound is not currently regulated in Cordell Bank National Marine Sanctuary, but sanctuary officials are trying to learn more about its impact on animals as part of efforts to evaluate and improve the management of the ecosystem.Noise from human activity such as vessel traffic or offshore drilling can have an impact on the health of marine animals. For example, whales rely on sound to forage, communicate, navigate and avoid predators -- processes that can be hindered by human-made noise."Noise levels we measured at some frequencies in the sanctuary were higher than those modeled for the Channel Islands National Marine Sanctuary near the Port of Los Angeles, which is considered the largest port in U.S. waters," said Samara Haver, a doctoral candidate in the College of Agricultural Sciences at Oregon State University and the study's lead author."That says a lot about the vessel activity going on around and in the Cordell Bank National Marine Sanctuary and how it is affecting the immediate environments."The sanctuary's small size, close proximity to dense shipping lanes and exposure to deep-ocean areas where sound may travel farther could contribute to the sound environment, researchers said. The national marine sanctuary system has identified ocean noise as a priority issue.Findings from the sound study were published recently in the Cordell Bank National Marine Sanctuary is located off the coast of northern California, with its southern-most boundary about 42 miles north of San Francisco. The sanctuary encompasses nearly 1,300 square miles. It is an extremely productive marine area centered on Cordell Bank, a rocky undersea feature several miles long and wide that sits at the edge of the continental shelf.Cordell Bank is one of five national marine sanctuaries in the Pacific along the West Coast of the United States and one of three off the northern California coast near San Francisco.Sanctuary regulations are designed to protect the integrity of the ecosystem. Ships are permitted to transit through the sanctuary but disturbing the seafloor and discharging material into the sanctuary are generally prohibited. Most large ships travel within what's known as a "traffic separation scheme" -- a highly-regulated shipping route system. Cordell Bank and the nearby Greater Farallones National Marine Sanctuary also request voluntary shipping slowdowns from May 1 to Nov. 15 to protect aggregations of whales."One of the sanctuary's primary needs is to document the soundscape and to begin to understand how animals in the sanctuary may be affected by human-made sounds," said Danielle Lipski, research coordinator at Cordell Bank National Marine Sanctuary. "This is an innovative way for us to learn new information about whales in the sanctuary using methods that complement the visual survey work we do."In October 2015, researchers deployed a long-term continuous underwater acoustic monitor in the sanctuary and recorded ambient sound for two years. Passive acoustic sound monitoring offers a low-impact, cost effective way to monitor the health of the marine environment and the effectiveness of marine conservation efforts."This initial study helps us establish a baseline to start understanding what is going on in that environment," said Haver, who studies marine acoustics and works out of the Cooperative Institute for Marine Resources Studies, a partnership between OSU and NOAA at Hatfield Marine Science Center in Newport.Among the researchers' findings:Understanding patterns of whale presence in the sanctuary environment is helpful for sanctuary managers. Data collected from the acoustic study can be used to inform management efforts such as speed reduction programs during peak periods for whales that could reduce ship strikes and whale entanglements, Haver said."When whales or other marine species are not surfacing, we cannot see them," Haver said, "Acoustic monitoring gives us a way to track their movements when otherwise it would be impossible. We can supplement and verify visual data and that gathered through whale tagging."Haver also compared the sound levels at Cordell Bank National Marine Sanctuary to past research that modeled noise levels in the Channel Islands National Marine Sanctuary, which is near the Port of Los Angeles and high-traffic West Coast shipping lanes and found Cordell Bank to be noisier at some frequencies. Researchers also have measured noise levels in Channel Islands and other sanctuaries and plan to do additional noise comparisons in future work.Scientists also are continuing to monitor sound in Cordell Bank and in the future will be able to compare data from different time periods to see what changes may be occurring in the marine environment. Researchers in the future hope to analyze changes in the marine environment as the COVID-19 pandemic set in and ship traffic was reduced, Dziak said.Additionally, the initial monitoring only captured low-frequency sound; recording higher frequency sound in the future would likely capture vocalizations of other whale species and may give scientists additional insight into the marine acoustic environment of the region. Acoustic monitoring is also underway at other sanctuaries including Monterey Bay National Marine Sanctuary and Channel Islands National Marine Sanctuary off the coast of California; Olympic Coast National Marine Sanctuary off the coast of Washington; and Stellwagen Bank National Marine Sanctuary off the coast of Massachusetts.
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September 28, 2020
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https://www.sciencedaily.com/releases/2020/09/200928093740.htm
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Salute the venerable ensign wasp, killing cockroaches for 25 million years
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An Oregon State University study has identified four new species of parasitic, cockroach-killing ensign wasps that became encased in tree resin 25 million years ago and were preserved as the resin fossilized into amber.
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"Some species of ensign wasps have even been used to control cockroaches in buildings," OSU researcher George Poinar Jr. said. "The wasps sometimes are called the harbingers of cockroaches -- if you see ensign wasps you know there are at least a few cockroaches around. Our study shows these wasps were around some 20 or 30 million years ago, with probably the same behavioral patterns regarding cockroaches."Ensign wasps, of the Hymenoptera order and scientifically known as Evaniidae, earned their common name because their abdomen resembles a flag; an ensign is a large flag on a ship, usually flown at the stern or rear of the vessel, that indicates the ship's nationality."As the wasps move about, their 'ensign' is constantly moving up and down as if they are flag waving," said Poinar, professor emeritus in the OSU College of Science and an international expert in using plant and animal life forms trapped in amber to learn more about the biology and ecology of the distant past.About 400 species of ensign wasps exist today, distributed across 20 genera. The wasps live everywhere except polar regions. They typically measure 5 to 7 millimeters in length and don't sting or bite but are lethal for unhatched cockroaches.A female ensign wasp will look for cockroach egg cases, known as ootheca, and lay an egg on or in one of the cockroach eggs inside the case. When the wasp egg hatches, the larva eats the cockroach egg where it was laid.Successive instars of the larva then consume the other dozen or so eggs inside the cockroach egg case. Mature wasp larvae pupate within the cockroach egg case en route to coming out as adults, and no cockroach offspring emerge from an egg case infiltrated by an ensign wasp.Analyzing Tertiary period specimens from Dominican amber, Poinar was able to describe three new species of ensign wasps: Evaniella setifera, Evaniella dominicana and Semaeomyia hispaniola. He described a fourth, Hyptia mexicana, from Mexican amber. The Tertiary period began 65 million years ago and lasted for more than 63 million years.No cockroaches accompanied the wasps in the amber, but three flying termites were found along with an ensign wasp in one of the Dominican amber pieces. It's likely the termites were sharing a nest with the cockroaches and this attracted the wasp, Poinar said.
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Animals
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September 26, 2020
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https://www.sciencedaily.com/releases/2020/09/200926145210.htm
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Pets linked to maintaining better mental health and reducing loneliness during lockdown, new research shows
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Sharing a home with a pet appeared to act as a buffer against psychological stress during lockdown, a new survey shows.
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Most people who took part in the research perceived their pets to be a source of considerable support during the lockdown period (23 March -- 1 June, 2020).The study -- from the University of York and the University of Lincoln -- found that having a pet was linked to maintaining better mental health and reducing loneliness. Around 90 per cent of the 6,000 participants who were from the UK had at least one pet. The strength of the human-animal bond did not differ significantly between species with the most common pets being cats and dogs followed by small mammals and fish.More than 90 per cent of respondents said their pet helped them cope emotionally with the lockdown and 96 per cent said their pet helped keep them fit and active.However, 68 per cent of pet owners reported having been worried about their animals during lockdown, for example due to restrictions on access to veterinary care and exercise or because they wouldn't know who would look after their pet if they fell ill.Lead author, Dr Elena Ratschen from the Department of Health Sciences University of York said: "Findings from this study also demonstrated potential links between people's mental health and the emotional bonds they form with their pets: measures of the strength of the human-animal bond were higher among people who reported lower scores for mental health-related outcomes at baseline."We also discovered that in this study, the strength of the emotional bond with pets did not statistically differ by animal species, meaning that people in our sample felt on average as emotionally close to, for example, their guinea pig as they felt to their dog."It will be important to ensure that pet owners are appropriately supported in caring for their pet during the pandemic."Co-author, Professor Daniel Mills from the School of Life Sciences at the University of Lincoln said: "This work is particularly important at the current time as it indicates how having a companion animal in your home can buffer against some of the psychological stress associated with lockdown. However, it is important that everyone appreciates their pet's needs too, as our other work shows failing to meet these can have a detrimental effect for both people and their pets."Dr Ratschen added: "While our study showed that having a pet may mitigate some of the detrimental psychological effects of the Covid-19 lockdown, it is important to understand that this finding is unlikely to be of clinical significance and does not warrant any suggestion that people should acquire pets to protect their mental health during the pandemic."More than 40% of UK households are estimated to own at least one pet.The study also showed that the most popular interaction with animals that were not pets was birdwatching. Almost 55 per cent of people surveyed reported watching and feeding birds in their garden.The paper, "Human-animal relationships and interactions during the Covid-19 lockdown phase in the UK: investigating links with mental health and loneliness" is published in the journal
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Animals
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September 26, 2020
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https://www.sciencedaily.com/releases/2020/09/200926145207.htm
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Bird genes are multitaskers, say scientists
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Scientists from the University of Sheffield have found that although male and female birds have an almost identical set of genes, they function differently in each sex through a mechanism called alternative splicing.
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Males and females of the same bird species can be strikingly different. For example, in addition to fundamental differences in reproduction, the sexes can show profound variation in behavior, colouration, metabolism, disease incidence and life history. The team wanted to understand how these remarkable differences develop despite males and females sharing mostly the same DNA.Thea Rogers, PhD student at the University of Sheffield and lead author of the study, said: "One notable example of differences between male and female birds is in the peafowl, peacocks have magnificent plumage, whereas the female peahen is relatively dull. The peacock's long tail and bright colours evolved to help them attract mates, but having such eye-catching looks can come with negatives such as making them more noticeable to predators."Features like this are beneficial to the males but may not be beneficial for females, so birds must find a way to evolve different characteristics. We predicted that the secret to these differences must lie in understanding how the same genes are expressed and function differently in males and females."The team studied the genomes of multiple bird species to understand how they expressed these different qualities in males and females.Genes encode proteins, large complex molecules which drive processes in the body and are responsible for the function and structure of the body's tissues. Before genes can be used to make proteins, their DNA sequence is transcribed into RNA, an intermediary molecule that contains the instructions for making proteins.The scientists found that males and females differ in how bits of RNA are stitched together, meaning that the same gene can produce a large number of distinct proteins and functions depending on which sex the gene is expressed in. This process is called alternative splicing.Dr Alison Wright, a researcher at the University of Sheffield and senior author of the study, said: "It is likely that this genetic process is really important for generating biodiversity, not only in birds but across the whole animal kingdom."The study, published in
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Animals
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September 24, 2020
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https://www.sciencedaily.com/releases/2020/09/200924114130.htm
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Penicillium camemberti: A history of domestication on cheese
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The white, fluffy layer that covers Camembert is made of a mould resulting from human selection, similar to the way dogs were domesticated from wolves. A collaboration involving French scientists from the CNRS* has shown, through genomic analyses and laboratory experiments, that the mould Penicillium camemberti is the result of a domestication process that took place in several stages.
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According to their work, a first domestication event resulted in the blue-green mould P. biforme, which is used, for example, for making fresh goat's cheese. A second, more recent domestication event resulted in the white and fluffy P. camemberti.Both domesticated species show advantageous characteristics for maturing cheese compared to the wild, closely related species: they are whiter and grow faster in cheese-ripening cellar conditions. In addition, they do not produce, or only in very small quantities, a toxin that is potentially dangerous to humans; they also prevent the proliferation of undesirable moulds.This research, published on 24th September in * The study involved scientists from the Ecology, Systematics and Evolution laboratory (CNRS/Université Paris-Saclay/AgroParisTech) and the Biodiversity and Microbial Ecology laboratory (Université de Brest, Plouzané).
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Animals
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September 24, 2020
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https://www.sciencedaily.com/releases/2020/09/200924101932.htm
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Camera traps show impact of recreational activity on wildlife
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The COVID-19 pandemic has fired up interest in outdoor activities in our parks and forests. Now a new UBC study highlights the need to be mindful of how these activities may affect wildlife living in protected areas.
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Researchers placed motion-activated cameras on the trails in and around the South Chilcotin Mountains Provincial Park in southwestern B.C., a region popular for its wildlife and recreational activities such as hiking, horseback riding, ATV riding and mountain biking. Overall, they found that environmental factors -- like the elevation or the condition of the forest around a camera location -- were generally more important than human activity in determining how often wildlife used the trails.However, there were still significant impacts. Deeper analysis of trail use captured by the cameras showed that all wildlife tended to avoid places that were recently visited by recreational users. And they avoided mountain bikers and motorized vehicles significantly more than they did hikers and horseback riders.The researchers focused on 13 species including grizzly bear, black bear, moose, mule deer and wolf."We wanted to better understand the relative impacts of human recreation in this region, given its increasing popularity. We already know that motorized vehicle access can disrupt wildlife; our initial findings suggest that other types of recreation may also be having impacts," said study author Robin Naidoo, a UBC adjunct professor at the Institute for Resources, Environment and Sustainability.Like many parks, the South Chilcotin Mountains provincial park and nearby regions are experiencing growing pressure from human activities -- both recreational and industrial. According to Naidoo, the study confirms that camera traps can effectively monitor both wildlife and human trail use in these and other remote regions. "We'll be able to collect more information over time and build a solid basis for research findings that can ultimately inform public policy," he added"Study co-author Cole Burton, a professor of forestry at UBC and the Canada Research Chair in terrestrial mammal conservation, says further research will be needed before any firm conclusions can be drawn."This is the first year of our multiyear study of the region. We'll continue to observe and to analyze, so that we can better understand and mitigate the effects of these different human activities on wildlife," said Burton. "Outdoor recreation and sustainable use of forest landscapes are important, but we need to balance them with potential disruption of the ecosystem and the loss of important species.""Relative effects of recreational activities on a temperate terrestrial wildlife assemblage" was published recently in
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Animals
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September 24, 2020
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https://www.sciencedaily.com/releases/2020/09/200924101925.htm
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Scientists discover why tarantulas come in vivid blues and greens
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Why are some tarantulas so vividly coloured? Scientists have puzzled over why these large, hairy spiders, active primarily during the evening and at night-time, would sport such vibrant blue and green colouration -- especially as they were long thought to be unable to differentiate between colours, let alone possess true colour vision.
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In a recent study, researchers from Yale-NUS College and Carnegie Mellon University (CMU) find support for new hypotheses: that these vibrant blue colours may be used to communicate between potential mates, while green colouration confers the ability to conceal among foliage. Their research also suggests that tarantulas are not as colour-blind as previously believed, and that these arachnids may be able to perceive the bright blue tones on their bodies. The study was published in The research was jointly led by Dr Saoirse Foley from CMU, and Dr Vinod Kumar Saranathan, in collaboration with Dr William Piel, both from the Division of Science at Yale-NUS College. To understand the evolutionary basis of tarantula colouration, they surveyed the bodily expression of various opsins (light-sensitive proteins usually found in animal eyes) in tarantulas. They found, contrary to current assumptions, that most tarantulas have nearly an entire complement of opsins that are normally expressed in day-active spiders with good colour vision, such as the Peacock Spider.These findings suggest that tarantulas, long thought to be colour-blind, can perceive the bright blue colours of other tarantulas. Using comparative phylogenetic analyses, the team reconstructed the colours of 110 million-year-old tarantula ancestors and found that they were most likely blue. They further found that blue colouration does not correlate with the ability to urticate or stridulate -- both common defence mechanisms -- suggesting that it did not evolve as a means of deterring predators, but might instead be a means of attracting potential mates.The team also found that the evolution of green colouration appears to depend on whether the species in question is arboreal (tree-dwelling), suggesting that this colour likely functions in camouflage."While the precise function of blueness remains unclear, our results suggest that tarantulas may be able to see these blue displays, so mate choice is a likely potential explanation. We have set an impetus for future projects to include a behavioural element to fully explore these hypotheses, and it is very exciting to consider how further studies will build upon our results," said Dr Foley.The team's survey of the presence of blue and green colouration across tarantulas turned up more interesting results. They found that the blue colouration has been lost more frequently than it is gained across tarantulas. The losses are mainly in species living in the Americas and Oceania, while many of the gains are in the Old World (European, Asian, and African) species. They also found that green colouration has evolved only a few times, but never lost."Our finding that blueness was lost multiple times in the New World, while regained in the Old, is very intriguing. This leaves several fascinating avenues for future research, when considering how the ecological pressures in the New and the Old Worlds vary," said Dr Saranathan. "For instance, one hypothesis would be differences in the light environments of the habitats between the New and the Old World, which can affect how these colours might be perceived, if indeed they can be, as our results suggest."
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Animals
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September 23, 2020
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https://www.sciencedaily.com/releases/2020/09/200923090424.htm
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Jaws of death: Paleontologist renames giant, prehistoric marine lizard
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Some 92 to 66 million years ago, as the Age of Dinosaurs waned, giant marine lizards called mosasaurs roamed an ocean that covered North America from Utah to Missouri and Texas to the Yukon. The air-breathing predators were streamlined swimmers that devoured almost everything in their path, including fish, turtles, clams and even smaller mosasaurs.
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Coloradoan Gary Thompson discovered mosasaur bones near the Delta County town of Cedaredge in 1975, which the teen reported to his high school science teacher. The specimens made their way to Utah's Brigham Young University, where, in 1999, the creature that left the fossils was named Prognathodon stadtmani."I first learned of this discovery while doing background research for my Ph.D.," says newly arrived Utah State University Eastern paleontologist Joshua Lively, who recently took the reins as curator of the Price campus' Prehistoric Museum. "Ultimately, parts of this fossil, which were prepared since the original description in 1999, were important enough to become a chapter in my 2019 doctoral dissertation."Upon detailed research of the mosasaur's skeleton and a phylogenetic analysis, Lively determined the BYU specimen is not closely related to other species of the genus Prognathodon and needed to be renamed. He reclassified the mosasaur as Gnathomortis stadtmani and reports his findings in the most recent issue of the His research was funded by the Geological Society of America, the Evolving Earth Foundation, the Texas Academy of Science and the Jackson School of Geosciences at The University of Texas at Austin."The new name is derived from Greek and Latin words for 'jaws of death,'" Lively says. "It was inspired by the incredibly large jaws of this specimen, which measure four feet (1.2 meters) in length."An interesting feature of Gnathomortis' mandibles, he says, is a large depression on their outer surface, similar to that seen in modern lizards, such as the Collared Lizard. The feature is indicative of large jaw muscles that equipped the marine reptile with a formidable biteforce."What sets this animal apart from other mosasaurs are features of the quadrate -- a bone in the jaw joint that also forms a portion of the ear canal," says Lively, who returned to the fossil's Colorado discovery site and determined the age interval of rock, in which the specimen was preserved."In Gnathomortis, this bone exhibits a suite of characteristics that are transitional from earlier mosasaurs, like Clidastes, and later mosasaurs, like Prognathodon. We now know Gnathomortis swam in the seas of Colorado between 79 and 81 million years ago, or at least 3.5 million years before any species of Prognathodon."He says fossil enthusiasts can view Gnathomortis' big bite at the BYU Museum of Paleontology in Provo, Utah, and see a cast of the skull at the Pioneer Town Museum in Cedaredge, Colorado. Reconstructions of the full skeleton are on display at the John Wesley Powell River History Museum in Green River, Utah, and in BYU's Eyring Science Center."I'm excited to share this story, which represents years of effort by many citizen scientists and scholars, as I kick off my new position at USU Eastern's Prehistoric Museum," Lively says. "It's a reminder of the power of curiosity and exploration by people of all ages and backgrounds."
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Animals
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September 23, 2020
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https://www.sciencedaily.com/releases/2020/09/200916094237.htm
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Tail regeneration in lungfish provides insight into evolution of limb regrowth
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For most vertebrates, losing a limb is permanent, but a lucky few species -- such as salamanders and tadpoles -- have the ability to completely regrow complex body parts. Understanding the molecular mechanisms underlying this phenomenon may be the key to developing new kinds of regenerative medicine, giving us the power to heal spinal cord injuries and other severely damaged tissues.
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A new study published in the The inspiration for this research grew out of a postdoctoral fellowship in the Shubin Lab at UChicago. After completing his postdoctoral studies in evolutionary biology, Igor Schneider, PhD, accepted a faculty position in Belém, Brazil, where he found the diversity of the Amazon rainforest at his fingertips. He became interested in exploring evolutionary traits in new animal models and ultimately narrowed his focus to regenerative biology. He began exploring mechanisms of regeneration in the lungfish -- first in South American species, and then in West African lungfish."When we're talking about how a salamander regrows a lost tail, we're talking about regrowing all sorts of tissues," said Schneider, an Associate Professor of Biological Sciences at the Universidade Federal do Pará and a Visiting Associate Professor of Organismal Biology at UChicago. "Vertebrae, spinal cord, muscle, it's a very complex structure. Mammals, birds and most reptiles can't regenerate tissue like that, but salamanders can. We know some of the biology of how that happens, but we don't really know much about how it evolved, or when. Did our ancestors have the ability to regenerate a lost limb? Did we lose this capacity as mammals, or did salamanders get lucky enough to invent it later on?"One way to answer this question is to determine whether or not the trait existed in the common ancestor between humans and salamanders. To do this, the researchers took a phylogenetic approach, looking for additional relatives that possess a similar regenerative trait. Lungfish are unique in that they are "our closest fish cousin," Schneider said. "They can regenerate their tails, but they are also our closest relative in the water. This lets us explore whether or not this regenerative ability was also likely to be present in our common ancestor, without having to go too deep into our phylogenetic tree."Lungfish represent an ideal model for more reasons than one. "These animals have the right anatomy to study this question and can also be easily managed in the lab," said Neil Shubin, PhD, the Robert R. Bensley Distinguished Service Professor of Organismal Biology and Anatomy at UChicago. "Lungfish are much more closely related to humans than other common species that have regenerative abilities, like zebrafish. For instance, lungfish have a humerus in their fin, just like the bone in our upper arms. They have lungs that are similar to ours. There is a suite of characteristics suggesting that these animals are much more closely related to us than zebrafish."The investigators were initially challenged with establishing the lungfish as a model from the ground up, learning how to care for the fish in a laboratory setting, sampling tissue and obtaining DNA sequencing data to get a clearer picture of the animal's genetics, and testing new antibodies and techniques in a brand-new species.What they found was that the West African lungfish could not only fully regenerate a lost tail, but that the regeneration used similar molecular mechanisms to the limb regrowth seen in amphibians. This includes a critical signaling molecule, Shh, which plays a key role in the growth and organization of the brain and body during embryonic development. This provides support for the hypothesis that this type of regeneration was present in a common ancestor of these species -- and of humans.But perhaps even more interesting than the similarities in regeneration processes are the differences. "What I found particularly intriguing were some of the aspects of tail regrowth that are unique to the lungfish," said Schneider. "These animals are known for having gigantic genomes -- up to 40 times as large as a human's -- because their genomes contain a lot of virus-derived DNA elements, called transposons. During regeneration, some of those genes turn on, but we don't know if it's just because they're close to other key genes in this process, or if it's because these genes are actively involved in regeneration. Some of this has been seen in amphibian regeneration as well, so it begs the question of whether or not these transposons play a particular role in regeneration."In addition to providing insights on the evolutionary origin of this trait, the researchers say this new animal model will help further the field of regenerative medicine. "Often, when you have limited models, you'll try to understand a process very well in a given species, and then extrapolate what you learn to other species," Schneider said. "But you might encounter things that are unique to the species you're studying that won't always apply to other animals. Understanding phenomena like regeneration in a comparative way, looking at how other organisms are doing this, can help us find general themes in regeneration."Further clarifying the evolution of limb regeneration in lungfish and other species, along with their underlying mechanisms, may uncover new treatments for severe wounds, spinal cord injuries and amputations. "Ultimately, we're trying to understand the ancestral tool kit used by these species to conduct the regeneration process," said Shubin. "This will help us figure out what parts of that tool kit we as humans have lost, at the genetic and cellular level, and more importantly, what parts can we recreate?"The study, "Salamander-like tail regeneration in the West African lungfish," was supported by the Brazilian National Council for Scientific and Technological Development Universal Program (Grant 403248/2016-7), the CAPES-Humboldt Foundation Fellowship, CAPES/DAAD PROBRAL (Grant 88881.198758/2018-01), MCTIC/FINEP/FNDCT/AT Amazonia Legal to I.S. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior -- Brasil (CAPES) -- Finance Code 001. Additional authors include Kellen Matos Verissimo, Aline Cutrim Dragalzew, Sylvain Darnet, Wainna Renata Barroso Mendes, Ciro Ariel dos Santos Neves, Erika Monteiro dos Santos, Cassia Nazare de Sousa Moraes, and Josane de Freitas Sousa of the Universidade Federal do Pará; Louise Neiva Pereze of the Universidade Federal do Pará and the Leibniz Institute for Evolution and Biodiversity Science; Nadia Belina Fröbisch of the Leibniz Institute for Evolution and Biodiversity Science; Gayani Senevirathne of the University of Chicago; and Ahmed Elewa of the Karolinska Institute.
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Animals
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September 22, 2020
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https://www.sciencedaily.com/releases/2020/09/200922144323.htm
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Animals lose fear of predators rapidly after they start encountering humans
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Most wild animals show a suite of predator avoidance behaviors such as vigilance, freezing, and fleeing. But these are quickly reduced after the animals come into contact with humans through captivity, domestication, or urbanization, according to a study led by Benjamin Geffroy from MARBEC (Institute of Marine Biodiversity, Exploitation and Conservation), publishing September 22nd in the open-access journal
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The international team of researchers analyzed the results of 173 peer-reviewed studies investigating antipredator traits (behavioral and physiological) in 102 species of domesticated, captive, and urbanized mammals, birds, reptiles, fish and molluscs, while taking into account their position in the Tree of Life.The scientists found that contact with humans led to a rapid loss of animals antipredator traits, but simultaneously the variability between individuals initially increases and then gradually decreases over the generations in contact with human. The authors suppose that this two-step process is caused by reduced pressure from natural selection as a result of living in a safer environment, followed by artificial selection by humans for docility in the case of domestication.Animals showed immediate changes in antipredator responses in the first generation after contact with humans, suggesting that the initial response is a result of behavioral flexibility, which may later be accompanied by genetic changes if contact continues over many generations. The researchers also found that domestication altered animal antipredator responses three times faster than urbanization, while captivity resulted in the slowest changes. The results also showed that herbivores changed behavior more rapidly than carnivores and that solitary species tended to change quicker that group-living animals.The study demonstrates that domestication and urbanization exert similar pressures on animals and can result in rapid behavioral changes. The loss of anti-predator behaviors can cause problems when those domesticated or urbanized species encounter predators or when captive animals are released back into the wild. Understanding how animals respond to contact with humans has important implications for conservation and urban planning, captive breed programs, and livestock management.Dr. Geffroy adds "While it is well known that the fact of being protected by humans decreases antipredator capacities in animals, we did not know how fast this occurs and to what extent this is comparable between contexts! We also integrated physiological traits in the study but they were much less numerous that behavioral traits. We believe they should be systematically investigated to draw a global pattern of what is happening at the individual level. We need more data to understand whether this occurs also with the mere presence of tourists."
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Animals
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September 22, 2020
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https://www.sciencedaily.com/releases/2020/09/200922135731.htm
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Scientists identify new species of crystal-encrusted truffle, thanks to bonobos
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Mushroom-munching bonobos in the Democratic Republic of the Congo have introduced scientists to a new species of truffle.
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Commonly used by Congolese communities to bait traps for small mammals, Hysterangium bonobo is also savored by bonobos, an endangered species of great ape. Scientists say the truffle hints at vast reserves of undescribed fungal diversity in the region."Truffles aren't just for gourmet chefs -- they're also for our closest relatives," said Matthew Smith, an associate professor in the University of Florida department of plant pathology and curator of the UF fungal herbarium. "There's so much to learn about this system, and we're just scratching the surface."Edible mushrooms widely prized for their aromas, truffles are often ecosystem linchpins, and Although previous studies have reported bonobos eating truffles, this is the first such species identified."Kokolopori people have celebrated their interdependence with bonobos for generations," said Albert Lotana Lokasola, a graduate student at the University of Kisangani in northern Congo and a study co-author. "Our traditional knowledge of the diets of animals such as bonobos, duikers and rodents that includes food items new to science should be valued, preserved and protected."Smith said bonobos likely locate "Even though some truffles are specialized food items, they all evolved in a similar way," said Smith, who is also an affiliate associate curator in the Florida Museum of Natural History. "They smelled really good, so animals dug them up and spread the spores around."Study co-author Alexander Georgiev, a primatologist at Bangor University in Wales, collected samples of the truffles after he observed a group of wild bonobos eating them in Congo's Kokolopori Bonobo Reserve. He hoped a collaborator could identify the species, not knowing it was undescribed."Why they eat these, I'm not sure," he said. "Perhaps they like the taste of them. I personally love mushrooms and have never considered what I get out of them nutritionally. They just taste amazing."Georgiev said although he had never seen bonobos feed on truffles before, the local team of field assistants helping track them "instantly knew what was going on.""It's important to realize that even though this paper presents a 'novel' interaction and the description of a 'new' species for the Western scientific community, in reality these are interconnected associations that have been known about for untold generations by the locals in the region," added Todd Elliott, a Ph.D. candidate at the University of New England in Australia and the study's lead author. "As foreign scientists, we must take the time to ask and learn from indigenous people and locals in areas where we work because they usually intimately know about the organisms that we think are new."
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Animals
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September 22, 2020
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https://www.sciencedaily.com/releases/2020/09/200922112240.htm
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Wild birds as offerings to the Egyptian gods
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Millions of ibis and birds of prey mummies, sacrificed to the Egyptian gods Horus, Ra or Thoth, have been discovered in the necropolises of the Nile Valley. Such a quantity of mummified birds raises the question of their origin: were they bred, like cats, or were they hunted? Scientists from the CNRS, the Université Claude Bernard Lyon 1 and the C2RMF (1) have carried out extensive geochemical analyses on mummies from the Musée des Confluences, Lyon. According to their results, published on 22nd September 2020 in the journal
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Mammals, reptiles, birds: the tens of millions of animal mummies deposited as offerings in the necropolises of the Nile Valley bear witness to an intense religious fervour, and to the practices of collecting and preparing animals that undoubtedly contributed significantly to the economy from the Old Kingdom (3rd millennium BC) to Roman Egypt (1st-3rd centuries AD). However, the origin of these animals and the methods of supply remain unknown. For some tamed species, such as the cat, breeding was probably the most efficient way of supplying large numbers of animals for mummification. But unlike cats, bird mummies cover all stages of development, from egg to adult, which may indicate more opportunistic sourcing practices.In order to determine the origin -- breeding or hunting -- of the mummified birds, tiny fragments of feathers, bones and embalming strips were taken from 20 ibis and birds of prey mummies from the collections of the Musée des Confluences, Lyon. If these birds, which migrate in the wild, had been bred, their diet would have been homogeneous, of local origin and reflected in the uniform isotopic composition (2) of the animal remains, regardless as to whether that diet had been produced specifically or derived from that of coexisting humans.The various tissues were therefore dated using the carbon-14 method; and the isotopic compositions of oxygen, carbon, nitrogen, sulfur and strontium were measured, interpreted in terms of food sources and compared with those of contemporaneous human mummies. However, far from being homogeneous, these isotopic compositions showed a high variability and "exotic" signatures compared to those of ancient Egyptian humans: the birds were wild, migrating seasonally out of the Nile Valley.These results, combined with that of a genetic study carried out by another team, suggest the mass hunting and capture of birds as documented on certain tomb frescoes (for example on the wall of Nakht's tomb in the Theban Necropolis). Indeed, the Egyptians probably exerted a significant ecological pressure on wild bird populations long before the decline in avifauna observed today.(1) This work, coordinated by the Laboratoire de géologie de Lyon : Terre, planètes et environnement (CNRS/ENS de Lyon/Université Claude Bernard Lyon 1), is the result of a collaboration with the Musée des Confluences (Lyon), the Laboratoire d'écologie des hydrosystèmes naturels et anthropisés (CNRS/ Université Claude Bernard Lyon 1/ENTPE) and the Centre de recherche et de restauration des musées de France. Other laboratories also contributed to this research: Laboratoire de biologie et de biométrie évolutive (CNRS/Université Claude Bernard Lyon 1/VetAgroSup), Histoire et sources des mondes antiques (CNRS/Université Lumière Lyon 2/Université Lyon 3 Jean Moulin/Université Jean Monnet/ENS de Lyon) and Préhistoire et technologie (CNRS/Université Paris Nanterre).(2) A chemical element can exist in different versions, called isotopes, which are distinguished by their mass. Isotopic composition refers to the relative abundance of different isotopes of the same element, such as oxygen or carbon.
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Animals
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September 22, 2020
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https://www.sciencedaily.com/releases/2020/09/200922112230.htm
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New theory predicts movement of different animals using sensing to search
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All animals great and small live every day in an uncertain world. Whether you are a human being or an insect, you rely on your senses to help you navigate and survive in your world. But what drives this essential sensing?
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Unsurprisingly, animals move their sensory organs, such as eyes, ears and noses, while they are searching. Picture a cat swiveling its ears to capture important sounds without needing to move its body. But the precise position and orientation these sense organs take over time during behavior is not intuitive, and current theories do not predict these positions and orientations well.Now a Northwestern University research team has developed a new theory that can predict the movement of an animal's sensory organs while searching for something vital to its life.The researchers applied the theory to four different species which involved three different senses (including vision and smell) and found the theory predicted the observed sensing behavior of each animal. The theory could be used to improve the performance of robots collecting information and possibly applied to the development of autonomous vehicles where response to uncertainty is a major challenge."Animals make their living through movement," said Malcolm A. MacIver, who led the research. "To find food and mates and to identify threats, they need to move. Our theory provides insight into how animals gamble on how much energy to expend to get the useful information they need."MacIver is a professor of biomedical and mechanical engineering in Northwestern's McCormick School of Engineering and a professor of neurobiology (courtesy appointment) in the Weinberg College of Arts and Sciences.The new theory, called energy-constrained proportional betting provides a unifying explanation for many enigmatic motions of sensory organs that have been previously measured. The algorithm that follows from the theory generates simulated sensory organ movements that show good agreement to actual sensory organ movements from fish, mammals and insects.The study was published today (Sept. 22) by the journal MacIver is the corresponding author. Chen Chen, a Ph.D. student in MacIver's lab, is the first author, and Todd D. Murphey, professor of mechanical engineering at McCormick, is a co-author.The algorithm shows that animals trade the energetically costly operation of movement to gamble that locations in space will be informative. The amount of energy (ultimately food they need to eat) they are willing to gamble, the researchers show, is proportional to the expected informativeness of those locations."While most theories predict how an animal will behave when it largely already knows where something is, ours is a prediction for when the animal knows very little -- a situation common in life and critical to survival," Murphey said.The study focuses on South American gymnotid electric fish, using data from experiments performed in MacIver's lab, but also analyzes previously published datasets on the blind eastern American mole, the American cockroach and the hummingbird hawkmoth. The three senses were electrosense (electric fish), vision (moth) and smell (mole and roach).The theory provides a unified solution to the problem of not spending too much time and energy moving around to sample information, while getting enough information to guide movement during tracking and related exploratory behaviors."When you look at a cat's ears, you'll often see them swiveling to sample different locations of space," MacIver said. "This is an example of how animals are constantly positioning their sensory organs to help them absorb information from the environment. It turns out there is a lot going on below the surface in the movement of sense organs like ears and eyes and noses."The algorithm is a modified version of one Murphey and MacIver developed five years ago in their bio-inspired robotics work. They took observations of animal search strategies and developed algorithms to have robots mimic those animal strategies. The resulting algorithms gave Murphey and MacIver concrete predictions for how animals might behave when searching for something, leading to the current work.
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Animals
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921151318.htm
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Toxic masculinity: Why male funnel web spiders are so dangerous
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A team of University of Queensland researchers has revealed why male funnel web spiders develop much deadlier venom than their female counterparts.
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Led by UQ's Associate Professor Bryan Fry, the team has spent 20 years investigating delta-hexatoxins, the venom peptides that make funnel web spider venom so dangerous."Australian funnel-web spiders are infamous for causing human fatalities with this particular range of toxins," Dr Fry said."Delta-hexatoxins exert fatal neurotoxic effects in humans by keeping nerves turned on, so that they keep firing over and over again."It has puzzled scientists why these toxins are so deadly to humans, when they and other primates, haven't featured as either prey or predator during the spider's evolution."And we couldn't understand why most human deaths were being caused by male funnel web spiders, which seemingly had much deadlier venom than females."Using molecular analysis of the venom, Dr Fry and the team decided to take a closer look.Although 35 species of funnel-web spiders had previously been described, only eight delta-hexatoxins from five species had been analysed.Dr Fry and his team almost tripled the data -- profiling 22 novel delta-hexatoxins from the venom of 10 funnel-web species."Having much more data helped paint a much clearer picture, revealing an incredibly interesting evolutionary story -- one that had been hypothesised, but we've now proven," he said."These toxins had originally evolved to kill insects such as cockroaches and flies."But, when male funnel web spiders become sexually mature, they leave the safety of their burrow and wander quite considerable distances in search of females."This can be quite treacherous, and these male funnel web spiders started to encounter dangerous vertebrate predators, such as the dunnart, a small nocturnal mouse-like marsupial."The data shows that natural selection put the necessary pressure on to switch an insect-specific venom into a vertebrate-specific defensive venom."And, unluckily for us, we're a vertebrate species which copped it in the process."With a stronger evolutionary understanding of delta-hexatoxins, Dr Fry and his team are now endeavouring to put this new knowledge to use."We're hoping this research will give us a better understanding of exactly what funnel web spider venom does to the human body," he said."And -- medically speaking -- this could be critical for the design of evidence-based treatment strategies for bite victims."We're also hoping it will help researchers discover novel insecticides, finding better sources for insect-specific toxins."They're dangerous as hell, but male funnel web spiders offer us some real opportunities."
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Animals
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921130636.htm
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Tracking the working dogs of 9/11
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When veterinarian Cynthia Otto was in Manhattan in the wake of the 9/11 attacks helping support the search and rescue dogs, she heard rumors about the possible impact on the dogs' long-term health.
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"I was at Ground Zero and I would hear people make comments like, 'Did you hear that half of the dogs that responded to the bombing in Oklahoma City died of X, Y, or Z?' Or they'd say dogs responding to 9/11 had died," she recalls. "It was really disconcerting."It also underscored to her the importance of collecting rigorous data on the health of dogs deployed to disaster sites. An initiative that launched in the weeks after the Sept. 11, 2001, terrorist attacks did just that, and this week, 19 years later, Otto and colleagues' findings offer reassurance. Dogs that participated in search-and-rescue efforts following 9/11 lived a similar length of time, on average, compared to a control group of search-and-rescue dogs and outlived their breed-average life spans. There was also no discernable difference in the dogs' cause of death."Honestly this was not what we expected; it's surprising and wonderful," says Otto, director of the School of Veterinary Medicine's Working Dog Center, who shared the findings in the While postmortem results showed that dogs that deployed after the 9/11 attacks had more particulate material in their lungs upon their death, it seems this exposure didn't cause serious problems for the animals in life. The most common cause of death were age-related conditions, such as arthritis and cancer, similar to the control group.During and in the immediate aftermath of the 9/11 response, Otto and colleagues reached out to handlers to recruit search-and-rescue dogs into a longitudinal study that would track their health, longevity, and cause of death. They recruited 95 dogs that had worked at the World Trade Center, Fresh Kills Landfill, or Pentagon disaster sites. As a control group, they also included in the study 55 search-and-rescue dogs that had not deployed to 9/11.As part of being involved, the dogs received annual medical examinations, including chest X-rays and bloodwork. When the dogs died, the researchers paid for the handlers to have veterinarians collect samples of various organ tissues and send them for analysis at Michigan State University. Forty-four of the 9/11 dogs and 19 of the control group dogs underwent postmortems. For most of the other dogs in the study, the research team obtained information on cause of death from medical records or the handlers themselves.While the team had expected to see respiratory problems in the exposed dogs -- conditions that have been reported by human first responders to 9/11 -- they did not."We anticipated that the dogs would be the canary in the coal mine for the human first responders since dogs age faster than humans and didn't have any of the protective equipment during the response," Otto says. "But we didn't see a lot that was concerning."In fact, the median age at death for 9/11 dogs was about the same as the control group: 12.8 compared to 12.7 years. The most common cause of death for the dogs that deployed was degenerative causes -- typically euthanasia due to severe arthritis -- followed closely by cancer, though the risk of cancer was about the same as in control group dogs.Otto and her colleagues have ideas for why the foreign particulate matter found in some of the dog's lungs did not translate to ill health, though they emphasize that they're speculations, not yet based in data."For the pulmonary effects, it's somewhat easier to explain because dogs have a really good filtering system," Otto says. "Their lungs are different -- they don't get asthma, for example -- so it seems like there is something about their lungs that's more tolerant than in humans."She notes that working dogs tend to be extremely physically fit compared to pet dogs, perhaps counteracting any ill effects of the deployment conditions on health. But working dog handlers and trainers can always do more to focus on fitness and conditioning, especially because doing so could slow the progression of arthritis, a disease which played a role in the death of many dogs in the study."We know when people stop moving, they gain weight and that puts them at a higher risk of arthritis, and arthritis makes it painful to move, so it's a vicious cycle," she says. "The same can be true of dogs."The mind-body connection may also help explain the difference between humans and dogs and the longevity of the working dogs, Otto says, as dogs don't necessary worry and experience the same type of stress in the wake of a disaster."These dogs have an incredible relationship with their partners," Otto says. "They have a purpose and a job and the mental stimulation of training. My guess is that makes a difference, too."
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Animals
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921111640.htm
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Do rats like to be tickled?
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Not all rats like to be tickled but by listening to their vocalisations it is possible to understand in real-time their individual emotional response, according to new research by the University of Bristol. The study, published today [21 September] in
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Rats emit high frequency vocalisations which, when produced during human-simulated play or 'tickling', are thought to be similar to human laughter. Human laughter is complex and when a person is tickled, they may laugh even if they do not find the experience pleasurable. In rats, it has been impossible to know how much any individual rat 'likes' the experience because of limitations in method to directly measure their emotional response. In order to ask the question 'Do rats like to be tickled?' the researchers used a behavioural test developed at Bristol which provides a sensitive measure of an animal's individual emotional experience and they compared the data from this test with the animals vocalisations during 'tickling'.The researchers found not all rats like to be tickled and that some rats emitted very high numbers of calls whilst others did not, and these calls are directly related with their emotional experience. Rats which emitted the most calls had the highest positive emotional response to tickling but those who did not emit any or few calls did not show a positive response.Emma Robinson, Professor of Psychopharmacology in the School of Physiology, Pharmacology & Neuroscience, who led the research, said: "Being able to measure? a positive emotional response in animals is an important way to improve their welfare. What we have shown in this study is that the vocalisations made by rats in response to tickling are an accurate reflection of their emotional experience and something which is easy to measure."Should this be the case for other situations, measuring vocalisations could provide the simple, graded measure of emotional experience needed to better understand and improve the welfare of rats in a laboratory."This work is important for two reasons. Related to tickling-induced laughter in rats, the team's findings support previous work that shows that these vocalisations indicate a positive experience. However, rats seem to be more 'honest' with their response to tickling than humans or non-human primates and the amount they laugh directly relates to how positive they find the experience. The findings also suggest that the high frequency vocalisations which rats emit can provide researchers with a simple, graded measure of their individual affective experience.Being able to assess the welfare of animals accurately and objectively is important but is difficult to achieve. Without being able to ask an animal how it feels, researchers must rely on other methods which have their limitations. Researchers at Bristol have previously shown that the affective bias test used in this study can provide this type of objective measure, but it is highly specialist and time consuming to run so not readily applied in the wider laboratory animal setting. This research has found that human-simulated play or 'tickling' rats can cause a positive emotional state but not for all rats and by recording vocalisations it is possible to quickly identify which animals benefit from this type of enrichment.The research team is seeking further funding to expand this work to look in more detail at the relationships between vocalisation patterns and emotional state using the Bristol developed affective bias test developed to provide an objective baseline measure. The research team want to look at whether similar associations are found between vocalisations and positive and negative emotional experiences.The research was funded by a University of Bristol Research Postgraduate Studentship and a Medical Research Council project grant.
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Animals
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921111627.htm
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Cardiovascular health similarities between chimpanzees, humans
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Doctors like to remind patients not to monkey around with their health, suggesting that a good diet and regular exercise improve longevity.
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A new study on health in chimpanzees, which are the closest species to humans genetically, showed the benefits in what they eat and how they can travel and climb.When chimpanzees have a plant-based diet and substantial opportunities to exercise, they fall into "healthy" human ranges. Lab chimpanzees, whose diet and exercise were limited, showed conditions indicative of cardiovascular disease risk, more like sedentary people.Chimpanzees are critical for understanding the evolution of human health and longevity. Cardiovascular disease -- a major source of mortality during aging in humans -- is a key issue for comparative medicine.Prior data indicated that compared to humans, chimpanzees have high levels of blood lipids that can promote cardiovascular disease in humans. However, most work on chimpanzee heart health comes from the animals living in laboratories where lifestyles diverge from a wild context.Researchers from the University of Michigan and University of New Mexico partnered with wildlife veterinarians in Uganda and Congo to examine cardiovascular profiles in chimpanzees living in African sanctuaries. These chimpanzees occupy large rainforest enclosures, consume a diet of fruits and vegetables, and generally experience conditions more similar to a wild chimpanzee lifestyle.They measured blood lipids, body weight and body fat in 75 sanctuary chimpanzees during annual veterinary health check-ups, and then compared them to published data from laboratory-living chimpanzees.Free-ranging chimpanzees in sanctuaries exhibited lower body weight and lower levels of lipids, both risk factors for human cardiovascular disease. Some of these disparities increased with age, indicating that the free-ranging chimpanzees stayed healthy as they got older."Our findings support the hypothesis that lifestyle shapes health in chimpanzees, similar to effects in humans, and contribute to an emerging understanding of cardiovascular health in evolutionary context," said Alexandra Rosati, U-M assistant professor of psychology and anthropology.This is the first evidence that chimpanzees show differences in blood lipids related to their lifestyle, such as diet and ranging opportunities, and indicates that these health effects in humans are rooted in our evolutionary past, said Megan Cole, a researcher at the University of New Mexico and the study's lead author.Prior work suggested that chimpanzees have very high levels of blood lipids that are cardiovascular risk factors -- higher than humans in post-industrial societies in some cases. The work also showed that chimpanzees living a naturalistic life have much lower levels even as they age, providing a new reference for understanding human health. In biomedical research labs, chimpanzees have more limited space and often consume a processed diet (food such as primate chow), unlike wild chimpanzees."These results show how the high-quality, natural conditions that chimpanzees experience in African sanctuaries fosters their long-term health," Rosati said.The study's other authors include U-M's Averill Cantwell, Joshua Rukundo and Lilly Ajarova of the Chimpanzee Sanctuary and Wildlife Conservation Trust (Uganda), and Sofia Fernandez-Navarro and Rebeca Atencia of the Jane Goodall Institute Congo (Republic of Congo).
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Animals
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921083722.htm
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Male baboons with female friends live longer
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Close bonds with the opposite sex can have non-romantic benefits. And not just for people, but for our primate cousins, too.
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Drawing on 35 years of data, a new study of more than 540 baboons in Amboseli National Park in Kenya finds that male baboons that have close female friends have higher rates of survival than those who don't.Researchers have often assumed that when a male is friendlier to certain females, it's for the reproductive perks: to better protect his offspring, or to boost his chances of mating with her. But the new study points to an additional potential benefit: female friends may help him live a longer life.The team's findings will appear Sept. 21 in a special issue of the journal It's well known that people who have close friendships are more likely to live a long life than those who don't. In fact, human studies show that making and keeping friends can be as important for longevity as losing weight and getting exercise.In the last decade, similar patterns have been found in animals ranging from monkeys and horses to dolphins and killer whales. However most of this research has focused on females, whereas males are more of a mystery. The reason is that, in most social mammals, females typically spend their entire lives in the same group, while males come and go, leaving researchers with only a partial snapshot of their lives."It means there are lots of gaps in our understanding of male social life," said senior author Susan Alberts, chair of the evolutionary anthropology department at Duke University.Using statistical techniques to infer mortality risk at each age from sparse data, Alberts and colleagues looked at whether the link between survival and friendship was the same for male and female baboons.Since 1971, researchers have followed individual baboons in southern Kenya on a near-daily basis, noting who they socialized with and how they fared over their lifetimes as part of the Amboseli Baboon Research Project.Baboon besties don't catch up for coffee or bare their souls over beers. But they do spend time together grooming -- a give-and-take that involves sitting close together and stroking and picking through each other's fur, looking for ticks and other parasites. "It's a baboon's way of bonding and relieving stress, as well as providing some help with hygiene," Alberts said.Males spend very little time grooming each other, but they do groom with females, and not just when the females are fertile.Analyzing data for 277 males and 265 females, the team estimated the 'strength' of the bonds in each baboon's inner circle by measuring how often they spent time grooming with their closest friends.The researchers showed for the first time in a wild primate that, not surprisingly, both sexes benefit from having strong social ties. Just like humans, "baboon males live longer lives if they're socially connected," Alberts said.Males that maintained strong female friendships were 28% more likely to make it to their next birthday than their socially isolated counterparts.Indeed, the team found that the flip side of the friendship coin, social isolation, can be a bigger threat to male survival than the stress and dangers of fighting their way up the pecking order.Alberts says more work needs to be done to confirm that the link in baboons is in fact a causal one, and if so, to figure out exactly how the bonds of friendship affect physiology to lengthen their lifespans.But the researchers say their work on baboon social behavior suggests that the power of friendship may have deep evolutionary roots in the primate family tree."How do primate friendships get 'under the skin' to lengthen life?" Alberts said. "We still don't know; it's one of the most wonderful black boxes in my life."
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September 21, 2020
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https://www.sciencedaily.com/releases/2020/09/200921083720.htm
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Your cells look young for their age, compared to a chimp's
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Many humans live to see their 70s and 80s, some even reach 100 years old. But life is much shorter for our closest animal relatives. Chimpanzees, for example, rarely make it past age 50, despite sharing almost 99% of our genetic code.
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While advances in medicine and nutrition in the last 200 years have added years to human lifespans, a new study suggests there could be a more ancient explanation why humans are the long-lived primate.Part of the secret to human longevity, researchers say, may lie in chemical changes along the DNA within our cells that slowed the rate of human aging in the 7 to 8 million years since our ancestors went their separate ways from chimps.The findings will appear Sept. 21 in the journal In the last decade, researchers have found that chemical marks on the human genome -- modifications that can affect gene activity without altering the underlying DNA sequence -- actually change as we age.Studies have shown that certain sites along our DNA gain or lose chemical tags called methyl groups in a way that marks time, like a metronome. The changes are so consistent that they can be used as an "aging clock" to tell a person's age to within less than four years.The new study, led by researchers at Duke University and George Washington University, marks the first time such age-related changes have been analyzed in chimpanzees, said lead author Elaine Guevara, an assistant research professor of evolutionary anthropology at Duke.Guevara and colleagues analyzed some 850,000 of these sites in blood from 83 chimpanzees aged 1 to 59.Sure enough, they found that aging leaves its mark on the chimpanzee genome, just as it does in humans. More than 65,000 of the DNA sites the scientists scrutinized changed in a clock-like way across the lifespan, with some gaining methylation and others losing it."A lot of their genome shows an age-related pattern," Guevara said.The pattern was so reliable that the researchers were able to use DNA methylation levels to tell a chimpanzee's age to within 2.5 years, which is much more accurate than current methods for estimating a wild animal's age by the amount of wear on their molars.When the researchers compared the rates of change they found in chimps with published data for humans, the epigenetic aging clock ticked faster for chimpanzees.It's unknown whether these changes merely track the aging process or actively contribute to it, Guevara says.But the researchers hope such work could eventually offer clues to the gene regulatory mechanisms behind the physical and cognitive decline that often accompanies aging, and lead to new ways to fight aging-related diseases.
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Animals
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September 18, 2020
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https://www.sciencedaily.com/releases/2020/09/200918154519.htm
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Like humans, chimpanzees can suffer for life if orphaned before adulthood
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Researchers observed three chimpanzee communities of the Tai National Park. They kept full demographic records and collected fecal samples to conduct paternity tests on all new community members, for up to 30 years. Catherine Crockford, the lead author, says: "When we study our closest living relatives, like chimpanzees, we can learn about the ancient environmental factors that made us human. Our study shows that a mother's presence and support throughout the prolonged childhood years was also likely a trait in the last common ancestor that humans shared with chimpanzees six to eight million years ago. This trait is likely to have been fundamental in shaping both chimpanzee and human evolution."
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Major theories in human evolution argue that parents continuing to provide food to their offspring until they have grown up has enabled our species to have the largest brains of any species on the planet relative to our body size. Brains are expensive tissue and grow slowly leading to long childhoods. Ongoing parental care through long childhoods allow children time to learn the skills they need to survive in adulthood. Such long childhoods are rare across animals, equaled only by other great apes, like chimpanzees.Chimpanzees may have long childhoods, but mothers rarely directly provide them with food after ages four to five years when they are weaned. Mostly mothers let their offspring forage for themselves. So then what do chimpanzee mothers provide their sons that gives them a competitive edge over orphaned sons? We do not yet know the answer but scientists do have some ideas."One idea is that mothers know where to find the best food and how to use tools to extract hidden and very nutritious foods, like insects, honey and nuts," Crockford points out. "Offspring gradually learn these skills through their infant and juvenile years. We can speculate that one reason offspring continue to travel and feed close to their mothers every day until they are teenagers, is that watching their mothers helps them to learn." Acquiring skills which enable them to eat more nutritious foods may be why great apes can afford much bigger brains relative to their body size than other primates."Another idea is that mothers pass on social skills," Roman Wittig, last author on the study and director of the Ta? Chimpanzee Project, adds. "Again a bit like humans, chimpanzees live in a complex social world of alliances and competition. It might be that they learn through watching their mothers when to build alliances and when to fight."
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Animals
| 2,020 |
September 17, 2020
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https://www.sciencedaily.com/releases/2020/09/200917180401.htm
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Genetic adaptation to climate change is swift in crop pests
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Fruit flies have the uncanny ability to wake up from a months-long hibernation right when their food of choice -- say, the fruit from apple or Hawthorn trees -- is at its peak. They're active for a couple of weeks, eating and mating, before going dormant for the rest of the year. How this synchronization and remarkable timing happens has long been a mystery. In a world where global climate change is shifting the growing seasons, somehow the fruit flies keep up.
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In a new study, scientists have found many genes responsible for setting the flies' internal alarm clock and found that an imperceptibly slow development during dormancy is key to their rapid genetic adaption.The study is published in the journal Like bears or ground squirrels, fruit flies time their slumber to coincide with seasonal food availability. They even evolve quickly enough to, say, shorten their dormancy to exploit longer growing seasons. Though some species rely on the predictable shortening and lengthening of days to cue their hibernation (called photoperiodism), others appear to have an internal mechanism."In addition to the 24-hour circadian clock that we all have, many fruit flies have an internal seasonal timer," says study co-author Gregory Ragland, PhD, assistant professor of integrative biology at University of Colorado Denver. "They pop up, exploit their host, and disappear for nine or 10 months. There's a useful marriage between what we know about the ecology and genetics of this process, which is why we approached this as a collaborative effort."Unlike photoperiodism, much of this particular type of dormancy, or diapause, remains unknown. To investigate, a team of researchers led by Edwina Dowle, PhD, and Ragland at CU Denver, and Tom Powell, PhD, and Daniel Hahn, PhD, at University of Florida, joined forces with Jeff Feder, PhD, from University of Notre Dame and Stewart Berlocher, PhD, from University of Illinois at Urbana-Champaign.The group explored the hypothesis that differences in the rate of development during diapause drive the differences in the timing of seasonal activity. To test it, they collected two populations of the "Though it's actually a fly larva, this is the proverbial 'worm' in the apple that has evolved into a major crop pest by adjusting its timing to coincide with the early fruiting time of apple," says Ragland.The researchers monitored the apple and haw flies in a lab, simulating overwintering for designated time intervals. During each interval, they tested the flies' transcriptome, the bundle of RNA transcripts that determines traits. Sampling from the fly brains, researchers can compare snapshots of the RNA composition to measure developmental differences in the nervous system over long time periods."Watching their morphology over time, they appear to be in suspended animation" says Ragland. "But the brain transcriptome revealed subtle, yet steady developmental changes that accumulated over six months, eventually completing the process that cued them to pop out of dormancy."This provides a possible mechanism that flies use to set their seasonal timer. The process also appears to be key for the rapid evolution of seasonality -- apple flies have a slightly faster rate of development during dormancy, causing them to emerge earlier in the year.By comparing genetic variants differing in the two fly populations, researchers found that polygenic traits led to the quickness of adaptation; many genes, each with very small effects, worked together to determine the rate of development. The research illustrates that crop pests and insect disease vectors with similar biology may rapidly respond to changing climates by a similar genetic mechanism.Understanding the mechanics of diapause could also have a big impact on biomedical research, which depends on massive genetic stocks of the "People are interested in how to best preserve these flies because we can't cryogenically preserve them yet," says Ragland. "But if we could modify these lines to go into diapause, it would be a huge breathrough."
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Animals
| 2,020 |
September 17, 2020
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https://www.sciencedaily.com/releases/2020/09/200917135513.htm
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Sugar promotes sperm longevity in pig reproductive tract
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For many livestock species, artificial insemination (AI) is standard. But it can be tricky to achieve success the first time, thanks to variability in ovulation timing across the herd.
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Sperm remains viable for a day or two once they reach the oviduct, the tube connecting the uterus with the ovaries, in pigs and cattle. The amount of time sperm can be stored in the oviduct has a direct bearing on AI success; if ovulation happens just outside that window, the effort and expense of AI has to be repeated.A new University of Illinois study identifies a naturally occurring sugar that slows the maturation of sperm in pigs, opening up the possibility of extending sperm storage time within the female reproductive tract and increasing the chances of successful fertilization through AI."We knew there was something about the oviduct that was increasing sperm lifespan, but we didn't know what it was, exactly," says David Miller, professor in the Department of Animal Sciences at Illinois and co-author on the PLOS One study. "In this study, we discovered the molecules of the oviduct that bind sperm and increase their lifespan are complex sugars called glycans."After screening more than 400 sugars for their capacity to hold sperm, Miller's team had an inkling glycans were a candidate for pigs. To confirm, they isolated various sugars from the pig oviduct and applied them to beads in the laboratory, mimicking the oviduct lining. Compared with other sugars, the glycan-treated beads bound more sperm.But it wasn't just the physical act of slowing sperm down that increased their lifespan."We found out glycans were delaying the normal influx of calcium into sperm," Miller says. "Normally, calcium slowly comes into sperm as they mature, and that triggers them on their differentiation pathway, which makes them capable of fertilization. But binding to these immobilized sugars actually stops that calcium movement inside the cells. So it in a sense, the glycans are blocking their differentiation pathway and making them live longer."Miller sees several potential applications for this discovery. For example, it might be possible to conduct a fertility test for sperm using glycans in the lab. Sperm whose lifespan didn't increase when exposed to glycans would likely be less fertile and could be discarded. It might also be possible, someday, to introduce supplemental glycans in the oviduct during AI to create a larger reservoir of viable sperm.The results also extend scientists' understanding of fertility across animal species. Miller has done research to show a similar sugar binds and extends longevity in bovine sperm, and he's currently looking for genetic similarities in sperm storage organs among a wide variety of animal groups. Nature may use the same mechanisms to lengthen sperm lifespan after mating in several species.
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Animals
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