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January 10, 2018
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https://www.sciencedaily.com/releases/2018/01/180110112954.htm
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Seven new spider species from Brazil named after seven famous fictional spider characters
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Several literary classics from the fantasy genre are further immortalised and linked together thanks to a Brazilian research team who named seven new spiders after them.
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Spider characters from A Song of Ice and Fire, Harry Potter, The Lord of the Rings, The Silmarillion, H. P. Lovecraft's The Call of Cthulhu and the children's favourite Charlotte's Web and Little Miss Spider each gave a name to a new small cave-dwelling six-eyed spider inhabiting northern Brazil.Discovered in iron caves across the state of Pará, northern Brazil, the new species belong to the same Neotropical genus Interestingly, while all seven previously unknown species prefer staying in the shadows underground, none of them has the adaptations characteristic for exclusively cave-dwelling organisms, such as loss of pigmentation and reduced or missing eyes. They are classified as edaphic troglophile species, which means that they are capable of completing their life cycle away from sunlight, but are not bound to the deepest recesses. Often crawling near the surface, they can even be spotted outside the caves. To describe the species, the scientists collected about 2,000 adult specimens following a 5-year series of field collection trips.The list of 'fantasy' spiders begins with The name of Two species are named after spider characters from the classic works by J. R. R. Tolkien. On the other hand, the Brazilian spider's sibling -- Another staple in the 20th-century fantasy literature, the Harry Potter series, written by J. K. Rowling, also enjoys the attention of the researchers. The species The authors do not fail to pay tribute to much less violent spiders known from popular children books. David Kirk's Little Miss Spider inspires the name of The It is highly likely that there are many species and populations of this group of spiders yet to be discovered in the Neotropics, since the lack of previous studies in the region. However, the area and its biodiversity are impacted by mining.
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New Species
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January 9, 2018
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https://www.sciencedaily.com/releases/2018/01/180109124929.htm
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Mass extinctions remove species but not ecological variety
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Sixty-five million years ago, clouds of ash choked the skies over Earth. Dinosaurs, along with about half of all the species on Earth, staggered and died.
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But in the seas, a colorful population of marine bivalves -- the group including oysters, clams and scallops -- soldiered on, tucked into the crevices of ocean floors and shorelines. Though they also lost half their species, curiously, at least one species in each ecological niche survived.University of Chicago scientists documented this surprising trend in a study on extinctions published Jan. 5 in the Strangely, the scientists said, nothing of the kind is seen in a different kind of biodiversity loss: the loss of species today as you move from the warm tropics to the chillier poles. The number of species drops 80 percent to 95 percent from the tropics to the cold, snowy north and south, and functional variety also declines by 50 percent to 60 percent. Thus losing diversity due to changed environment is entirely possible -- all the more reason why it's strange to see such a pattern of survival in mass extinctions."Multicellular life almost didn't make it out of the Paleozoic era, but every functional group did. Then we see that functional diversity drops way down from tropics to poles; it parallels species loss in a way that's totally different from the big extinctions. That's wild -- really fascinating and unexpected and strange," said co-author David Jablonski, the William R. Kenan Jr. Distinguished Service Professor of Geophysical Sciences.This could have implications for how the mass extinction currently gathering steam could unfold and how badly it will affect Earth ecosystems, the authors said.Jablonski and graduate student Stewart Edie, who is the first author on the paper, ran the numbers for two major mass extinctions in history: the relatively gradual end-Paleozoic extinction, perhaps driven by changing climates and ocean composition, and later, the sharper end-Cretaceous extinction, thought to be caused by a meteor impact and/or volcanic eruptions. Though they are very different stresses, the same pattern emerged."The rug gets pulled out from underneath all the species," said Edie. "The landscape of the world completely and suddenly changed, making it all the more surprising that all functional types survived. Even the functional groups with only one or two species somehow make it through."The question is pressing because functional diversity is what makes ecosystems tick. Ecosystems are delicately balanced, and losing ecological roles throws a system out of whack: Think of a forest damaged when the deer population explodes because the wolves that prey on them are removed. That balance keeps soil fertile, oceans full of fish and grass growing for livestock."The big question is: Given that we're working on a mass extinction right now, which flavor will it be?" Jablonski said. "Will we have a tropic-to-poles type, where we lose half our functional groups and so ecosystems are massively altered? Or will it be a mass extinction where you can lose all these species, but the functional groups still somehow manage to limp on? We need to understand this."The other author on the paper was James W. Valentine with the University of California-Berkeley.
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New Species
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January 9, 2018
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https://www.sciencedaily.com/releases/2018/01/180109112410.htm
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Dead trees are alive with fungi
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Fungi that live on trees perform an important function in the forest ecosystem by breaking down dead wood. This is no easy feat, because wood is very resilient. It is held together by a biopolymer known as lignin, which together with cellulose and hemicellulose form the cell wall of woody plants and give the wood its stability. Fungi are able to break down the robust lignin and the flexible cellulose fibres by releasing enzymes that cause the polymers to degrade and become mineralised. As part of the ecosystem's cycle, the leftover material becomes part of the humus layer, which gives the soil its stability and forms the substrate for a new generation of trees.
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The study took the UFZ researchers to three areas of temperate forests in the Schorfheide-Chorin Biosphere Reserve, the Hainich National Park and the Schwa?bische Alb Biosphere Reserve, where they laid out around 300 dead tree trunks of eleven different species, each up to four metres long. The trees included seven deciduous species such as beech, oak, poplar and ash and four coniferous species: spruce, Scots pine, Douglas fir and larch. Three years later they returned to see what kind of fungal communities had established themselves in the trunks. The results were astonishing: "The diversity of fungi living in the trees was an order of magnitude greater than previously thought," says Dr Witoon Purahong, a soil ecologist based at UFZ in Halle and the first author of the study.The researchers identified between 22 and 42 operational taxonomic units (OTUs) per trunk. OTU is a scientific term used by molecular biologists to describe organisms that can be equated with individual species due to their DNA but do not already have a species name of their own. All in all, the UFZ team identified 1,254 OTUs in the dead trunks. In a previous study, researchers found just 97 fungal species living on the same logs -- about 12 times fewer than the UFZ scientists have now discovered. Dead conifers generally had greater species diversity of fungi than most deciduous trees. The greatest diversity occurred on Douglas fir, larch and oak and the smallest amount of diversity on beech and hornbeam.The reason why the UFZ soil ecologists found so many different species of fungi lies in the modern molecular technique they used. The researchers used a DNA sequencing technology known as next-generation sequencing to determine DNA markers of the fungi hidden in the wood. In previous, similar studies, only the fruiting bodies of the fungi growing on the surface of the dead trees were documented. This gave rise to the misleading impression that only a small number of fungus species inhabit dead trees. "It's like an iceberg: you can't see most of the fungi because they are inside the trunks in the form of a fine mycelium," says Prof François Buscot, who heads the department of soil ecology at the UFZ. In other words, the visible fruiting bodies are only a tiny part of the entire fungal communities inhabiting a dead tree.But it's not just the much greater diversity of fungi than previously suspected. The UFZ soil biologists also discovered that wood-inhabiting fungi prefer certain species of trees and don't simply have a general preference for either conifers or deciduous trees, as scientists previously assumed. They discovered seven such distinct fungal communities on deciduous trees and two on coniferous species. For example, oak and ash each harbour very specific communities fungal species whose composition is very different from those found on other deciduous trees. In the case of the conifers, the fungi growing in dead Scots pine were clearly distinct from those found in the other coniferous species investigated. It is not yet clear why there are such marked differences between the fungal communities in different species of dead wood. "Oak and ash have many identical characteristics, such as the wood structure and the carbon-to-nitrogen mass ratio, but they are very different when it comes to the number of fungal OTUs," says Witoon Purahong. The fungal communities found on these two species are more different from each other than compared tp any of the other tree species the team investigated, he adds.Now the soil ecologists from UFZ in Halle will focus on identifying the mechanisms that determine whether or not a fungus colonises a particular species of tree. "The millions of years of coevolution between trees and wood-inhabiting fungi could provide an explanation for their coexistence -- just as we see with symbiotic fungi, for example," says Purahong. What is fascinating, however, as Buscot adds, is that in some cases the specialisation of fungi on dead wood is greater than the oneof symbiotic fungi on living plants. The coexistence of communities of fungi, bacteria and invertebrates living in dead wood could also account for specific colonisation strategies.The results of this study have increased our understanding of the biodiversity of communities living in dead wood. This is important not only because it will enable us to improve the protection of wood-inhabiting fungi, which may be threatened by the expansion of forest monocultures. It is also important because the fungi that grow in dead trees include species already known as soil-dwellers, plant pathogens or symbiosis partners, which appear to use dead wood as a temporary habitat. "Dead wood is an integral part of forest ecosystems, which plays a vital role in the function and maintenance of biodiversity," says Buscot.
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New Species
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January 8, 2018
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https://www.sciencedaily.com/releases/2018/01/180108090235.htm
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A botanical mystery solved by phylogenetic testing
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Missouri Botanical Garden researchers used DNA testing to rediscover
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The goal of the authors was to understand where This study highlights the importance of living collections in botanical gardens, even those that are centuries old and might lack information about origin. The genetic analysis of these plants can play an important role in making new discoveries particularly about poorly known species. Dr. Christine Edwards, Dr. Burgund Bassuner, Dr. Porter Lowry, Senior Vice President Dr. James Miller, Senior Vice President Andrew Wyatt and Garden President Dr. Peter Wyse Jackson, Dr. Chris Birkinshaw, Christian Camara and Adolphe Lehavana served as authors."This project is a great example of how DNA analysis can be used to both bring new value to botanical garden collections and to make new discoveries. It is particularly exciting because it is rare to have the opportunity to rediscover a species that hasn't been seen in the wild for 200 years," said Edwards.
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New Species
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January 4, 2018
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https://www.sciencedaily.com/releases/2018/01/180104120320.htm
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Three new species of zoantharians described from coral reefs across the Indo-Pacific
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Three new species of zoantharians were discovered by researchers from the University of the Ryukyus and Kagoshima University, Japan, and the Palau International Coral Reef Center. Despite not being previously known, all three species were found widely across the Indo-Pacific, with at least two species found in the Red Sea, the Maldives, Palau, and southern Japan.
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Zoantharians, or colonial anemones, include species popular in the pet trade such as Zoanthus or Palythoa, but the new species are all much more cryptic, living in marine caves, cracks, or at depths below most recreational SCUBA diving (>20 m). The research was published December 29, 2017, in the open-access journal The three new species belong to the genus Antipathozoanthus, which contains species that only live on top of black coral colonies. However, surprisingly, one of the new species does not live on black corals, but instead in narrow cracks in coral reefs."We think that the new species, Antipathozoanthus obscurus, has evolved away from needing to be on top of black corals to take advantage of the available space in coral reef cracks," said lead researcher Hiroki Kise. "This is yet another example of how much diversity is right underneath our noses, but we still know nothing about it."Coral reefs, which are widely threatened by rising temperatures from global warming, are generally believed to harbour very high numbers of species, including yet many undescribed or unknown species.Amongst the other two new species is Antipathozoanthus remengesaui, named after the current president of Palau, Tommy Remengesau."Much of our work was based in Palau," said senior author Dr. James Reimer, "and we wished to acknowledge the fantastic support we have received from the nation. Palau is considered at the forefront of marine conservation, and much of this is thanks to President Remengesau's vision."While the new discoveries shed more light on our understanding of coral reef biodiversity, this work is far from done. In fact, the researchers themselves estimate they still have up to ten more zoantharian species to describe from the waters of Palau and Okinawa."Marine diversity of coral reefs is amazing, with new surprises all the time," said Kise, "and biodiversity scientists still have a lot more work to do."
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New Species
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December 26, 2017
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https://www.sciencedaily.com/releases/2017/12/171226105136.htm
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A classic Darwinian ecological hypothesis holds up -- with a twist
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New University of Colorado Boulder-led research shows that a long-held hypothesis about the factors that govern species ranges largely holds true, but may be the result of a previously underappreciated ecological mechanism.
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The prediction, first iterated by Charles Darwin in 1859, holds that climate factors will limit species expansion in more stressful environments (such as cold or dry regions), but that interactions with other species, like competition and pollination, will limit a species range in less stressful environments, where the climate is more temperate.The new CU Boulder study, published today in the journal "Darwin and others have said that what drives this pattern is gradients in density or diversity of interacting species, but instead it seems to be effects of stress on growth, survival, reproduction and germination of the plant species," said Allison Louthan, who led the research while completing her PhD dissertation in CU Boulder's Environmental Studies Program.At three field sites in central Kenya that varied in overall aridity, the researchers studied the population dynamics of Hibiscus meyeri, a common flowering plant, over a period of four years. The ubiquity of this particular flowering species, Louthan said, makes it a useful model system for studying differences in population dynamics across an ecological gradient.As expected, pollination, herbivory and competition with other herbs and shrubs played a strong role in setting the edges of the plant's range in the wetter sites. Those same interactions, however, did not seem to have a strong hand in H. meyeri's expansion to drier sites."This research provides a guide about where and when species interactions are important and where they are less important," said Louthan, now a post-doctoral researcher at Duke University. "Understanding the different forces that set limits to a species range and allow populations to expand or contract is crucial for understanding both ecological and evolutionary dynamics."Next, the researchers plan to expand their experimental method to other systems, in order to continue studying how a species reacts to various factors across a broad geographic area."Even before climate change, a major question was why species have the range limits that they do, and what the importance was of climate versus interactions with other species in setting these limits," said Dan Doak, a professor in CU Boulder's Environmental Studies Program and a coauthor on the study. "Now, with ongoing climate change, these questions are much more pressing. This work shows that multiple forces matter in shaping where a species lives and also that the mechanisms driving these effects are not what biologists have usually assumed."
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New Species
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December 26, 2017
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https://www.sciencedaily.com/releases/2017/12/171226104941.htm
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First-ever hybrid bird species from the Amazon
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A team of U of T Scarborough researchers have described the first known hybrid bird species to be found in the Amazon rainforest.
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Through a series of genetic and other tests the team have revealed that the golden-crowned manakin -- first discovered in Brazil in 1957 but not seen again until 2002 -- is in fact a hybrid species."While hybrid plant species are very common, hybrid species among vertebrates are exceedingly rare," says Associate Professor Jason Weir, senior author of the research.A hybrid species forms when two parental species mate to produce a hybrid population, which then stops being able to freely interbreed with the parental species. In this case the two parents are the snow-capped manakin, named for its bright snowy-white crown feathers, and the opal-crowned manakin, named for its brilliant iridescent crown feathers.Weir and his team, which included lead author and former graduate student Alfredo Barrera-Guzman, gathered genetic and feather samples over two separate field trips to Brazil. They were then able to sequence a large portion of the golden-crowned manakin's genome including 16,000 different genetic markers, finding that about 20 per cent of its genome came from the snowy-crowned, and about 80 per cent came from the opal-crowned.The researchers also used something called coalescent modelling to figure out at what point the golden-crowned split off from its parental species. They determined it was around 180,000 years ago when the two parental species originally mated, and that both parental species diverged from a common ancestor about 300,000 years ago, making all three very recent birds by Amazon rainforest standards."Most Amazon bird species diverged from their most recent relative around 1.5 to 4 million years ago, so these are all young birds by comparison" says Weir, an expert on the biodiversity of New World birds.The male golden-crowned has unique yellow crown feathers that are much duller than its parental species. To learn more about this unusual characteristic, the researchers took a closer look at the keratin structure of the crown feathers of all three bird species using an electron microscope. The two parent species each have very different structural arrangements of the keratin, which is responsible for creating the highly reflective colours that help males show-off to females in the dark rainforest interior. In the case of the golden-crowned, they discovered it had a mix of keratin structures from both parental species."The golden-crowned manakin ended up with an intermediate keratin structure that does a poor job of making either the brilliant white or the reflective iridescence of the parental species," says Weir.The golden-crowned manakin likely had duller white or grey feathers early on in its existence as a result of its keratin structure, but eventually evolved yellow feathers as an alternative way to attract females. The end result is a uniquely coloured species.The golden-crowned manakin lives in an area of the south-central Amazon Rainforest that is approximately 200 sq. km and is largely separated from areas where snow-capped and opal-crowned live by wide rivers that the birds are reluctant to cross. As Weir points out, it likely owes its survival as a species on being geographically isolated from its parental species at some point during a past ice age when rainforest coverage contracted, and wide rivers formed natural barriers."Without geographic isolation, it's very likely this would never have happened because you don't see the hybrids evolving as separate species in other areas where both parental species meet."There are some potential candidates of hybrid species in nature, like the red wolf of eastern North America, possibly a hybrid between the coyote and grey wolf. And while hybrids of two species do occur in nature, as Weir notes in most cases they won't develop unique characteristics to become its own separate species."This is what makes the golden-crowned manakin such a novel animal," he says.The research, which will be published in the
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New Species
| 2,017 |
December 23, 2017
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https://www.sciencedaily.com/releases/2017/12/171223134842.htm
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New species of marine spider emerges at low tide to remind scientists of Bob Marley
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It was 02:00h on 11 January 2009 when the sea along the coastline of Australia's "Sunshine State" of Queensland receded to such an extent that it exposed a population of water-adapted spiders. The observant researchers who would later describe these spiders as a species new to science, were quick to associate their emergence with reggae legend Bob Marley and his song "High Tide or Low Tide."
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In their paper, published in the open access journal Unlike the spiders which people are familiar with, the intertidal species, whose representative is Bob Marley's namesake, are truly marine. They have adapted to the underwater life by hiding in barnacle shells, corals or kelp holdfast during high tide. To breathe, they build air chambers from silk. Once the sea water recedes, though, they are out and about hunting small invertebrates that roam the surfaces of the nearby rocks, corals and plants.The new species, listed under the scientific name of Both sexes are characterised by predominantly red-brown colours, while their legs are orange-brown and covered with a dense layer of long, thin and dark grey hair-like structures. The females appear to be larger in size with the studied specimen measuring nearly 9 mm, whereas the male was about 6 mm long.While the exact distribution range of the newly described species remains unknown, it is currently recorded from the intertidal zones of the Great Barrier Reef on the north-eastern coast of Queensland."The song 'High Tide or Low Tide' promotes love and friendship through all struggles of life," explain the authors for their curious choice of a name. "It is his music that aided a field trip to Port Douglas in coastal Queensland, Australia, to collect spiders with a highly unique biology."Apart from reporting their research, the scientists use their paper to pay tribute to a German naturalist from the late 19th century -- Amalie Dietrich, as well as the famous Jamaican singer and songwriter. Both admirable figures, even if representative of very different fields, are seen by the authors as examples of "the adventurous and resilient at heart" human nature in pursuit of freedom and independence.
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New Species
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December 23, 2017
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https://www.sciencedaily.com/releases/2017/12/171223134740.htm
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Scientists identify hidden genetic variation that helps drive evolution
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Identifying complex mutations in the structure of an organism's genome has been difficult. But in a new study published online in
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Their approach identifies extensive genetic variation in the fruit fly genome that have previously escaped discovery. Their results will help push researchers closer to understanding how complex mutations in genomes drive disease and evolution."For the first time in animals, we have assembled a high-quality genome, permitting the discovery of all the genetic differences between two individuals within a species," said Mahul Chakraborty, a postdoctoral scholar in the Emerson laboratory and first author on the study. "We uncovered a vast amount of hidden genetic variation during our analyses, much of which affects important traits within the common fruit fly, D. melanogaster."Unlike standard approaches that rely on the same sequencing technology that delivered the so-called $1,000 genome, the team's approach relies on reconstructing the whole genome from a newer technology that is capable of reading much larger pieces of the genome. The use of such long molecule sequencing equipped Chakraborty and Emerson to unravel complex changes that alter the structure of the genome."This study is the first of its kind in complex organisms like the fruit fly. With this unique resource in hand, we have already characterized several candidate structural variation which show evidence for phenotypic adaptation, which can function to drive species evolution," said Emerson.In exploring how some of these newly identified structural genome changes might contribute to fruit fly evolution, the group were drawn to an enzyme family that has been associated with resistance to pesticides and cold preference, among many other functions. They found that structural changes crank up the output of one of the genes by 50-fold, suggesting how such flies attain increased nicotine resistance.According to the researchers, the fact that so much variation escaped notice in D. melanogaster -- a species with relatively simple genomes less like to hide variation -- suggests that our own genomes, and those of the species we eat, are harboring an even larger store of medically and agriculturally important genetic variation.
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New Species
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December 22, 2017
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https://www.sciencedaily.com/releases/2017/12/171222090329.htm
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West African dolphin now listed as one of Africa's rarest mammals
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A group of scientists now considers a little-known dolphin that only lives along the Atlantic coasts of Western Africa to be among the continent's most endangered mammals, a list that includes widely recognized species such as gorillas, African wild dogs, and black rhinos, according to WCS (Wildlife Conservation Society) and the IUCN's (International Union for Conservation of Nature) Cetacean Specialist Group.
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The latest assessment of the Atlantic humpback dolphin (Growing up to 2.5 meters (more than 8 feet) in length, the Atlantic humpback dolphin is gray in color and has a characteristic hump just below its dorsal fin. These dolphins are shy, occur in small groups, and rarely venture more than a few kilometers from shore. They are highly susceptible to human activities in coastal waters, and threats include entanglement in fishing gear, offshore construction such as port development, and hunting for human consumption."Our recent assessment suggests that the global population of the Atlantic humpback dolphin likely numbers fewer than 1,500 breeding adults distributed among several isolated sub-populations, most of which appear to be very small," said Tim Collins, of WCS's Ocean Giants Program and the Africa Coordinator of the IUCN's Cetacean Specialist Group.The presumed range of the Atlantic humpback dolphin stretches more than 7,000 kilometers along the coastal areas of Western Sahara to central Angola. The previous "Vulnerable" listing for the species was based largely on the assumptions that dolphins were more abundant in areas where the species was known to occur and the presumption of occurrence in many areas had not been surveyed.For the new Red List assessment, researchers conducted a thorough review of the available data, which strongly suggest that the dolphins occur in very low and apparently declining numbers throughout most or all of their range. Most populations are extremely small and several appear to be isolated. Declines have been observed (or are suspected) for every known population, and their continued decline is considered inevitable given the ongoing expansion of identified threats throughout the species' known range.Bycatch in fisheries, the principal cause of the declines, has been identified or suspected everywhere the species has been studied. Hunting is known from several areas, and the threat of coastal development in remaining habitats is increasingly prevalent. Appropriate management interventions that limit habitat loss, bycatch and hunting are limited or entirely lacking across most of the range. In the absence of targeted and sustained conservation management efforts, the researchers conclude that the species will continue to decline.Researchers add that several marine protected areas provide Atlantic humpback dolphins and other marine wildlife with important refuges that can provide marine managers with a foundation for complementary conservation efforts. This includes the recent creation of a marine protected area network in Gabon.Howard Rosenbaum, Director of WCS's Ocean Giants Program and a member of the IUCN Species Survival Commission's Cetacean Specialist Group, said: "The new Critically Endangered listing will hopefully provide greater attention and resources to mitigate primary and cumulative threats faced by the Atlantic humpback dolphin, as well as proactive strategies for protecting the species and its vital habitats in key parts of the range."Randall Reeves, Chairman of the IUCN Species Survival Commission's Cetacean Specialist Group, said: "Particularly in view of the impending extinction of the vaquita (a small porpoise endemic to Mexico's Gulf of California) due entirely to overkill in fishing nets, we need to do a better job of not just assessing the present condition of riverine and coastal small cetaceans, but also of looking ahead and anticipating what is likely to happen to species like the Atlantic humpback dolphin unless current trends are reversed, and soon."In addition to long-term field studies on Atlantic humpback dolphins, WCS scientists have also produced important findings on humpback dolphins living in the in the Atlantic, Indian and Pacific Ocean basins, specifically to resolve confusing taxonomic questions about which populations should be considered full-fledged species or related subspecies. These investigations determined that four species exist: the Atlantic humpback dolphin; the Indian Ocean humpback dolphin (Sousa plumbea); the Indo-Pacific humpback dolphin (Sousa chinensis); and a newly described species -- the Australian humpback dolphin (All four species live in coastal habitats and face the same threats; entanglement in fishing nets, coastal development, ship strikes, and increasingly hunting. The Indian Ocean humpback dolphin is listed as "Endangered," whereas the Indo-Pacific and Australian humpback dolphins are both listed as "Vulnerable."
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New Species
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December 21, 2017
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https://www.sciencedaily.com/releases/2017/12/171221143151.htm
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An integrated assessment of vascular plants species of the Americas
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Missouri Botanical Garden researcher Dr. Carmen Ulloa is the lead author of "An Integrated Assessment of Vascular Plant Species of the Americas," published today in
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Establishing a checklist like this one has long been a goal of the Garden. In 2015, Ulloa started to research what already existed among existing Garden projects and other botanical institutions across the Americas. She then contacted the editors of the 12 major projects in the last 25 years that served as the basis for this larger checklist including the checklists of Bolivia, Brazil, Colombia, Ecuador, the Guianas, Mexico, Peru, the Southern Cone (Argentina, Chile, Paraguay, Uruguay), Venezuela, and the West Indies. Two partially published datasets of the Flora of North America North of Mexico and the Flora Mesoamericana were also used.The Garden's plant database, Tropicos® was used as the projects data repository for the project. In the process, more than 25,000 names were added to Tropicos before a final list was compiled."This is the first time we have a complete overview of the plants of the Americas," said Ulloa. "It represents not only hundreds of years of plant collecting, and botanical research, but 6,164 botanists who described species that appear on this list. It is vital we have this information so that we know what each species is for conservation purposes."Co-author Dr. Robert Magill first developed Tropicos in the early 1980s on tiny Osborne 01 microcomputer. Today, it is the world's largest botanical database. It is accessed more 70 million times each year by researchers around the world. It is a link to the past, a digital version of 4.4 million specimens in the Garden's expansive Herbarium. It is also a link to the future, the basis of a larger project, the World Flora Online. The Missouri Botanical Garden and more than 40 other institutions are working to develop the World Flora Online with the goal of documenting all known plant life by 2020.A number of co-authors are current or former members of the Missouri Botanical Garden research staff including Dr. Gerrit Davidse, Heather Stimmel, Dr. James Zarucchi, Dr. Peter Jørgensen, Magill and Garden President Emeritus Dr. Peter Raven. In addition to this, Dr. Tom Croat and Dr. Charlotte Taylor are both acknowledged in the study's supplemental material for having more than 400 described plant species on the Americas list.Each year, Missouri Botanical Garden researchers name hundreds of new species of plants with unknown potential. Though the process starts at collection at sites around the world, the real work takes places through the examination and comparison of all known species in Herbaria and in Tropicos. Digital records make it possible for those researchers working around the world to access information on their way to a new discovery. Other recommendations in the paper, including the support and development of taxonomic expertise, more focused research and embrace of new technologies are shared goals of the Garden for its work in around the world.
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New Species
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December 22, 2017
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https://www.sciencedaily.com/releases/2017/12/171222090340.htm
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Ancient dolphin species Urkudelphis chawpipacha discovered in Ecuador
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A new dolphin species likely from the Oligocene was discovered and described in Ecuador, according to a study published December 20, 2017 in the open-access journal
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Many marine fossils described in previous research have been from long-recognized temperate regions such as South Carolina, off the coast of Oregon, Hokkaido and New Zealand. Few equatorial and polar fossils are currently known.While in the tropical region of Santa Elena Province, Ecuador, the authors of this study found a small dolphin skull, which they identified as representing a new species, The fossil is one of the few fossil dolphins from the equator, and is a reminder that Oligocene cetaceans may have ranged widely in tropical waters.This study was supported by an UPSE project IN-P5-2016-1 for equipment at UPSE, and YT thanks support of a trip to Ecuador. This work has also been supported by the Agencia Estatal de Investigación (AEI) from Spain and the European Regional Development Fund of the European Union (CGL2016-76431-P) and the project CGL2015-68333 (MINECO/FEDER, UE).
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New Species
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December 18, 2017
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https://www.sciencedaily.com/releases/2017/12/171218131332.htm
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85 new species described by the California Academy of Sciences in 2017
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In 2017, researchers at the California Academy of Sciences added 85 new plant and animal species to the family tree, enriching our understanding of Earth's complex web of life and strengthening our ability to make informed conservation decisions. The new species include 16 flowering plants, one elephant-shrew, 10 sharks, 22 fish, three scorpions, seven ants, 13 nudibranchs, seven spiders, three wasps, one fossil sand dollar, one deepwater coral, and one lizard. More than a dozen Academy scientists -- along with several dozen international collaborators -- described the discoveries.
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Proving that our planet contains unexplored places with never-before-recorded plants and animals, the scientists made their finds over five continents and three oceans, venturing into vast deserts, diving to extreme depths, and scouring rugged mountain ranges. Their results help advance the Academy's mission to explore, explain, and sustain life on Earth."Despite tireless efforts to explore from the far-flung corners of the globe to our backyard crannies," says Dr. Shannon Bennett, Academy Chief of Science, "scientists estimate that more than 90 percent of species have yet to be discovered -- with many going extinct before we even know they exist. We are not only losing members of the tree of life; we are also forfeiting potential breakthroughs in medicine, agricultural pollinators, water purifiers, and many other critical components of a healthy planet. Our understanding of sustainable ecosystems -- and the diversity of species comprising them -- will help us chart a successful way forward for the future of all life on Earth."Below are a few highlights from the 85 new species described by the Academy in 2017.Every spring, plants in the princess flower family color the rocky plateaus in Southeastern Brazil with flowers ranging from shades of purple, magenta, and pink to white, yellow, and orange. "The plants have evolved small, thick leaves to retain water during the dry season and a woody underground root for water storage and weathering periodic fires," says emeritus curator of botany Dr. Frank Almeda. A newly described species of brown-and-white, charismatic butterflyfish made a fantastic, 7,000-mile journey before surprising scientists with its unknown status. Live specimens collected from 360 feet beneath the ocean's surface in the Philippine's Verde Island Passage escaped special notice until a single black fin spine tipped off aquarium biologists back in San Francisco."We named this reef fish Academy curator of invertebrate zoology Dr. Terry Gosliner has discovered one thousand species of sea slugs (and counting) -- over half of all species known to science -- and this year he formally describes 13 of his finds. Eight of the new species were described from the Philippines and are members of the bat-wing family. Unlike most sea slugs, they are capable of swimming. "They have tiny 'wings' on the side that they flap to move through the water," says Gosliner. He named one species A painstaking revision of a large group of Neotropical "club-tailed" scorpions led to three new descriptions of colorful species (and two new groups) hailing from the tropical regions of North, Central, and South America. "One wild thing about this group is that many species have the unique ability to make sounds by rubbing a specialized comb-like structure against their sandpaper-like abdomen," says arachnology curator Dr. Lauren Esposito. She says the warning is audible to the human ear, "sounding like a hiss, or a maraca shaking," and is likely a loud way to tell predators: back off.For one month out of the year, a rare flowering tree in the Oaxaca region of Mexico opens creamy white blooms around mid-afternoon. Hummingbirds visit until the light fades, and at dusk, bats arrive to pollinate throughout the night. By dawn, the flowers have dropped and the tree -- recently named In a triumphant return, Academy scientists elevated a subspecies of elephant-shrew known as This year seven new species of ants join the tree of life in their march toward global domination. (Ants rival humans having colonized almost every landmass on Earth.) One new species, collected in Taiwan, was described from the Stigmatomma genus of 'Dracula ants' infamous for drinking the blood of their larvae. "Members of this cryptic group are rarely collected," says postdoctoral researcher Dr. Flavia Esteves. "It's an exciting new species to describe since it spends the entirety of its life beneath the soil or inside rotten logs." Entomology curator Dr. Brian Fisher has uncovered numerous Dracula ants in Madagascar, where he opened the nation's first biodiversity center and has spent two decades researching insect diversity. This year he discovered an additional six species from the island, increasing his impressive career tally to over 1,000 new ant finds.From "Austin's guitarfish" to the "Long-nosed African spurdog," many recently described species of sharks sound like cartoon characters from a faraway world. Indeed, several new finds from the ghost shark group are "rarely encountered because they inhabit great depths of over 7,000 feet," says ichthyology research associate Dr. David Ebert, who tallied ten new species of sharks and rays this year. "However, as commercial fisheries move into deeper waters these species are being discovered and described at a higher rate than ever."In a 2011 deepwater exploration of the Philippines' Verde Island Passage -- the "center of the center" of marine biodiversity -- a beam trawl drew an octocoral from over 1,000 feet beneath the surface. (Octocorals are distinguished from other corals by the eight tentacles on their polyps.) But it would take close inspection to confirm the denizen of the deep as a new-to-science find. "By using an electron microscope, I was able to pinpoint a distinguishing feature -- tiny mineralized structures known as spicules that are common to all octocorals were markedly rectangular in shape," says octocoral expert and invertebrate zoology curator Dr. Gary Williams, who formally described the species as Research associate Dr. Charles Griswold and his team described seven new spiders this year, and two are named in honor of peace.
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New Species
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December 18, 2017
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https://www.sciencedaily.com/releases/2017/12/171218090958.htm
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Mysterious new seafloor species sheds light on early animal evolution
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Japanese researchers have discovered a new species of the enigmatic marine worm
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The researchers, centered at the University of Tsukuba, described two specimens of MicroCT scanning, a method not previously applied to "We also extracted DNA and sequenced the mitochondrial genome and partial Histone H3 gene sequences," co-author Hideyuki Miyazawa explains."Molecular phylogenetic analysis confirmed that "Species within this genus have previously been divided into 'shallow' and 'deep' subgroups, and our results place Research on Xenoturbella has been limited by the inaccessibility of specimens in their seafloor habitats hundreds or thousands of meters below the surface. This new discovery may offer a solution. As co-author Hisanori Kohtsuka explains, "because one habitat where X. japonica was found is easily accessible from a marine station, this new species promises to be valuable for future research on bilaterian and deuterostome evolution."
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New Species
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December 15, 2017
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https://www.sciencedaily.com/releases/2017/12/171215135122.htm
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Complex, old-growth forests may protect some bird species in a warming climate
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Old forests that contain large trees and a diversity of tree sizes and species may offer refuge to some types of birds facing threats in a warming climate, scientists have found.
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In a paper published in Researchers studied 13 bird species that have been tracked annually in the U.S. Geological Survey's annual Breeding Bird Survey, one of the most comprehensive efforts of its kind in North America. Only two -- the Wilson's warbler and hermit warbler -- showed negative effects from rising temperatures over the past 30 years, but actual counts of both species show that their populations are stable or increasing in areas that contain high proportions of old-growth forest.A team led by Matthew Betts, professor in the College of Forestry, reached their conclusions by analyzing data for bird populations, forest structure and climate across northwestern North America. The researchers used satellite imagery to determine the amount of old-growth forest within about 450 yards of each 25-mile-long bird survey route.The findings provide an additional reason for old-growth forest conservation, said Betts. "Managers hoping to combat the effects of climate change on species' populations may now have an additional tool -- maintaining and restoring old-growth forest." He noted that this is important because management recommendations from biodiversity and climate studies have traditionally been sparse. Such studies have tended to focus on moving species to cooler climates or simply reducing carbon emissions.Wilson's warbler winters in Mexico and breeds during the late spring and early summer along the West Coast and across northern North America from Alaska to New England and the Canadian Maritimes. Although it occurs in early-stage as well as mature forests, it is declining at a rate of about 2 percent per year in the Pacific Northwest.The hermit warbler also winters in Mexico but breeds exclusively along the West Coast as far north as Washington. Its populations are relatively stable but declining in landscapes with low amounts of old-growth forest.Additional research will be needed to identify the specific features of mature forests that buffer the effects of warming temperatures on birds. One possibility, the researchers said, is that the large trees themselves function as "heat sinks" during warm periods and thus moderate temperatures. Multiple canopy layers may also provide climate buffering effects.
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New Species
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December 14, 2017
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https://www.sciencedaily.com/releases/2017/12/171214101522.htm
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Researchers shine a spotlight on illegal wild orchid trade
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Large-scale commercial trade of wild orchids is a pressing, but little-recognised conservation problem, according to researchers.
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Orchids are one of the largest families of flower plants in the world, and -- on paper -- they are among the most well protected.From edible orchid cake in Tanzania and ornamental orchids in Thailand and Brazil, to medicinal orchids in Nepal, these plants are highly sought after commodities.The majority of the global orchid trade consists of legal, greenhouse-grown flowers and plants.However, many orchid species are also harvested from the wild for local, regional and international trade, without the necessary harvest or trade permits, driving new concern for orchid conservation in many parts of the world.And a great deal more can be done to protect them from illegal and unsustainable trade, according to the first global overview of the illegal orchid trade, published in the Botanical Journal of the Linnean Society by a group of international researchers from the IUCN Species Survival Commission's Orchid Specialist Group -- Global Trade Programme[Office1] .Dr Jacob Phelps of Lancaster University said: "Orchids have been harvested from the wild for generations, but commercial trade in orchids is often being unreported, and so has garnered little attention. While many people think of orchids as only ornamental plants, orchids are also harvested, grown, and traded globally for use in a range of food products, as constituents within cosmetics, and traditional medicines. This review gives us the first glimpses into the massive scale and diversity of the illegal orchid trade globally, and of the conservation challenges ahead."Researchers took their review to the CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) meeting in Geneva (26 Nov. -- 01 Dec. 2017) with a plea for countries within the CITES Convention to do more to regulate trade of this critical plant group.Dr Amy Hinsley of the University of Oxford said : "All species of orchids are listed on the CITES Convention, which sets rules about the international trade of protected species. Orchids represent more than 70% of species covered by the Convention, so we should we be talking more about them."Researchers say the review provides evidence that efforts to reduce illegal wildlife trade are suffering from a distinct case of "plant blindness," and that a great deal more can be done to stop illegal and unsustainable plant trade, and to promote sustainable forms of trade.
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New Species
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December 12, 2017
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https://www.sciencedaily.com/releases/2017/12/171212141506.htm
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How honey bee gut bacteria help to digest their pollen-rich diet
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The honey bee gut is colonized by specialized bacteria that help digest components of the floral pollen diet and produce molecules that likely promote bee health. In a study publishing 12 December in the open access journal
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The authors measured the repertoire of simple chemical compounds -- the so-called "metabolome" -- from bee guts. They then compared the gut metabolomes of bees colonized with each bacterial species individually and in combination. By this method, the team identified what each bacterial species contributes to the bee digestion and the various strategies bacteria deploy to co-exist in the animal gut.Of particular note, they identified one several species of the genus Lactobacillus that digests convert specific plant compounds called flavonoids -- abundant in pollen and recently linked to the health of mice and humans through their breakdown by the gut microbiota. Another bee gut bacterial species, Honey bees, a principal pollinator in agriculture and natural environments, have suffered from colony declines in recent years. The gut bacteria in bees and their pollen-rich diet are known contributors to honey bees' health, and understanding the functions of the various bacteria could have implications for colony health as a whole."We took advantage of the key characteristics of the bee gut microbiota: its simplicity." says Philipp Engel, the corresponding author of the study. Contrary to human gut microbiota, the bee gut is composed of only a few bacterial species. This makes analyzing each member separately and determining its contribution to the overall metabolite changes in the gut feasible.""We have identified many exciting metabolic functions of bee gut bacteria. The next step is to understand how these functions impact colony's health so that one day we can apply our findings in apiaries."
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New Species
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December 12, 2017
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https://www.sciencedaily.com/releases/2017/12/171212091042.htm
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Native fish species at risk following water removal from the Colorado River
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Agriculture and domestic activities consume much of the Colorado River water that once flowed to the Colorado Delta and Northern Gulf of California. The nature and extent of impact of this fresh-water loss on the ecology and fisheries of the Colorado Delta and Gulf of California is controversial. A recent publication in the journal
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Unique ecological species evolved in the historically fresher Colorado Delta and adapted to this environment. These fish are distinct from closely related species in the historically saltier estuaries found in other regions of the Gulf. However, the Colorado Delta is now more similar in salinity to many of the other estuary systems in the Gulf of California, suggesting that the ecological factors that separated species may have broken down.Workers from UCLA examined species of silverside fish in a genus that only occurs in the Gulf of California. One species, Colpichthys hubbsi, lives exclusively in the Delta and is listed as endangered due to its restricted range. Morphologic and genetic anayses demonstrate that this species hybridizes along the western edge of the Delta with Colpichthys regis, a widespread relative distributed in estuaries throughout the Gulf. Although hybrids could be recognized morphologically, there was no evidence of hybridization in earlier museum collections.Furthermore, the genes from the widespread species were found to penetrate the range of the Delta specific species, but there were no genes from the Delta species found elsewhere in the Gulf. Thus, there was clear evidence of gene movement in one direction between the two species. This potentially places the Delta species at risk of extinction as its genome is swamped or replaced by the genes of the other species.In this particular case, more work is needed to clarify the detailed causes of species separation and the nature of ongoing impacts to the genome of the Delta species. However, there are broader issues at stake than a single species. Other groups of fishes and crabs also appear to have evolved as ecological species restricted to the Colorado Delta. These may also be at risk. More broadly, water extraction continues to accelerate in large river systems around the world. Thus, loss of ecological species in deltas and estuaries around the world is also likely accelerating.Museums and institutions in Mexico, including the Los Angeles County Museum of Natural History, Scripps Institution of Oceanography CIAD in Guaymas facilitated this work by sharing their collections and supporting field work.
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New Species
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December 11, 2017
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https://www.sciencedaily.com/releases/2017/12/171211122818.htm
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Cyanobacteria in lakes: Risks linked to loss of diversity
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The composition of cyanobacterial communities in peri-alpine lakes has become increasingly similar over the past century. Climate warming and a period of eutrophication have favoured in particular potentially toxic species which can adapt rapidly to environmental changes. These are the findings of an Eawag-led study analysing DNA extracted from sediment cores.
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Cyanobacteria -- also known as blue-green algae -- are adaptable organisms which lie at the bottom of the food chain in lakes. Around a century ago, each lake had its own characteristic cyanobacterial assemblage. Now, according to a study by Swiss and French researchers published in In the study, using cores retrieved from 10 peri-alpine lakes, the scientists investigated cyanobacterial DNA from dated sediment layers. Statistical analysis of the data revealed that community composition has become increasingly uniform across all lakes over the past century, even though the number of genetically differentiable "species" has increased in some lakes. Since the 1950s, the proportion of species groups found in few lakes has declined, while the proportion of common ones (found in many lakes) has increased fourfold.Two main factors driving this trend are identified in the study -- rising temperatures and the eutrophication experienced by many lakes in the 1960s and 1970s. Higher temperatures lead to longer periods of stable stratification, i.e. a reduction in lake mixing (as warmer, lighter surface water does not sink). In Lake Zurich, for example, this has favoured the dominance of the potentially toxic "Burgundy blood alga" Planktothrix rubescens, whose reddish blooms can pose problems for water suppliers. First author Marie-Eve Monchamp comments: "In general, the beneficiaries of these developments seem to be those species which can actively influence their vertical position in the lake and which need less light to survive -- and that includes many toxic species." Among these -- as well as the Burgundy blood alga -- are species of the genus Microcystis and the invasive species Dolichospermum lemmermannii. The latter was previously observed mainly in lakes north of the Alps, but is now also spreading in southern lakes.Interestingly, the homogenization trend is still ongoing despite the reduction in phosphorus concentrations which has occurred since the mid-1970s. The authors attribute this partly to the fact that variation in environmental conditions from one lake to another is also decreasing. There has been a decrease in temperature differences between lakes south and north of the Alps. And, lastly, concentrations of the other important nutrient, nitrogen, have remained at a relatively constant high level since the 1970s.
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New Species
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December 11, 2017
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https://www.sciencedaily.com/releases/2017/12/171211105834.htm
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Six new species of silky anteater
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In a recent study published in
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The new study combines genetic and anatomical data to review the classification of silky anteaters. Led by former Dr. Flávia Miranda, the team of researchers analyzed 33 samples of DNA and examined more than 280 specimens of this rare mammal in museums worldwide. The researchers discovered that what was formerly considered a single species Besides Additionally, three other species were described as new, including Thomas' silky anteater (Silky anteaters are small nocturnal animals that live in the canopy of trees in tropical rain forest. They are some of the least studied anteaters."We spent many months during 19 expeditions along South America over 10 years, searching for the little anteater," said Miranda. Intensive museum and laboratory efforts were also fundamental for the discovery."Four years ago we described a new tapir species from Brazilian Amazon, and now we have six new species of silky anteater. There are probably many more new species waiting for description in museums and in the wild, and they may be extinct before we have the chance to know them," said Fabrício Santos, geneticist and one of the co-authors of the study.These new species were just discovered, but their conservation status is already uncertain."Although silky anteaters in general are still widespread in the Amazon region, many of the new species may be under heavy pressure from deforestation, mining, and agriculture, among other threats," said Miranda, who is also head of the conservation NGO Projeto Tamandua, which is focused on conservation efforts for anteaters, sloths, and armadillos.
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New Species
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December 6, 2017
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https://www.sciencedaily.com/releases/2017/12/171206193754.htm
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New species of extinct marsupial lion discovered in Australia
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A team of Australian scientists has discovered a new species of marsupial lion which has been extinct for at least 19 million years. The findings, published in the
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Named in honour of palaeoartist Peter Schouten, The new species is about a fifth of the weight of the largest and last surviving marsupial lion, The discovery comes just a year after the fossilised remains of a kitten-sized marsupial lion were found in the same famous fossil site in Queensland. The UNSW scientists named that miniature predator With this new find, the researchers believe that two different species of marsupial lion were present in the late Oligocene at least 25 million years ago. The other, originally named This latest discovery reveals that the new species (According to the authors, these dental similarities distinguish Lead author Dr Anna Gillespie, a palaeontologist from the University of New South Wales (UNSW) in Sydney, Australia says that the latest finding raises new questions about the evolutionary relationships of marsupial lions: "The identification of these new species have brought to light a level of marsupial lion diversity that was quite unexpected and suggest even deeper origins for the family."
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New Species
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December 6, 2017
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https://www.sciencedaily.com/releases/2017/12/171206122512.htm
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Head start through human intervention: Study on the spread of European plant species on other continents
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More and more plant species are introduced to new areas through humans. Often, however, it is not clear which factors decide whether plants can permanently settle in their new environment. An international research team including Mark van Kleunen, ecology professor at the University of Konstanz, shows for the first time how ties to different habitats control the human-induced spread of European plant species on other continents. The research results have been published in the current issue of the scientific journal
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Several studies have clearly shown that the spread of animal and plant species through global trade has increased massively over the past few decades. Worldwide, over 13,000 plant species have been carried by humans to other regions, with more than 2,500 species being from Europe. By comparison: Only around 12,000 plant species are native to all of Europe, to Germany a bit more than 3,000 species."Our international team was the first to comprehensively investigate the role that the plants' ties to their native region play in their naturalization in other areas of the world. Our hypothesis was that this factor is decisive for the naturalization of plant species," explains Mark van Kleunen. The international research team documented the occurrences in different habitats for approximately 10,000 plant species originating from Europe -- from which more than 2,500 have naturalized on other continents. Subsequently the researchers studied whether plant species from certain habitats have spread particularly strongly on other continents.The result of the study was clear: Species from European habitats that have been highly changed by humans, such as fields and fallow land, were extremely successful in the conquest of other continents. So far, more than 40 percent of the plant species growing in these habitats in Europe have been established on other continents."Through colonization the Europeans have 'exported' many plants to other parts of the world." This often happened unintentionally -- for example through earth from ships or contaminated seed," explains Mark van Kleunen. He adds: "Plants native to European habitats changed by humans had a head start: They have been spread more often, and the living conditions in their new homes were ideal. The study shows that biological globalization particularly favours certain plant species -- namely those that have managed to naturalize in human-made habitats.
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New Species
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December 6, 2017
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https://www.sciencedaily.com/releases/2017/12/171206122451.htm
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Separated since the dinosaurs, bamboo-eating lemurs, pandas share common gut microbes
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A new study from North Carolina State University, the Smithsonian and Duke University finds that bamboo lemurs, giant pandas and red pandas share 48 gut microbes in common -- despite the fact that they are separated by millions of years of evolution.
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"The bamboo lemur's evolutionary tree diverged from that of both panda species 83 million years ago -- that's 18 million years before dinosaurs went extinct," says Erin McKenney, a postdoctoral researcher at North Carolina State University and lead author of a paper on the study. "These species are also separated by thousands of miles and the Indian Ocean. Red pandas and giant pandas aren't closely related either, with their most recent ancestor coming 47.5 million years ago. Lemurs are primates, red pandas are related to raccoons, and pandas are related to bears."Yet all three species share these 48 gut microbes -- more than 12 percent of the microbial types found in each species' gut," McKenney says. "The only common feature is their diet: all three species live almost exclusively on bamboo."Bamboo is not easy to eat. It is physically tough, difficult to break down, and is not especially nutritious. In order to thrive on a bamboo diet, an animal needs some help in breaking down the fibrous material to get the necessary nutrients. And that's especially true for animals with simple guts -- like the bamboo lemur, red panda and giant panda.To determine if there were microbes in common that may be essential to the success of these bamboo-eating species, researchers sampled feces from bamboo lemurs at Duke Lemur Center; giant pandas at the National Zoo; and red pandas at the Smithsonian Conservation Biology Institute. The researchers ran 100,000 genetic sequences per sample in an attempt to capture the full diversity of the gut microbiome for each species.Of the 48 microbes found in common, some are also found in other animals fond of fiber-rich diets. For example, several are also found in cows, and one is found in termites. This suggests that these microbes play a role in breaking down fiber to extract nutrients.In addition, the researchers compared the gut microbiome of the bamboo lemur to that of the closely related ringtail lemur -- and found only eight microbes in common."This really underscores the role that diet plays in determining what lives in our guts -- and, in turn, how these microbial ecosystems can shape the way animals live," McKenney says.
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New Species
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December 6, 2017
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https://www.sciencedaily.com/releases/2017/12/171206122555.htm
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It's good to be rare, for some species
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When most people think of rare species, they think of endangered ones that humans have caused to be rare through habitat loss, poaching, climate change and other disturbances. But some species have always been rare -- occurring in small densities throughout their range -- throughout their evolutionary history. Yet little is known about the traits that allow for them to be chronically rare and stay rare for long periods of time.
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A perspective paper from the University of California, Davis, in the journal The paper predicts what these traits might be and how having them could place chronically rare species at an advantage during crises."During great extinction events, almost every species will suffer," said author and paleontologist Geerat Vermeij, a professor with the UC Davis Department of Earth and Planetary Sciences. "The one that can withstand being rare and survive will have a real advantage during extinction events and crises. The question is, what enables a rare species to survive?"UC Davis evolution and ecology professor Rick Grosberg and Vermeij delved into this problem from an interdisciplinary perspective."Not all species have to have many individuals close to each other for the species to survive," said corresponding author Grosberg, director of the Coastal and Marine Sciences Institute at UC Davis. "The strategy for establishing viable populations is to consider how they reproduce."The authors predict rare species can have sustainable populations if:Other forms of rarity, like a limited range and a small population size for species that once were common, are not sustainable and could lead to extinction.Species unlikely to persist at low numbers for long periods of time:Sea urchins and abalone, for example, have a harder time recovering from population declines because their reproduction relies on broadcast spawning. The individuals become so far away from each other that the egg and sperm never unite, making reproduction in the wild nearly impossible.Knowing which traits enable species to be rare could help conservation managers better manage both rare and common species, and better design sanctuaries and preserves on land and at sea."By learning how a species can be rare, we can also learn how to protect species that cannot be rare," Vermeij said.'Little is known about rare species. They are notoriously difficult to sample since they are, by definition, rare. There also tends to be little funding available to study a handful of individual animals. The paper bluntly states that there are "virtually no reliable data to support our predictions" and calls for more research support on this topic. The authors note that, taken collectively, most species on Earth are likely rare, particularly in tropical rainforests.This perspective piece was inspired by observation, anecdote, and curiosity: Grosberg has seen the same soft coral under the same rock for the past 35 years while walking the coastline of Bodega Bay. A colleague who has walked the coastline south of Golden Gate Bridge for roughly the same time span knew of only two or three others. Grosberg had also seen a sea slug every couple of years while another colleague said he, too, had seen only one or two of them."You immediately start asking yourself, how do they do it? It has to be almost impossible to find a mate," Grosberg said. "Yet there they are. It makes you wonder."These stories tend to surface when those studying the natural world come together, signifying a potential role for citizen science to help fill in the gaps.The paper was supported in part by a grant from the National Science Foundation.
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New Species
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December 5, 2017
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https://www.sciencedaily.com/releases/2017/12/171205142546.htm
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Cooling climate drove evolution of Tasmanian Devil and its relatives
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A BIG drop in global temperatures 12-14 million years ago may explain the evolutionary success of Australia's unique marsupial carnivores, a new study has found.
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Tasmanian Devils, the cat-like Quoll and several shrew-like species are among 80 species of carnivorous marsupials called "dasyurids" which still inhabit parts of Australia and New Guinea.Now researchers from the Australian National University and the University of Salford in the UK have found evidence that while many rainforest-dwelling species died out as a result of the temperature drops, the Tasmanian Devil and its relatives adapted to the new drier woodland habitats.The scientists combined genomic data from living dasyurids and other marsupials with evidence from the fossil record to analyse how the group has diversified through time."This is the first time we've directly analysed genomic and fossil data in combination to look at dasyurid evolution" said co-author Robin Beck of the University of Salford, "and the pattern we found was striking: three of the four major dasyurid groups diversified almost simultaneously, immediately after this big temperature drop."The fossil record shows that many Australian marsupials went extinct during this period of intense climate change, with the environment becoming drier and colder, and wet rainforests being replaced by more open woodland environments.One group of Australian marsupials that suffered were the thylacines, which were also carnivorous and may have been competitors with the dasyurids."The loss of many species may explain why the dasyurids began to diversify rapidly during this period" said Beck, adding that future work will test whether dasyurids directly competed with thylacines.It is unclear what effect current climate change will have on Australian marsupials, but many living dasyurids are restricted to very small ranges and are threatened with extinction."If climate change leads to the loss of the kind of habitat these species need, then they may have nowhere else to go."
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New Species
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December 5, 2017
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https://www.sciencedaily.com/releases/2017/12/171205120026.htm
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Variation within species is critical aspect of biodiversity
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Concerns about biodiversity tend to focus on the loss of species from ecosystems, but a new study suggests that the loss of variation within species can also have important ecological consequences.
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Many species play important roles in nature and provide services important to people. For example, many fish species are harvested for food, and many insect species pollinate wild and cultivated plants. The loss of these species may mean the loss of ecosystem services, a major motivation for preventing species extinctions. The new study, published December 4 in "It's not just the loss of whole species that we should be concerned about. We also need to pay more attention to the ecological consequences of variation within species," said lead author Simone Des Roches, a postdoctoral researcher at UC Santa Cruz.Variation within species affects how organisms interact with each other and their surrounding environment. For example, the size of a fish's mouth, known as its gape, determines the size of prey it can eat. And the variety of noxious chemicals a plant produces controls which insects chew its leaves. Much of the time, traits like fish gape and leaf chemistry are adaptive. They help organisms live in a changing world. However, much less is known about how variation within species affects broader ecosystems.Variation within species can influence ecosystems through both direct and indirect ecological effects. Direct ecological effects can occur when trait differences affect the abundance or types of prey or resources an organism consumes, such as when the gape size of fish influences the kinds of plankton prey that survive in lakes or when leaf chemistry determines the grazing insects that inhabit a field. However, those prey or grazers often have diverse other interactions and roles in ecosystems that can be further altered. Ecological effects caused by such chains of interactions are known as "indirect effects."The study by Des Roches and her collaborators examined all available studies that compared the ecological effects of variation within species to the effects of species presence (removing the species or replacing it with another). They included 25 studies measuring a total of 144 different ecological responses from various types of plants, animals, and fungi. Their results show that variation within species, such as the effects of large- and small-gaped fish populations on zooplankton, are often similar to -- and can sometimes be stronger than -- species effects.On average, species tend to have larger effects on ecosystems. Yet over a third of studies examined showed that swapping different variants of the same species had similar ecological effects as removing that species entirely or replacing it with a completely different species."Traditionally, ecologists have focused on the ecological importance of biodiversity among species. This paper broadly establishes within-species biodiversity as critical for ecology," said coauthor Eric Palkovacs, associate professor of ecology and evolutionary biology at UC Santa Cruz.Nearly half of all the studies documented at least one ecological response that was more strongly affected by variation within species than by its presence. In a surprising result, within-species variation was shown to have the largest impacts on organisms that the focal species wasn't directly consuming or evading. In other words, trait variation within species appears most important for indirect effects.The study suggests that protecting trait variation within species is not only important for the future of evolution, but also potentially critical for the functioning of current and future ecosystems, according to Palkovacs. "This is a sobering thought given that human activity is causing within-species variation to be lost at a far greater rate than the extinction of entire species," he said.
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New Species
| 2,017 |
December 5, 2017
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https://www.sciencedaily.com/releases/2017/12/171205104211.htm
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World's heaviest bony fish identified and correctly named
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Japanese fish experts have identified and clarified the biological name of the world's heaviest bony fish ever caught. The 2,300 kilogram whopper is a
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Bony fish have skeletons made of bone rather than cartilage, as is the case for sharks or rays. Ocean sunfishes count among the world's largest bony fish, and have for centuries attracted interest from seafarers because of their impressive size and shape. Specimens can measure up to three meters (total length), and many weighing more than two thousand kilograms have been caught. Instead of a caudal fin, sunfish have a broad rudder-like lobe called a clavus.In this study, Sawai and his team referred to more than one thousand documents and specimens from around the world -- some of which date back 500 years. Their aim was to clarify the scientific names for the species of the genus Mola in fish.Ocean sunfishes can be classified into three species which Sawai's team temporarily called Mola species A, Mola species B, and Mola species C, respectively. Of the three species, the scientific name of Mola species C was officially named In this study, the researchers studied, dissected and measured 30 specimens of the remaining two Mola species (Mola species A and Mola species B) including fresh and preserved samples from different collections in the world. Information was obtained from photographs and from historic and recent records. The team set out specific morphological characteristics, and made notes on the distribution of the different species. This led them to conclude that the species names "For the same reason, we adopt the already proposed Japanese common name Ushi-manbo. 'Ushi' means 'cow', and refers to the head profile of the fish," Sawai explains.They also solved a case of mistaken identity. The Guinness World Records lists the world's heaviest bony fish as "Therefore, the world's heaviest bony fish that has been actually weighed and recorded to date is a specimen of
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New Species
| 2,017 |
December 4, 2017
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https://www.sciencedaily.com/releases/2017/12/171204150732.htm
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The Patterns of climate change
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Plant Ecology researchers at the University of Tübingen have developed a technique to monitor and predict how plant species will respond to climate change. Dr. Mark Bilton and Professor Katja Tielbörger, from the Institute of Evolution and Ecology, re-analysed data with Spanish collaborators from their unprecedented 16-year experiment. The experiment was conducted in an area the size of two football pitches within the Garraf National park south west of Barcelona. The landscape is mostly a Mediterranean scrubland, featuring thickets of low rise shrubs and herbs such as rosemary and thyme, and home to many protected species.
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Using large automatic shelters, climate for the plants living in their natural environment was changed in order to match climate conditions predicted in the future, separately by decreasing rainfall and by raising temperatures. However, until now, it was unclear how the different species of plants were responding to changed climate, making it difficult to make further predictions about which species may be most affected in the future. The results of the study were published in the In general, global warming and reduced precipitation may lead to large-scale species losses and vegetation shifts in ecosystems around the world. Depending on whether plants are better adapted to warm and dry conditions or to cool and wet conditions, the response to a changed climate is likely to vary even within a region. In the study the scientists showed, that within a region, the relative rate and direction of plant response to a changed climate can be directly related to where and which climates the species occur in more frequently.Therefore the researchers used a large online database containing the localities of where the different species in the experiment occurred all throughout southern Europe. These observations were combined with rainfall and temperature maps. This way the average temperature or rainfall requirements of the different co-occurring species in Spain could be used to rank them, based on which climates they are more commonly found. This ranking technique helped the scientists unlock the secrets behind which species were changing in the experiment, and monitor their changes over time.In this particular experiment, the overall species diversity and vegetative biomass did initially respond negatively, but from 8 to 16 years the overall amount of vegetation was increasing again. Here the researchers showed that the initial decrease was due to a disappearance of the wet adapted species, followed by a delayed increase in the dry loving species. In addition, the novel ranking technique showed, that the species that declined under decreased rainfall, were different to those disappearing under increased temperatures.By finding that responses were mainly related directly to where the species originally occur more frequently, separately for either rainfall or temperature, predictions can be extended to other future scenarios of climate change. "The technique is logical, but also surprisingly revealing," says Dr. Mark Bilton, who has been using the same method to study plant responses in Israel. "It allows us to compare the rate of change of species within a habitat, but also between habitats." Combining the ranking technique with the leading experimental approach to understanding climate change re-sponses, the response of vegetation in other regions can be monitored and compared. "Within a region this can aid conservation efforts to identify those species likely to be lost most quickly. We are also confident it can help identify, which species and regions around the world may be more vulnerable to climate change in the future."
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New Species
| 2,017 |
December 4, 2017
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https://www.sciencedaily.com/releases/2017/12/171204091719.htm
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Scientists track sharks by picking up DNA fragments from the sea
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Marine ecologists have shown that traces of DNA in the sea can be used to monitor shark populations.
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Current methods of baiting, hooking and filming sharks, rays and other large fish are invasive and costly and require teams of scientists spending much time at sea.Now a UK study, published in "Water contains minute fragments of the skin, excretions, blood of animals that have swum through there," explains Stefano Mariani, professor of conservation genetics at the University of Salford."It's just like when detectives do a forensic search of a crime scene, and can locate tissues and cells that contain the DNA of the suspects"Almost half of all known shark species are classified as 'data deficient', in part, because of the expense and complexity of finding the animals in the first place."The beauty of our method is that we can get a picture of shark diversity without the need for chasing, baiting and hooking them -- so it is a lot faster for conservation scientists and less traumatic for the animals," added Judith Bakker, the lead author of the study.The team, which included scientists from six countries, from Europe and the Americas, took water samples in four sites in the Caribbean and three in the Pacific Coral Sea. Using a process called metabarcoding, the team recovered significantly more shark DNA sequences in less anthropogenically impacted areas. In the Caribbean, the most diverse site was the Bahamas (a shark sanctuary) where 11 species were identified; in the Pacific, the samples from the remote, inhabited archipelago of Chesterfield proved to contain the largest amount of shark DNA .Bakker said: "To be able to glean so much information about these charismatic predators by simply sampling a few litres of water is truly astonishing.""Sharks are vulnerable to overfishing, often have slow growth rate and low fecundity, and therefore are a flagship species in marine conservation.And Professor Mariani believes this flexible and cheap new way of tracking sharks will help improve conservation: "In order to protect these elusive animals and their ecosystems, we must be able to rapidly assess many areas at repeated time intervals."eDNA should prove a big step forward because basically anyone can collect water samples, and every bottle of water is a potential gold mine of data.Of course much remains to be done to make the approach more effective: the molecular tools can be improved, so that every species of interest can be identified unambiguously; and finer-scale studies are required to understand the impact of oceanic currents and depth on the transport of trace DNA."
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New Species
| 2,017 |
December 4, 2017
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https://www.sciencedaily.com/releases/2017/12/171204091645.htm
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Surprise in the kangaroo family tree
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Ironically, it is jumping genes that indicate the need for a reorganization of the kangaroos' phylogenetic tree. According to a new study by a Senckenberg scientist, published recently in the journal "Scientific Reports," the swamp wallaby is more closely related to the remaining wallaby species and the large red and grey kangaroos and wallaroos than previously assumed. Together with her Australian colleagues from QUT in Brisbane, the researcher was the first to examine the relationships within the kangaroo genus Macropus on the basis of retrotransposons, genes that literally jump across the genetic material.
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Like their larger relatives, the kangaroos, the smaller wallabies are an iconic part of the fauna "down under." Even the Australian National Rugby Team is named after them. However, one wallaby stands out among the rest -- the swamp wallaby. It is the only marsupial that is able to switch to "turbo speed" during reproduction, becoming pregnant again before giving birth to the first set of offspring. The animal, which is widespread on the east coast of Australia, also differs from the other wallabies in its appearance, e.g., the shape of its teeth and its more crouched hop.Until now, the swamp wallaby was placed in its own genus, Wallabia, which only comprises one single species. However, this outsider role is actually not justified -- as recently shown by the molecular-genetic studies at the Senckenberg Biodiversity and Climate Research Centre."At the genetic level, the swamp wallaby does not represent a sister genus to the other wallabies, but it belongs to the genus Macropus, like all remaining wallaby species. Thus, it is not only more closely related to the other wallabies than previously thought, but also to Australia's icons, the large red and grey kangaroos and the wallaroos," explains Dr. Maria Nilsson, head of the study.Of all things, it was retrotransposons -- genes that literally jump across the genetic material -- that shed new light on the relationships among wallabies and kangaroos. These mobile genetic elements are able to make copies of themselves and reinsert these at a different location in the genome. If they occur in the same areas in different species, these species have a common ancestry.Nilsson elaborates: "Therefore, such jumping genes are also referred to as molecular fossils, which allow inferences on the phylogenetic history. They occur in almost all organisms; due to their properties, they have gained an increasing importance in evolutionary research in recent years."According to the analysis, the modern subgenera of the kangaroo genus Macropus as well as the swamp wallaby subsequently evolved from a common ancestor approximately five to seven million years ago. During this time period, the forests in Australia began to open up, many later being replaced by spreading grasslands. This habitat was colonized by new species of large red and grey kangaroos and wallaroos. "The wallabies and the swamp wallaby arose at a later date, and they inhabit woodlands," says Nilsson.Even in this genetic analysis, the swamp wallaby retains a special status. Although it now falls within the genus Macropus, it constitutes a subgenus within it -- and, not surprisingly, this subgenus only consists of one lone species.The research also still leaves some mystery to be solved as fellow researcher, Matthew Phillips, Associate Professor at the Queenland University of Technology points out in conclusion: "Although we show that the swamp wallaby clearly falls within Macropus, we also found some evidence for a small portion of it' s genome being a relic of an ancient, now extinct kangaroo. It might be interesting to investigate this further."
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New Species
| 2,017 |
November 30, 2017
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https://www.sciencedaily.com/releases/2017/11/171130141222.htm
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Bat cave study sheds new light on origin of SARS virus
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Genetic recombination between viral strains in bats may have produced the direct evolutionary ancestor of the strain that caused a deadly outbreak of severe acute respiratory syndrome (SARS) in humans, according to new research published in
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In late 2002, a SARS pandemic broke out in southern China, ultimately killing hundreds of people in dozens of countries by the summer of 2003. Scientists traced the outbreak back to horseshoe bats, hypothesizing that the culprit, SARS coronavirus, originated in these animals and then spread either directly to humans or to animals later purchased by humans at markets.However, the details of the outbreak's origin remain unclear. SARS strains found in bats are genetically distinct from the specific SARS strain that caused the outbreak, suggesting that known bat strains did not directly evolve into the outbreak strain.To address this issue, Ben Hu of the Chinese Academy of Sciences in Wuhan, China, and colleagues spent five years studying SARS viruses found in multiple species of horseshoe bats living in a single cave in Yunnan Province, China. In the new study, the researchers identified 11 new strains of SARS virus and sequenced their full genomes to uncover their evolutionary relationships.Genome analysis revealed that the newly identified bat strains, as well as several strains identified in a previous study of the same bat cave, contained all the essential genetic building blocks of the human SARS coronavirus. In some of the strains, for instance, portions of a gene known as the S gene showed high genetic similarity to the same regions found in the SARS coronavirus genome.Based on their genetic analysis, the researchers hypothesize that genetic recombination between precursor strains that later evolved into the newly identified strains may also have given rise to a strain that directly evolved into SARS coronavirus.Additional lab experiments showed that some of the newly identified bat strains are capable of entering human cells via the same cellular receptor employed by SARS coronavirus. This suggests that the bat cave contains strains that could potentially be directly transmitted to humans.Overall, these findings provide new insights into the evolutionary origin of SARS coronavirus. Because of the potential risk of existing bat strains spreading to humans, the researchers propose continued monitoring of the cave they studied, as well as other sites that may pose similar risk."Rhinolophus bats in China harbor genetically diverse SARS-related coronaviruses," the authors explain, "which may have given rise to the direct progenitor of SARS coronavirus after recombination."
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New Species
| 2,017 |
November 29, 2017
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https://www.sciencedaily.com/releases/2017/11/171129090421.htm
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Invasive frogs give invasive birds a boost in Hawaii
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Puerto Rican coqui frogs were accidentally introduced to Hawaii in the 1980s, and today there are as many as 91,000 frogs per hectare in some locations. What does that mean for native wildlife? Concerns that ravenous coquis could reduce the food available for the islands' native insect-eating birds, many of which are already declining, spurred researchers to examine the relationship between frog and bird populations -- but their results, published in
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Working at fifteen sites on the island of Hawaii in 2014, Utah State University's Robyn Smith, Karen Beard, and David Koons determined whether coquis were present at each site by listening for their calls at night and then estimated coqui density in invaded plots through a visual search. Bird surveys at all sites recorded 20 species, of which only 5 were native. To the researchers' surprise, native birds showed no response to coqui density or presence, but three of the nonnative species were more abundant in plots with coqui. The overall abundance of nonnative birds ranged from an average of 57 birds in coqui-free plots up to 97 where coqui density was highest.Coquis forage mostly in leaf litter, while Hawaii's native insect-eating birds forage mostly in canopy and understory, so perhaps they aren't in direct competition for insects. Nonnative birds may be getting a boost directly by eating adult or juvenile coquis, or indirectly through coqui's effects on the ecosystem -- coquis may alter nutrient cycling and even increase fly populations thanks to the extra biomass their excrement and carcasses create. "I was very surprised with the results for birds. It had been hypothesized before our study that coquis would compete with birds, particularly natives, because we know that coquis reduce insects where they invade," says Beard. "In retrospect, I guess it's not too surprising that predation is a more important interaction than competition -- that is a common finding in invaded systems -- but it was definitely not what we went in to test. The response that we see for Common Mynas and Red-billed Leiothrix is pretty convincing. We're pretty sure that some of this increase is due to these species eating live or dead coquis, and we're suggesting that some non-native birds are likely consuming coquis and this novel resource appears to be increasing their populations.""The findings presented in the study by Smith, Beard, and Koons, where abundances of some species of non-native birds in Hawaii are correlated with invasive coqui frogs, are very intriguing," according to the USDA's Aaron Shiels, an expert on invasive species in island ecosystems. "Furthermore, their interesting findings beg for future experimental manipulations that would uncover the causal factors that explain the patterns that they have observed."
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New Species
| 2,017 |
November 28, 2017
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https://www.sciencedaily.com/releases/2017/11/171128190033.htm
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There's a deeper fish in the sea
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The ocean's deepest fish doesn't look like it could survive in harsh conditions thousands of feet below the surface. Instead of giant teeth and a menacing frame, the fishes that roam in the deepest parts of the ocean are small, translucent, bereft of scales -- and highly adept at living where few other organisms can.
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Meet the deepest fish in the ocean, a new species named the Mariana snailfish by an international team of researchers that discovered it. The Mariana snailfish ("This is the deepest fish that's been collected from the ocean floor, and we're very excited to have an official name," said lead author Mackenzie Gerringer, a postdoctoral researcher at the University of Washington's Friday Harbor Laboratories. "They don't look very robust or strong for living in such an extreme environment, but they are extremely successful."Snailfish are found at many different depths in marine waters around the world, including off the coast of San Juan Island, where Gerringer is continuing research on the family of fish. In deep water, they cluster together in groups and feed on tiny crustaceans and shrimp using suction from their mouths to gulp prey. Little is known about how these fish can live under intense water pressure; the pressure at those depths is similar to an elephant standing on your thumb.This new species appears to dominate parts of the Mariana Trench, the deepest stretch of ocean in the world that is located in the western Pacific Ocean. During research trips in 2014 and 2017, scientists collected 37 specimens of the new species from depths of about 6,900 meters (22,600 feet) to 8,000 meters (26,200 feet) along the trench. DNA analysis and 3-D scanning to analyze skeletal and tissue structures helped researchers determine they had found a new species.Since then, a research team from Japan has recorded footage of the fish swimming at depths of 8,134 meters (26,686 feet), the deepest sighting so far."Snailfishes have adapted to go deeper than other fish and can live in the deep trenches. Here they are free of predators, and the funnel shape of the trench means there's much more food," said co-author Thomas Linley of Newcastle University. "There are lots of invertebrate prey and the snailfish are the top predator. They are active and look very well-fed."A handful of researchers have explored the Mariana Trench, but few comprehensive surveys of the trench and its inhabitants have been completed because of its depth and location, Gerringer explained. These research trips, conducted while Gerringer completed her doctorate at University of Hawai'i at M?noa, involved dropping traps with cameras down to the bottom of the trench. It can take four hours for a trap to sink to the bottom.After waiting an additional 12 to 24 hours, the researchers sent an acoustic signal to the trap, which then released weights and rose to the surface with the help of flotation. That allowed scientists to catch fish specimens and take video footage of life at the bottom of the ocean."There are a lot of surprises waiting," Gerringer said. "It's amazing to see what lives there. We think of it as a harsh environment because it's extreme for us, but there's a whole group of organisms that are very happy down there."Footage from the 2014 research cruise on R/V Falkor will also run in the BBC's "Blue Planet II" series, which is now airing in the U.K. The research team also filmed another new species on this cruise, the ethereal snailfish, living at great depths in the Mariana Trench. The Mariana snailfish's location was its most distinguishing characteristic, but researchers also saw a number of differences in physiology and body structure that made it clear they had found a new species. With the help of a CT scanner at the UW's Friday Harbor Laboratories, the researchers could look in close digital detail to study elements of the fish.The authors acknowledge the broad collaboration needed for deep-sea science, particularly in this discovery, and decided the new fish's scientific name should reflect that collaborative effort. The fish is named after a sailor, Herbert Swire, an officer on the HMS Challenger expedition in the late 1800s that first discovered the Mariana Trench.
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New Species
| 2,017 |
November 28, 2017
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https://www.sciencedaily.com/releases/2017/11/171128090948.htm
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A horse is a horse, of course, of course -- except when it isn't
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An international team of researchers has discovered a previously unrecognized genus of extinct horses that roamed North America during the last ice age.
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The new findings, published November 28 in the journal Prior to this study, these thin-limbed, lightly built horses were thought to be related to the Asiatic wild ass or onager, or simply a separate species within the genus Now named "The horse family, thanks to its rich and deep fossil record, has been a model system for understanding and teaching evolution. Now ancient DNA has rewritten the evolutionary history of this iconic group," said first author Peter Heintzman, who led the study as a postdoctoral researcher at UC Santa Cruz."The evolutionary distance between the extinct stilt-legged horses and all living horses took us by surprise, but it presented us with an exciting opportunity to name a new genus of horse," said senior author Beth Shapiro, professor of ecology and evolutionary biology at UC Santa Cruz.The team named the new horse after Richard Harington, emeritus curator of Quaternary Paleontology at the Canadian Museum of Nature in Ottawa. Harington, who was not involved in the study, spent his career studying the ice age fossils of Canada's North and first described the stilt-legged horses in the early 1970s."I had been curious for many years concerning the identity of two horse metatarsal bones I collected, one from Klondike, Yukon, and the other from Lost Chicken Creek, Alaska. They looked like those of modern Asiatic kiangs, but thanks to the research of my esteemed colleagues they are now known to belong to a new genus," said Harington. "I am delighted to have this new genus named after me. "The new findings show that At the end of the last ice age, both horse groups became extinct in North America, along with other large animals like woolly mammoths and saber-toothed cats. Although "We are very pleased to name this new horse genus after our friend and colleague Dick Harington. There is no other scientist who has had greater impact in the field of ice age paleontology in Canada than Dick," said coauthor Grant Zazula, a Government of Yukon paleontologist. "Our research on fossils such as these horses would not be possible without Dick's life-long dedication to working closely with the Klondike gold miners and local First Nations communities in Canada's North."Coauthor Eric Scott, a paleontologist at California State University San Bernardino, said that morphologically, the fossils of
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New Species
| 2,017 |
November 27, 2017
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https://www.sciencedaily.com/releases/2017/11/171127105922.htm
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New butterfly species discovered in Russia with an unusual set of 46 chromosomes
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What looked like a population of a common butterfly species turned out to be a whole new organism, and, moreover -- one with a very peculiar genome organisation.
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Discovered by Vladimir Lukhtanov, entomologist and evolutionary biologist at the Zoological Institute in St. Petersburg, Russia, and Alexander Dantchenko, entomologist and chemist at the Moscow State University, the startling discovery was named South-Russian blue ("This publication is the long-awaited completion of a twenty-year history," says Vladimir Lukhtanov.In the mid-nineties, Vladimir Lukhtanov, together with his students and collaborators, started an exhaustive study of Russian butterflies using an array of modern and traditional research techniques. In 1997, Alexander Dantchenko who was mostly focused on butterfly ecology, sampled a few blue butterfly specimens from northern slopes of the Caucasus mountains. These blues looked typical at first glance and were identified as Azerbaijani blue (However, when the scientists looked at them under a microscope, it became clear that they had 46 chromosomes -- a very unusual number for this group of the blue butterflies and exactly the same count as in humans.Having spent twenty years studying the chromosomes of more than a hundred blue butterfly species and sequencing DNA from all closely related species, the researchers were ready to ascertain the uniqueness of the discovered butterfly and its chromosome set.Throughout the years of investigation, it has become clear that caterpillars of genetically related species in the studied butterfly group feed on different, but similar plants. This discovery enables entomologists to not only discover new butterfly species with the help of botanic information, but also protect them."We are proud of our research," says Vladimir Lukhtanov. "It contributes greatly to both the study of biodiversity and understanding the mechanisms of biological evolution."
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New Species
| 2,017 |
November 24, 2017
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https://www.sciencedaily.com/releases/2017/11/171124084759.htm
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150 years of snake collections: Data bank proves rich snake diversity in the neotropics
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An international team made up of scientists from Brazil, Australia, USA, Ecuador, Germany and Sweden has published the results of an extensive database constructed for snakes of the American tropics. This database is made up of museum collections from the past 150 years and demonstrates that some Neotropical regions, such as the Cerrado in the central Brazil, contain a disproportionately high diversity. Furthermore, some other diverse regions are disproportionally under sampled, such as the Amazon. For the first time all factors, such as distribution patterns, collection records and frequency of occurrence are recorded from a total of 147,515 contributions to 886 snake species. Thus, the database covers 74 per cent of all snake species from 27 countries. The database, which has been so far unique in this form, will serve as a solid basis for conservation concepts, to biodiversity and evolution models in the future, as well as to design research agendas. The study was recently published in the journal "Global Ecology and Biogeography."
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About 10,500 species of reptiles (animals such as lizards and snakes) are found around the world and about 150 to 200 new species are also discovered every year. Snakes make up about 34 percent of this group of animals. "We assume that there are still many snake species that we still do not know. However, the identification of areas poorly-sampled, where probably new species can be found, must come from data and mapping of the known species" explains leading author Dr. Thaís Guedes from the University of Gothenburg and adds: "We realize that the very rich Amazonian area is, for example, one of the least explored areas -Most of the area is of high inaccessibility, the low investments in local research sum to relative shortage of experts to explore this huge area explain this result. Besides that, the centers of research, as scientific collections, are limited to the geographic area of major cities and universities."The international group of scientists have collected data about snake collections of the Neotropics -- South and Central America, the West Indies and the southern part of Mexico and Florida -- to record the diversity of snake species, their distribution, as well as their threats. The result is a unique database with 147,515 entries for 886 snake species from 12 families. Senior author of the study Alexandre Antonelli from the University of Gothenburg is pleased: "We have published one of the largest and most detailed surveys on the distribution of snakes -- one of the most species-rich reptile groups in the world! What an achievement!"The huge dataset is the result of a merger of a public database, which was examined by experts in the course of this study and the collection data of various international taxonomists.Another of the study's authors, Dr. Martin Jansen from the Senckenberg Research Institute in Frankfurt, says: "The review by taxonomic experts has greatly enhanced the data. One could say that the data bank now has a kind of quality mark, something like 'taxonomically verified'. This is very important, as biodiversity models often lack this in-deepth taxonomic expertise."The results from this most comprehensive and novel database also highlight the necessity to better sample, explore, and protect areas of high diversity, as well as rare species. "Our database provides the ideal basis, and it can now be used by other scientists (without taxonomic expertise) as a solid basis for subsequent models, for example, on evolutionary patterns or climate change effects," explains Guedes.
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New Species
| 2,017 |
November 24, 2017
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https://www.sciencedaily.com/releases/2017/11/171124084320.htm
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New species can develop in as little as two generations, Galapagos study finds
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The arrival 36 years ago of a strange bird to a remote island in the Galapagos archipelago has provided direct genetic evidence of a novel way in which new species arise.
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In this week's issue of the journal The study comes from work conducted on Darwin's finches, which live on the Galapagos Islands in the Pacific Ocean. The remote location has enabled researchers to study the evolution of biodiversity due to natural selection.The direct observation of the origin of this new species occurred during field work carried out over the last four decades by B. Rosemary and Peter Grant, two scientists from Princeton, on the small island of Daphne Major."The novelty of this study is that we can follow the emergence of new species in the wild," said B. Rosemary Grant, a senior research biologist, emeritus, and a senior biologist in the Department of Ecology and Evolutionary Biology. "Through our work on Daphne Major, we were able to observe the pairing up of two birds from different species and then follow what happened to see how speciation occurred."In 1981, a graduate student working with the Grants on Daphne Major noticed the newcomer, a male that sang an unusual song and was much larger in body and beak size than the three resident species of birds on the island."We didn't see him fly in from over the sea, but we noticed him shortly after he arrived. He was so different from the other birds that we knew he did not hatch from an egg on Daphne Major," said Peter Grant, the Class of 1877 Professor of Zoology, Emeritus, and a professor of ecology and evolutionary biology, emeritus.The researchers took a blood sample and released the bird, which later bred with a resident medium ground finch of the species In the current study, researchers from Uppsala University analyzed DNA collected from the parent birds and their offspring over the years. The investigators discovered that the original male parent was a large cactus finch of the species The remarkable distance meant that the male finch was not able to return home to mate with a member of his own species and so chose a mate from among the three species already on Daphne Major. This reproductive isolation is considered a critical step in the development of a new species when two separate species interbreed.The offspring were also reproductively isolated because their song, which is used to attract mates, was unusual and failed to attract females from the resident species. The offspring also differed from the resident species in beak size and shape, which is a major cue for mate choice. As a result, the offspring mated with members of their own lineage, strengthening the development of the new species.Researchers previously assumed that the formation of a new species takes a very long time, but in the Big Bird lineage it happened in just two generations, according to observations made by the Grants in the field in combination with the genetic studies.All 18 species of Darwin's finches derived from a single ancestral species that colonized the Galápagos about one to two million years ago. The finches have since diversified into different species, and changes in beak shape and size have allowed different species to utilize different food sources on the Galápagos. A critical requirement for speciation to occur through hybridization of two distinct species is that the new lineage must be ecologically competitive -- that is, good at competing for food and other resources with the other species -- and this has been the case for the Big Bird lineage."It is very striking that when we compare the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major, the Big Birds occupy their own niche in the beak morphology space," said Sangeet Lamichhaney, a postdoctoral fellow at Harvard University and the first author on the study. "Thus, the combination of gene variants contributed from the two interbreeding species in combination with natural selection led to the evolution of a beak morphology that was competitive and unique."The definition of a species has traditionally included the inability to produce fully fertile progeny from interbreeding species, as is the case for the horse and the donkey, for example. However, in recent years it has become clear that some closely related species, which normally avoid breeding with each other, do indeed produce offspring that can pass genes to subsequent generations. The authors of the study have previously reported that there has been a considerable amount of gene flow among species of Darwin's finches over the last several thousands of years.One of the most striking aspects of this study is that hybridization between two distinct species led to the development of a new lineage that after only two generations behaved as any other species of Darwin's finches, explained Leif Andersson, a professor at Uppsala University who is also affiliated with the Swedish University of Agricultural Sciences and Texas A&M University. "A naturalist who came to Daphne Major without knowing that this lineage arose very recently would have recognized this lineage as one of the four species on the island. This clearly demonstrates the value of long-running field studies," he said.It is likely that new lineages like the Big Birds have originated many times during the evolution of Darwin's finches, according to the authors. The majority of these lineages have gone extinct but some may have led to the evolution of contemporary species. "We have no indication about the long-term survival of the Big Bird lineage, but it has the potential to become a success, and it provides a beautiful example of one way in which speciation occurs," said Andersson. "Charles Darwin would have been excited to read this paper."
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New Species
| 2,017 |
November 22, 2017
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https://www.sciencedaily.com/releases/2017/11/171122093039.htm
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Species may appear deceptively resilient to climate change
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Nature itself can be the best defense against climate change for many species -- at least in the short term -- according to a study published in the journal
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The study found that natural habitats play a vital role in helping other plants and animals resist heat stresses ramping up with climate change -- at least until the species they depend on to form those habitats become imperiled. This suggests a need to re-evaluate climate change predictions for many species, including predictions that species in the south will move north with global warming.The work focused on the rocky shoreline stretching from California's Channel Islands to Washington's Olympic National Park, where low tides expose marine species to intense heat. It also has implications for habitats like grasslands and rainforests, which support millions of smaller species.Similar to how trees support birds and chipmunks, species like mussels and seaweed form habitat for other coastal species. They can lower temperatures so much for those other species that there is ultimately no difference in heat stress for sea creatures living in southern California versus northern Washington. If those habitats become suddenly imperiled, however, the species relying on them have little time to adapt."We might take for granted some of the resilience of our ecosystems because we don't realize how much they depend on these habitats," said lead author Laura Jurgens, who was a Ph.D. candidate at the UC Davis Bodega Marine Laboratory at the time of the study and is currently a postdoctoral researcher with Temple University and Smithsonian Institution. "For creatures that live in mussel beds and seaweed beds, it's like having a house with air conditioning at low tide. You can tolerate a lot of what goes on outside if you have air conditioning. But if you're looking at a future with more intense heat waves, and you don't have air conditioning anymore, you wonder, 'Where can I go?' For these species, they could make a big move north, but it won't help -- they still need these habitats to keep the heat in a tolerable range."The study indicates that plants and animals whose habitats serve as "ecological air conditioning" are not likely to move until the other species protecting them are threatened. This could make those species more vulnerable to sudden events like warm blobs of ocean water, disease, extreme storms or intense heat waves. These species may appear "deceptively resilient" to climate change until one event takes away their habitats.The study adds to the understanding of how different species respond to climate change. Scientists have observed some plants and animals under climate change are leaving lower latitudes for cooler ones. But this study shows that, for some species, habitat is more important than latitude in protecting them from the effects of climate change."If you're an octopus living in a mussel bed, the most important thing to keep your body temperature survivable is that mussel bed around you, not whether you live in Southern California, where it's warmer, or Washington," Jurgens said.The study also reinforces the benefits of habitat conservation. It indicates that destroying habitat can reduce climate resilience, while restoring and conserving habitat can help maintain biodiversity as the climate warms."People are really big compared to most organisms on the planet," Jurgens said. "We're enormous, and it's hard for us to understand what it's like to be in these habitats unless you imagine yourself in a place like a forest you walk into on a hot day. If that temperature is what you need to survive, that forest better be there."
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New Species
| 2,017 |
November 22, 2017
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https://www.sciencedaily.com/releases/2017/11/171122093122.htm
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Common jellyfish is actually two species, scientists find
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University of Delaware professor Patrick Gaffney and alumnus Keith Bayha, a research associate with the Smithsonian's National Museum of Natural History, have determined that a common sea nettle jellyfish is actually two distinct species.
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The Atlantic sea nettle is one of the most common and well known jellyfish along the U.S. East Coast, especially in the Chesapeake Bay and Rehoboth Bay where they commonly sting swimmers in large numbers. Since it was described nearly 175 years ago, the jellyfish has been assumed to be a single species.The discovery that is was actually two distinct species, Gaffney said, was made possible by DNA sequencing techniques."Before DNA came along, people in museums looked at organisms and counted spines and bristles, measured things, and sorted organisms by their physical characteristics in order to identify species," Gaffney said. "In the case of this jellyfish, which has been commonly known for centuries, Keith found through DNA sequencing that there were actually two groups."Turns out, the ocean-based sea nettle jellyfish is larger and has approximately 40 percent more tentacles (40, as compared to 24) than its bayside counterpart. The ocean sea nettle also has a larger bell, the top portion of the aquatic animal, while the tentacles are shorter than those in the bay nettle species.Bayha, the paper's lead author, earned his doctoral degree in biological sciences at UD in 2005. While at UD, he worked closely with Gaffney at the Hugh R. Sharp Campus in Lewes and, during fieldwork, collected jellyfish off the Delaware coast near Cape Henlopen. Bayha's interest in the species continued well after he completed his degree, and he's collected specimens everywhere from Norway to Brazil, and studied museum specimens from the Smithsonian, where he now works.Genetic testing of samples revealed differences in some of the sea nettle jellyfish. Working with Gaffney and Allen Collins from the National Oceanic and Atmospheric Association's National Systematics Laboratory, Bayha confirmed that there were actually two distinct species: an ocean-based species (Chrysaora quinquecirrha, "sea nettle") and a bay-based species (Chrysaora chesapeakei, "bay nettle") by comparing DNA data from the physical measurements of each species, and using statistical modeling to ask, "how good is the morphology for separating the species?""When you go back and pay close attention, you start counting the number of stinging cells and types, you see discrete differences that correspond to the DNA," said Gaffney. "In many cases, when we plotted the data, the graphs looked entirely different with no overlap, reaffirming that it was two species."The newly recognized of the species is the bay nettle, which is found in less salty waters called estuaries, such as the Chesapeake Bay. NOAA produces a daily jellyfish forecast for the Chesapeake Bay, where jellyfish blooms can sometimes become a nuisance. According to Gaffney, having two distinct species may explain why efforts to understand the factors that affect a jellyfish bloom are so difficult.The discovery also may be good news for the Eastern oyster, which is found on the Atlantic and Gulf Coasts and is the most widely consumed type of oyster. This is because bay nettle jellyfish eat harmless comb jellies called Mnemiopsis, a key predator to oyster larvae. If the bay nettles are effective at scooping up the Mnemiopsis, then the Eastern oyster larvae may have a better chance at survival.Interestingly, the new research showed that the bay nettle seems to be closely related to jellyfish found in coastal regions of Ireland, Argentina and Africa. But according to Bayha, it's not unusual that no one took notice of these differences before."It's not that I did anything that different, it's just that no one else looked for a very long time," Bayha said. "Jellyfish are something people don't pay attention to because they're fleeting. They come and go, are difficulty to study, and they don't have hard parts like shells that wash up on shore."
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New Species
| 2,017 |
November 21, 2017
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https://www.sciencedaily.com/releases/2017/11/171121123518.htm
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Twisted sex allows mirror-image snails to mate face-to-face, research finds
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A study led by the University of Nottingham has found that differently-coiled types of Japanese land snails should in fact be considered a single species, because -- against all odds -- they are sometimes able to mate, a result which has implications for the classification of other snails.
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Although most snails have a right-handed spiralling shell, rare 'mirror-image' individuals have a shell that coils to the left. This inherited condition has attracted attention because the genitals of so-called 'lefty' snails are on the opposite side of the head, and so it had been thought that normal 'face-to-face' mating is difficult or impossible.But the new research by Dr Angus Davison, and Paul Richards, a PhD student in the University of Nottingham's School of Life Sciences, published in the journal For many years, dextral (right-coiling) Euhadra aomoriensis and sinistral (left-coiling) Euhadra quaesita were believed to be two separate species because their mirror-image anatomy was thought to make it impossible for them to mate. However, the researchers found that the snails are sometimes able to twist their genitals into an appropriate position, and so mate in a normal face-to-face position. The common ancestry of the two types was also borne out by a comparison of the snails' genomes, or their genetic make-up, which also revealed the genetic similarities.Dr Davison said: "We were surprised to find that different-coiled individual Euhadra snails can sometimes mate, against expectations, and that there is evidence for this in their DNA. It was previously supposed that face-to-face mating was impossible between mirror image snails. We showed that while mating -- and the movement of genes -- between the two types is certainly a rare event, it occurs sufficiently often that the two types should properly be considered a single species. It turns out that the mating problem is mainly behavioural, requiring a twisting of the genitals, rather than a physical incompatibility."Collaborating scientists Professor Satoshi Chiba of Tohoku University said: "We were really surprised to find these reports from Japanese naturalists, of mating between sinistral and dextal snails, but in evolution even rare events can have quite large impacts on the underlying genes. As snails in general are sometimes classified into separate species based mainly on their shell-coiling, then this work has implications for the classification of other snail species."Dr Davison then said: "As it has previously been shown that the same sets of genes that make mirror image snails are also involved in making mirror image bodies in other animals -- including humans -- further research into the natural variation of snails could offer the chance to develop an understanding of how organs are placed in the body and why this process can sometimes go wrong."Chiral reversal in the Japanese snail genus Euhadra presents one of the best opportunities for scientists to investigate the possibility of two species having diverged from a single ancestor. Previously, two independent studies used mitochondrial DNA sequences to investigate the evolutionary history and genetic relationships between the sinistral and dextral Euhadra species -- but came up with quite different explanations.In this new study, the researchers used their network of mollusc experts and Japanese sources to investigate the potential evidence of possible matings between these two unlikely partners, uncovering five instances of this behaviour, including one observation of mating between the two different species -- sinistral E.quaesita and dextral E. senckenbergiana. They also used a more powerful method called RAD-seq to scan the DNA of sinistral and dextral individuals, which confirmed that there is movement of genes between the two types. In the future, the researchers would like to use the same methods to find the genes that make the snails mirror images, which may have implications for understanding the development of other animals, including ourselves.Dr Davison's lab and work on these mutant snails has made international headlines after he led a public campaign to find a sinistral mate for 'lefty' snail Jeremy, in the hope he could use any potential offspring to study the inheritance of this rare condition.The initiative has proved successful -- despite a tricky start in which the potential mates who were discovered mated with each other and produced offspring. Shortly before Jeremy's recent death, the snail was able to produce offspring with mate Tomeu, which will continued to be studied at Nottingham. Tomeu has recently been preserved as part of a bid to be included in the Sanger Institute's iconic 25 Genomes project, which would potentially help to uncover the DNA blueprint for these sinistral snails.The main part of this study was funded by a BBSRC studentship to Paul Richards, with additional funding from a BBSRC grant, the Japanese Society for the Promotion of Science, the Genetics Society, and the Daiwa Foundation.
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New Species
| 2,017 |
November 20, 2017
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https://www.sciencedaily.com/releases/2017/11/171120085428.htm
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Tiger bones? Lion bones? An almost extinct cycad? On-the-spot DNA checks at ports of entry
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Wildlife traffickers do their best to make animal and plant parts unidentifiable. When customs officials find bones, maybe all they can say, is that the bones belonged to large cats. Then they have to ask: are those tiger bones? Tigers are threatened with extinction and an international convention (CITES) forbids any trade of any parts. Or are those African lion bones? No parts from wild populations of African lions may be traded, but a global quota for captive-bred animals is still to be determined.
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With plants, something similar happens. It is hard to tell whether you're looking at an almost extinct encaphalartos cycad; or popular garden plants such as Asian cycas which look almost identical as seeds or seedlings.With pet fishes, how do you know if bits of invasive aquatic plants are coming in, as part of the import? Those plants can clog up reservoirs and dams when they escape the confines of their aquariums.Usually, a sample gets taken and sent to a laboratory somewhere to find out what animal or plant species is involved. That can take days. But if it is possible to rapidly analyse the DNA from the animal or plant part at the port of entry with portable gear and get a reliable result, a whole new range of enforcement responses become possible.On Monday November 20, 2017, the international Barcode of Life (iBOL) project presented its LAB-IN-A-BOX portable DNA barcoding kit, which makes rapid species identification possible for port of entry officials within a few hours.The launch took place during the 7th International iBOL conference at the Kruger National Park in South Africa, home to many threatened animals and plants, including rhinos, elephants and wild African dogs."We know that many of the species that share our planet are in serious decline -- from large vertebrates to small insects, from canopy trees to tiny understory plants. By coupling the power of DNA barcoding to identify species with portability, LAB-IN-A-BOX makes it possible for anyone to identify any species anywhere. It is certain to improve our capacity to care for the species that not only enliven our planet, but provide essential ecosystem services." said Prof Paul Hebert, Founder of the International Barcode of Life (iBOL) project and Director of the Centre for Biodiversity Genomics at the University of Guelph in Canada.In developing countries, where inspectors at ports of entry may have limited taxonomic knowledge and expertise, the need for rapid DNA identification is even more pressing, says Mr Sujeevan Ratnasingham, creator of LifeScanner and LAB-IN-A-BOX, Informatics Director at the Centre for Biodiversity Genomics, University of Guelph and the Chief Architect of the Barcode of Life Data Systems (BOLD)."Many threatened animals and plants are trafficked out of developing countries, which do not have adequate resources to combat these crimes. The aim of LifeScanner LAB-IN-A-BOX is to improve the situation by addressing two challenges, rapid detection, and successful prosecution. It does this by reducing the cost of adopting DNA analysis infrastructure and by simplifying usage of DNA analysis tools. It builds on the monumental work by the iBOL initiative in advancing DNA barcoding. The first implementation of LAB-IN-A-BOX is in South Africa's ports of entry," added Ratnasingham.LAB-IN-A-BOX depends on the BOLD database of reference DNA barcodes to compare samples to, says Prof Michelle van der Bank, Director of the African Centre for DNA Barcoding (ACDB) at the University of Johannesburg. "The ACDB works closely with iBOL to extend the BOLD database, particularly for plants and to do advanced DNA analyses. We will be training port of entry officials in Africa in the use of LAB-IN-A-BOX and will be a source of trained staff to advance this work," added Van der Bank.
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New Species
| 2,017 |
November 17, 2017
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https://www.sciencedaily.com/releases/2017/11/171117141732.htm
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eDNA tool detects invasive clams before they become a nuisance
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When seeking a cure for a disease, early detection is often the key. The same is true for eliminating invasive species. Identifying their presence in a lake before they are abundant is vital. A recent University of Illinois study successfully used environmental DNA to detect invasive clams in California and Nevada lakes. Researchers believe this tool can help identify pests before they become a problem.
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"Environmental DNA, or eDNA, means we're finding the DNA of an animal or plant that we're looking for from an environmental sample, like water," says U of I aquatic ecologist Eric Larson. "It's an emerging tool that has the potential to be better at detecting rare species in some cases, relative to some of our more traditional survey methods. There's a lot of DNA floating around in a lake or a stream, and if we can capture and identify it, it can tell us what organisms are present, including invasive species."Larson and colleagues from Rice University, the University of Notre Dame, and the University of Nevada at Reno developed a type of laboratory analysis called an eDNA assay to test for the presence of Larson says "The invasive clams even occur in Larson's backyard in Champaign, Illinois. "They're very distinctive and are hyper-abundant in central Illinois," Larson says. "If you see a lot of little white shells on the stream bed, those are probably The study, "Development and field validation of an environmental DNA (eDNA) assay for invasive clams of the genus
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New Species
| 2,017 |
November 17, 2017
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https://www.sciencedaily.com/releases/2017/11/171117103753.htm
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Using eDNA to identify the breeding habitat of endangered species
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Using wide-ranging eDNA analysis combined with traditional collection survey methods, Japanese researchers have identified the breeding site of critically endangered fish species Acheilognathus typus in the mainstream of Omono River in Akita Prefecture, Japan. The findings were published on November 14 in the online edition of
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Surveying aquatic organisms is a lengthy and laborious process, and covering a wide area also comes with high costs. Environmental DNA (eDNA) analysis provides a solution to these issues. In underwater environments such as lakes, reservoirs and rivers, we can find fragments of DNA drifting in the water from feces, skin or any other source of water-dwelling organisms. Analysis of eDNA is particularly effective for rare species such as For three days in August 2016 the team collected surface water samples from 99 locations, covering 112km of the Omono River, and extracted eDNA from the samples. They measured the DNA using a specific detection system for In the 99 locations of the Omono river surveyed, These findings demonstrate that in terms of cost and reliability, a combination of eDNA analysis and traditional collection methods is highly effective in identifying the habitats and breeding areas of rare species. The methods complement each other: the eDNA method is suited to surveying wide areas, while sample collection is very reliable for confirming species. This combination of methods could help to conserve this species by finding more breeding areas and establishing conservation areas. It could also be used for other rare and endangered species with a low population density spread across a wide area.
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New Species
| 2,017 |
November 16, 2017
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https://www.sciencedaily.com/releases/2017/11/171116132649.htm
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Production timings could stem illegal wildlife laundering
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The legal trade in captive bred animals and artificially propagated plants is often used by criminals to launder illegally collected wildlife. In many cases this is an easy way to bypass wildlife trade regulations as it can be very difficult for both buyers and customs officers to tell whether an item is of wild-origin.
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However, new research by Dr Dave Roberts in the School of Anthropology and Conservation at the University of Kent has shown that understanding the growth rates of species could help flag up when an item being sold could only have come from the wild, thus identifying it as illegal.Using information from those involved in the cultivation of orchids, Dr Roberts, working alongside Dr Amy Hinsley, a former PhD student now at the Department of Zoology at the University of Oxford, calculated the minimum likely times for different slipper orchids to be artificially grown.Using this data, they note that it should be possible for those monitoring illegal wildlife trade to spot when items are being offered for sale before they are likely to be legally available.By way of example, the research cites a new slipper orchid, The researchers note that similar production time frames could also help flag up animals being traded earlier than should be possible, such as newly discovered poison arrow frogs and chameleons.The hope is that the findings can be used to create a 'species watch list' so that law enforcement agencies and websites can spot when items are put up for sale.The findings have been published in the journal
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New Species
| 2,017 |
November 15, 2017
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https://www.sciencedaily.com/releases/2017/11/171115133853.htm
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Pacific Island countries could lose 50 -- 80% of fish in local waters under climate change
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Many Pacific Island nations will lose 50 to 80 percent of marine species in their waters by the end of the 21st century if climate change continues unchecked, finds a new Nippon Foundation-Nereus Program study published in
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"Under climate change, the Pacific Islands region is projected to become warmer, less oxygenated, more acidic, and have lower production of plankton that form the base of oceanic food webs," said lead author Rebecca Asch, Nereus Program alumnus and Assistant Professor at East Carolina University. "We found that local extinction of marine species exceeded 50 percent of current biodiversity levels across many regions and at times reached levels over 80 percent."The Pacific Islands region is the warmest of the global ocean. It's also an area where there is less seasonal variability -- it more or less feels like summer all year. Because there are no drastic seasons, the animals in the tropical Pacific may find changing conditions to be more of a shock."Additional warming will push ocean temperature beyond conditions that organisms have not experienced since geological time periods in this region," said co-author Gabriel Reygondeau, Nereus Fellow at UBC. "Since no organisms living in the ocean today would have time to adapt to these warmer conditions, many will either go extinct or migrate away from the western Pacific, leaving this area with much lower biodiversity."The authors examined the effects of climate change on more than a thousand species, including those that live on reefs and those that live in open-water habitats. Both groups underwent declines in local biodiversity, but the rates of decline were higher for the open-water species.These changes would be detrimental to Pacific Islanders, who are highly dependent on marine species for food, economic opportunities, and cultural heritage. Additional threats come from sea level rise and increasing major storms. Also, these are often developing countries with less resources available for societal adaptations to climate change."One hopeful point is that the extent of these changes in biodiversity and fisheries was dramatically reduced under a climate change scenario where greenhouse gas emissions were close to what would be needed for achieving the Paris Climate Agreement" said co-author William Cheung, Nereus Director of Science. "As a result, these changes in oceanic conditions are not inevitable, but instead depend on the immediate actions of all countries to materialize their commitment to limit greenhouse gas emissions as is being discussed in COP23 in Bonn, Germany, this week."
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New Species
| 2,017 |
November 14, 2017
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https://www.sciencedaily.com/releases/2017/11/171114123318.htm
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'Black box' methods used by biologists probably overestimate number of new species
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Do researchers need to "hit the brakes a little" before declaring a species is new to science?
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A recent University of Kansas study published in the peer-reviewed journal KU researchers assessed genetic differences between populations of Malaysian torrent frogs using two approaches: First, they employed species delimitation methods (SDMs) that focus on identification and demarcation of genetic breaks in targeted gene regions (DNA sequences) to determine species boundaries. Second, they used data gathered from across the genome to perform a comprehensive analysis of molecular variation -- to determine whether targeted gene studies reflect real "species."The new study, performed by doctoral student Chan Kin Onn and his adviser, KU Professor Rafe Brown, found that SDMs inferred up to seven separate species, while the more exhaustive analysis instead suggested the statistically justifiable existence of just three species, including various populations of the same frog species, which had a history of trading genes back and forth."SDMs were effective at delimiting divergent lineages in the absence of gene flow but overestimated species in the presence of marked population structure and gene flow," the authors wrote. Gene flow is the exchange of genes from one population to another -- such as exchange of genetic material among frogs living on different mountain ranges, facilitated by migration of individuals among populations."We're not calling into question analyses or methods of the past but, rather, we espouse a more cautious implementation and interpretation," said Chan Kin Onn, of KU's Biodiversity Institute and Department of Ecology & Evolutionary Biology, who led the new study. "We're not saying all those papers describing new species are wrong. I've described species using SDMs myself. But we suggest that, in some cases, we should be more cautious when describing new species, especially when gene flow among species is involved. Most of the available programs do not account for gene flow, so if genetic exchange is present, it's a no-brainer. We could easily get erroneous results. We suggest in this study that success is likely a matter of using the right tool for the right task."Chan and Brown's co-authors were L. Lee Grismer from La Sierra University, Yong-Chao Su of Kaohsiung Medical University in Taiwan, Jesse Grismer of Auburn University and UCLA, Evan Quah of Universiti Sains Malaysia and Alana Alexander of KU.The researchers performed their comparative analyses on populations of a group of Malaysian torrent frogs of the genus Amolops, all of which were initially believed to be of the same species."These torrent frogs are widely distributed across most of Asia," Chan said. "Previous studies treated them as 51 species. However, in Peninsular Malaysia, past analyses suggested there was only one species. Our study started when we surveyed the peninsula using methodology from our usual surveys -- we found these frogs in abundance in clean forest streams. They were so common we didn't pay them a lot of attention. Over time, however, we noticed that different populations looked strikingly physically different. We wondered if there could be more than one species in Malaysia."Chan decided to examine the torrent frogs using both commonly used SDMs and a more modern populations genomics approach to see if there was a difference between results."This was a methodological comparison study," Chan said. "I wanted to examine the efficacy of traditional approaches for identifying new species. I was motivated to do so because 'new species' are being described like crazy in Asia -- but most of these studies look at the same kind of data, use the same kind of analysis and employ an almost formulaic template in 'species delimitation' studies. However, most of these species delimitation approaches don't account for gene flow between populations -- a real, biological phenomenon. Because of this, species delimitation models may not properly fit studies of divergence when gene flow is present."The team analyzed 225 torrent-frog samples using morphological, mitochondrial DNA and genome-wide single-nucleotide polymorphism data to objectively find species boundaries while accounting for past and present gene flow between the frog populations."In today's age of genomic science, it's really important to look at genetic structure in finer detail," Chan said. "It's no longer sufficient to merely identify genetic 'breaks' between populations to justify their recognition as 'new species.' We also need to examine how genes are moving among populations and how that affects the integrity of species boundaries."Next, Chan will use the findings from Peninsular Malaysian torrent frogs as the basis to conduct a larger study on Malaysian karst geckos. He recently received a $19,500 grant from the National Science Foundation to test the hypothesis of ecological speciation in bent-toed geckos."The NSF Dissertation Improvement Grant program made my dissertation possible," Chan said. "It's a shame to learn the NSF discontinued the program this year. How will future U.S. scientists learn how to write NSF grant proposals?"Chan said his work on peninsular Malaysian torrent frogs was a "proof-of-concept" for his larger dissertation study with the geckos."I wanted to use genomic methods to see if they were able to accurately delineate cryptic species boundaries as a test run," Chan said. "It was hugely successful for a system of torrent frogs, which was thought to include only one species. Now, we're going to apply the same framework to a vastly different system, including those that potentially could be overdescribed."Chan's collaborative work with Lee Grismer of La Sierra University, spearheading research on geckos of Malaysia (Chan's home country), has helped to prioritize conservation efforts and even influenced landscape use and management plans related to quarrying karst formations in order to preserve a new, threatened species' habitat."One of the main reasons we're doing this is because we've found so many species on isolated karst formations, whose habitats are threatened by being ground up for cement," Chan said. "We have discovered and described new species that are already known to be under risk of extinction. This is because the only available habitat is being quarried for massive commercial cement production. We managed to halt one of these projects a few years ago. Some conservation organizations contacted us, saying, 'You guys have to come and survey our mountain -- the cement companies want to grind it down to dust.' We visited the sites and found new species of lizards found nowhere else on Earth -- and the cement company backed out."
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New Species
| 2,017 |
November 14, 2017
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https://www.sciencedaily.com/releases/2017/11/171114123310.htm
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Combating devastating amphibian disease
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Amphibian chytridiomycosis, caused by infection with the Batrachochytrium dendrobatidis fungus, is the most devastating vertebrate disease on record. The fungus infects more than 600 species of amphibian and has been implicated as the primary cause of decline in more than 200 species.
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A new "Crinia signifera appears to be an important player in maintaining levels of disease within the ecosystem," said lead author Dr. Laura Brannelly, of the University of Pittsburgh. "The common eastern froglet has a wide distribution in Australia and can occur in high densities. They co-occur in high numbers at the sites where other frog species have declined and may have played a key role in those declines."
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New Species
| 2,017 |
November 13, 2017
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https://www.sciencedaily.com/releases/2017/11/171113095619.htm
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A genus of European paper wasps revised for the first time using integrative taxonomy
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The European and Mediterranean species of the paper wasp genus Polistes were recently revised by scientists at the SNSB-Zoologische Staatssammlung München (ZSM).
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For the first time for this group scientists applied an integrative taxonomic approach which combines traditional morphological methods with modern DNA barcoding.As a result, the researchers were able to identify a new species from Morocco. For this well-researched wasp group, this is an actual sensation.The study is published in the open access journal The Munich researchers analysed more than 260 wasp specimens collected from across the study area with the help of DNA barcoding.They managed to identify all species and determine their distribution. In addition, based on the genetic data, they were able to evaluate morphological characters for each species and created a completely new key for identification.The wasps of the genus Polistes belong to the family Vespidae. The genus is represented by 17 species in Europe and the Mediterranean, with four species occurring in Germany. Within the genus, 13 species are social, with the queen overwintering and founding a new nest with up to 200 workers. Four species are parasitic and have no workers.Although Polistes has been well-known in Central Europe for more than 200 years, knowledge of Mediterranean species has so far been scarce. Many species of the genus exhibit only subtle morphological differences and show high levels of colour variation, further complicating their identification.An important result of this research is the separation of species of the Another very surprising result was the discovery of high levels of genetic variation within Polistes dominula, a species commonly found in Central Europe, indicating the presence of up to three different and hitherto unrecognized species -- a case requiring further investigation.Integrative taxonomy is an approach that combines different scientific methods to reliably differentiate species. In particular, DNA barcoding has proven to be a useful technique for the identification of species and for the discovery of new species. The method allows to identify most species quickly and accurately, even those species that are difficult to identify using traditional methods based on morphological characters.DNA barcoding uses a short gene fragment that differs in almost all species worldwide. The sequences are stored in an online database and can be used for identification. The method derives its name for being reminiscent of the barcodes similar to those found on products in supermarkets that allow quick and error-free identification at the checkout.DNA barcoding is part of a global research initiative led by the Canadian scientist Paul Hebert from the University of Guelph. The ZSM is a project partner and involved in assembling DNA barcodes of the German animal species. In addition to ZSM researchers, scientists from Switzerland and the Netherlands contributed to the Polistes project.
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New Species
| 2,017 |
November 13, 2017
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https://www.sciencedaily.com/releases/2017/11/171113095612.htm
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Now you see me! New insect mimics dead leaves -- but sings loud enough for humans to hear
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A new species of bushcricket which mimics dead leaves to the point of near invisibility and sings so loud humans can hear it has been examined for the first time using advanced technologies to reveal the unusual acoustic properties of its wings.
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Scientists investigating the newly-described species, named Usually the resonating call of a bushcricket is localised to the region where the sound originates, and is created by a plectrum on the right wing being plucked by a tooth-covered file on the left wing to produce sound vibrations. The plectrum is connected to a drum-like structure that works as a speaker to radiate and amplify the signal.Significantly, the research team from the University of Lincoln, UK, found that in The scientists also found that the females are larger than the males and also remain silent, with only the males employing their unusual acoustic abilities. Both sexes have wing regions that resemble damaged, discoloured leaves which provide excellent camouflage in the dense foliage of the South American rain forests, and are almost impossible to spot.In another twist on the conventional rules of nature, researchers also found that the bright orange spots, which sit at the base of the bushcricket's legs, are not to deter predators, but instead are likely to be involved in visual communication between the sexes. This is to be examined in future studies.To uncover the biophysical properties, behaviour and ecology of the species for the first time, undergraduate Zoology student Andrew Alexander Baker produced the anatomical description of the species using illustrations to infer the arrangement of veins in the insect's wing, and examined the sound producing structures of the wings in the males using advanced bioacoustics research techniques.The study was led by entomologist Dr Fernando Montealegre-Z from the University of Lincoln's School of Life Sciences. He said: "We wanted to find out more about this species, and we were very pleased to find an abundance of both sexes in the Cloud Forest of Colombia and Ecuador, something we had not been able to find before."To do this, we needed a keen ear and eye, and finding the animals proved to be particularly troublesome, so by listening to the males calling in the night and then locating them with a headtorch, we knew we were close to the females as well."We had to have a great deal of luck and patience as the females don't sing, but we eventually managed to uncover three females as they are attracted by the calls of the males and will walk towards them. These three females then finally gave us the missing data to be able to properly describe these amazing animals as a new species."The unusual whole-wing-resonance might partly explain why the male's song is particularly loud and also in the range audible to the human ear, while its closest relatives are all singing at higher frequencies which we cannot detect with our ears."Using a combination of tools from classical morphology to the-state-of-the-art bioacoustics and laser Doppler vibrometry, we have now been able to describe this species for the first time, and our approach gives fresh air to classical taxonomy."The findings have been published in the
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New Species
| 2,017 |
November 8, 2017
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https://www.sciencedaily.com/releases/2017/11/171108131836.htm
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Seagrass biodiversity is both a goal and a means for restoration
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Coral reefs, seagrass meadows and mangrove forests work together to make the Coral Triangle of Indonesia a hotspot for marine biodiversity. The system supports valuable fisheries and endangered species and helps protect shorelines. But it is in global decline due to threats from coastal development, destructive fishing practices and climate change.
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A UC Davis study published recently in the journal The Coral Triangle is home to about 15 species of seagrasses, more than almost anywhere else on Earth. Previous seagrass restoration efforts have primarily focused on a single species.For this study, the scientists transplanted six common seagrass species at four species-richness levels: monocultures, two, four, and five species. They analyzed how well the initial transplants survived and their rate of expansion or contraction for more than a year. The results showed that planting mixtures of diverse seagrass species improved their overall survival and growth."Seagrass beds are important habitats for fisheries species, for protecting shorelines from storm damage, and they provide livelihoods for many millions of humans around the world," said Susan Williams, a professor in the UC Davis Department of Evolution and Ecology and the UC Davis Bodega Marine Laboratory. "Seagrass habitat is being lost at a rate of a football field's area every half-hour, which threatens these important functions. We demonstrated we could improve seagrass restoration success by planting a mix of species, and not just a single species, which has been the common restoration practice in warm regions such as Florida, Texas, and also in Indonesia, where we performed the experiment."
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New Species
| 2,017 |
November 7, 2017
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https://www.sciencedaily.com/releases/2017/11/171107150704.htm
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Rival sperm and choosy eggs: When sperm compete , eggs have a choice
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The delicately mannered dance between discerning eggs and vying sperm is more complicated than scientists once believed, and it may hold secrets about the evolution of new species.
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In a paper published in the journal When it comes to sea urchins at least, the answer is yes.Using sea urchin populations off the Pacific coast of Canada, Levitan set out to determine the degree to which, among marine animals using external fertilization, sperm from multiple males compete to fertilize individual eggs. Sea urchins are considered a good model species for scientists as they seek to better understand marine organisms because the spiny animals can be easily induced to spawn.That makes them perfect for the study of fertilization and compatibility."Patterns of fertilization and the evolution of reproductive compatibility are important processes for marine organisms," Levitan said. "They are mechanisms that can drive the development of new species,"In nature, sea urchins release clouds of sperm and eggs that fertilize while floating in the water. In this study, Levitan induced males to spawn and then collected tiny parcels of seawater -- enough for a population of sperm to immediately interact with an egg -- in syringes stocked with scores of unfertilized eggs.Later, Levitan conducted paternity analyses on the newly fertilized eggs in order to detect the number of individual males' sperm present in the samples. His findings defied his expectations: Sperm from multiple males were competing to fertilize single eggs, and the eggs appeared to be choosing their preferred mate from among the crowd."While we expected to find that single eggs generally encounter sperm from a single male, we found that eggs are often simultaneously encountering sperm from more than one male in the brief interval between sperm contact and fertilization," Levitan said. "This is the first evidence that sperm from different males compete for the same egg, which indicates an opportunity for eggs to have a choice."When sperm cells suspended in the ocean are searching for a favorable mate, they rely on a surface coat of recognition proteins to bind to and fertilize receptive eggs.According to a traditional understanding of selection processes, the sperm with more effective proteins should be selected for systematically, whereas sperm with less effective proteins, with their inferior fitness for fertilization, should be quickly culled from the gene pool.However, it's often the case that sperm with less effective recognition proteins are actually more likely to successfully fertilize an egg."It's a little puzzling," Levitan said. "One would think that within a species, the most compatible protein should always be selected. So why do we consistently see variation in the effectiveness of these proteins in the population?"The answer to this question might be found in an evolutionary call and response between temperamental sperm and egg cells.In past research, Levitan has found that less compatible proteins can be favored when sperm are so abundant that there is a risk of multiple sperm fertilizing an egg, a fatal process called polyspermy. Because less compatible sperm are less likely to inundate and kill an egg, eggs might evolve lower compatibility surfaces to avoid polyspermy. In turn, sperm may then evolve to match these new egg surfaces. This can produce a mixture of sperm and egg compatibility types that sets the stage for sperm competition and egg choice.When sperm from multiple males arrive at an egg concurrently, eggs are able to choose the sperm whose recognition proteins are best suited for healthy fertilization. This selection process can spur the evolution of new recognition proteins, eventually resulting in reproductive isolation and, in some cases, the creation of new species altogether."Sexual selection within a species can cause variation in recognition proteins, and that can lead to assortative mating, where only certain types mate with other certain types," Levitan said. "If you have assortative mating and you have disruptive selection, where individuals who cross over to a different type don't do very well, that can eventually generate reproductive isolation and speciation."These processes are critical for marine species that use external fertilization, the major mode of reproduction in the ocean. But Levitan believes scientists may soon find sperm competition and egg choice are equally important for internal fertilizers like mammals."These are the sort of sperm and egg cell interactions that drive divergence among populations, within populations and among species," Levitan said. "What I'm hoping is to generate interest in these interactions so we can better understand how general they are for both internally and externally fertilizing species."This research was funded by the National Science Foundation.
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New Species
| 2,017 |
November 2, 2017
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https://www.sciencedaily.com/releases/2017/11/171102121134.htm
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Newly discovered orangutan species is 'among the most threatened great apes in the world'
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Scientists have long recognized six living species of great ape aside from humans: Sumatran and Bornean orangutans, eastern and western gorillas, chimpanzees, and bonobos. But researchers reporting in
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Unfortunately, the researchers say, there are only about 800 Tapanuli orangutans left. Those that remain are also under threat from loss of lowland habitat and hunting, which makes this newly discovered species among the most threatened great ape species in the world."It isn't an everyday event that we find a new species of great ape, so indeed the discovery is very exciting," said Michael Krutzen of the University of Zurich in Switzerland, senior author of the study."Great apes are among the best-studied species in the world," added Erik Meijaard of the Australian National University. "If after 200 years of serious biological research we can still find new species in this group, what does it tell us about all the other stuff that we are overlooking: hidden species, unknown ecological relationships, critical thresholds we shouldn't cross? Humans are conducting a vast global experiment, but we have near-zero understanding of what impacts this really has, and how it could ultimately undermine our own survival."The new orangutan species lives in the Batang Toru area in North Sumatra, Indonesia. While there had been rumors, no one was sure that this population of orangutans existed until 1997. They live south of what had been the known range for Sumatran orangutans.Earlier studies suggested that the group differed from other orangutans behaviorally and at the genetic level, but it wasn't clear that those differences were enough to support its designation as a new species. The breakthrough came in 2013, when the research team including Meijaard got access to a skeleton belonging to a Batang Toru orangutan killed in a human-animal conflict. Careful studies of the animal revealed consistent differences in its skull and teeth.A sophisticated analysis of 37 orangutan genomes now shows that the deepest split in the evolutionary history of living orangutans occurred more than three million years ago, between the Batang Toru population and Bornean orangutans to the north of Lake Toba. Bornean and Sumatran orangutans separated only much later, less than 700,000 years ago. Behavioral and ecological evidence lends further support for the notion that the orangutans living in Batang Toru are a separate species, the researchers said."The Batang Toru orangutans appear to be direct descendants of the initial orangutans that had migrated from mainland Asia, and thus constitute the oldest evolutionary line within the genus Pongo," said Alexander Nater, also of the Unversity of Zurich. "The Batang Toru population was connected to populations to the north until 10,000 or 20,000 years ago, after which it became isolated."The findings mean that there are now 800 fewer Sumatran orangutans than previously thought. The Tapanuli orangutans are also severely threatened by hunting and the proposed development of a hydroelectric dam that would flood large parts of their best habitat if implemented. That's especially discouraging given that previous analyses suggest a mortality rate of less than one percent per year would still be enough to drive the Tapanuli orangutans extinct."If even 8 out of 800 animals per annum were killed or otherwise removed from the population, the species might be doomed," the scientists caution.The researchers say the most important thing now is to work with organizations already in the area and Indonesian government authorities to urge support for more effective conservation measures to protect the Batang Toru area. They also want to learn more about the relationship of the Tapanuli orangutan to now-extinct orangutan populations that used to live in other parts of Sumatra.
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New Species
| 2,017 |
November 2, 2017
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https://www.sciencedaily.com/releases/2017/11/171102095923.htm
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The secret lives of ancient land plants
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The clues to our evolutionary ancestors? They're in our genes.
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All organisms carry patterns in their DNA that scientists can analyze to decipher where and when a species diverged on the evolutionary tree. These studies can reveal how a particular species evolved to become the organism we know today.In collaboration with over 40 universities and research institutes worldwide, Takayuki Kohchi and colleagues at Kyoto University have unraveled the genome of the common liverwort -- "All land plants, from moss on rocks to trees that flower, evolved from a common ancestral algal species that colonized land about 500 million years ago," explains Kohchi. "The liverwort diverged from other land plants at the earliest stage of evolution, and therefore still possess ancestral characteristics of plant species that followed."Liverworts have been used extensively in plant research since they were first studied in the late Middle Ages. In the past few years, Kohchi and his colleagues had developed various molecular and genetic techniques that opened the door to improved analysis, especially for the study of plant genetics.Using these techniques, the team deciphered the liverwort's roughly 20,000 genes, discovering in part the low level of genetic redundancy that controls the plant's development and physiology."Flowering plants have redundant copies of vital genes in their DNA, so that if something goes wrong, there's a backup," continues Kohchi. "And while liverworts have the fundamental ancestral versions of basic mechanisms to keep plants alive, these are exceedingly simple."Based on these findings, the scientific significance of the lowly liverwort is now unassailable: it is a key model plant for molecular and genetic studies, providing hints to future agricultural applications and plant breeding technologies."Now that we know the liverwort genome, we can begin to decipher the functions of each individual gene, and how these evolved in later plant species," concludes Kohchi.
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New Species
| 2,017 |
November 1, 2017
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https://www.sciencedaily.com/releases/2017/11/171101141709.htm
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Winners and losers of forest fragmentation
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Breaking up the rainforest into small, isolated patches is forcing more species to live at the forest edge and putting those that are dependent on the forest core at risk.
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Research published today in the academic journal Collecting data for over 1,500 forest vertebrates, the research team led by Newcastle University, UK, and Imperial College London, found that 85% of species are now being impacted by this forest fragmentation.The winners are those that seek out the forest edge while the losers are those that rely on the forest core and whose habitat is being constantly squeezed.Developing a system to predict which species are likely to disappear first from our changing forest habitats, the team is now hoping to use this information to inform forest conservation and restoration efforts.Dr Marion Pfeifer, lead author now based at Newcastle University, explains:"Tropical forests and the animals they harbour are being lost at alarming rates but in order to protect them we need to know exactly how fragmentation of the land is impacting on the animals that live there."This is critical for the hundreds of species that we identified as being clearly dependent on intact forest core areas -- that is forest which is at least 200-400m from the edge. These include species such as the Sunda pangolin (Manis javanica), the Bahia Tapaculo (Eleoscytalopus psychopompus), the Long-billed Black Cockatoo (Zanda baudinii) and Baird's tapir (Tapirus bairdii)."These species were highly sensitive to the changing habitat and therefore more likely to disappear in landscapes that encompass only a small proportion of intact forest."Half the world's forest habitat is now within 500m of a 'forest edge' due to the expansion of road networks, logging, agriculture and other human activity. These edges look different to the rest of the forest: with more light, less moisture and generally higher temperatures.Using species' abundance data collected from fragmented landscapes worldwide, the team analysed 1,673 species of mammals, birds, reptiles and amphibians to see how they respond to edges.Using new spatial and statistical analyses developed at Imperial College London, they were able to show that 85% of species' abundances are affected, either positively or negatively, by forest edges.More importantly, edge effects create species communities near edges that bear little resemblance to the communities of forest interiors, and this species turnover likely reflects dramatic changes to the ecological functioning of modified forest habitats.Robert Ewers, Professor of Ecology at Imperial College London, explains:"About half of species win from the forest change; they like the edges and so avoid the deep forest, preferring instead to live near forest edges."The other half lose; they don't like the edges and instead hide away in the deep forest. The winners and losers aren't equal though. Some of the species that like edges are invasive like the boa constrictor, while the ones huddled into the deep forest are more likely to be threatened with extinction -- like the Sunda pangolin.""Our analysis allows us to track species' abundances in response to edge effects to predict the impact on biodiversity caused by forest loss and fragmentation," adds Dr Pfeifer."This is useful for land management and as a tool to help guide our conservation efforts. The next step is to use this data and our software to allow managers to create 'optimal landscapes' that combine forest use with biodiversity conservation."
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New Species
| 2,017 |
November 1, 2017
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https://www.sciencedaily.com/releases/2017/11/171101141508.htm
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Newly described giraffid species may help trace evolution of giraffe ancestors
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A new giraffid species from Spain may extend the range and timespan of the ancestors of giraffes, according to a study published November 1, 2017 in the open access journal
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The giraffids, a family of ruminants that includes modern day giraffes and okapis, are thought to have existed as far back as the early Miocene epoch. While fossils from over 30 extinct species have been described, the lack of fossilised skulls has been a barrier to determining evolutionary relationships.The authors of the present study describe a new large giraffid species, named Decennatherium rex sp. nov., from the Spanish province of Madrid. The fossilized skeleton is thought to date from the late Miocene and is unusually complete, providing the researchers with new anatomical and phylogenetic data.The authors conducted a phylogenetic analysis to help elucidate evolutionary patterns. The results suggest that the Decennatherium genus may have been the most basal branch of a clade of now-extinct giraffids containing both sivatheres, the largest known giraffids, and samotheres, whose appearance was somewhere in between that of okapis and giraffes. All giraffids in this group feature four horn-like skull protuberances known as ossicones, two over the eyes and two larger ridged ossicones at the back of its head. The authors state that Decennatherium was likely the earliest-evolving example of this ossicone layout.The inclusion of Decennatherium in the sivathere-samothere clade would extend its timespan back to the early late Miocene and its range as far as the Iberian peninsula, making the clade one of the most successful and long-lived of all the giraffids.As Ríos summarizes: "New four horned extinct giraffid Decennatherium rex from Cerro de los Batallones (9my, Madrid) sheds light on the evolution of the giraffid family and the extinct giant Sivatherium."
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New Species
| 2,017 |
October 25, 2017
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https://www.sciencedaily.com/releases/2017/10/171025140503.htm
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Alvarezsaurid dinosaur from the late Cretaceous found in Uzbekistan
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Bones from an Alvarezsaurid dinosaur were discovered in Uzbekistan and could shed light on the evolution and origin of the species, according to a study published October 25, 2017 in the open-access journal PLOS ONE by Alexander Averianov of Zoological Institute of the Russian Academy of Sciences, Russia and Hans-Dieter Sues of the Smithsonian Institution, USA.
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Previous studies have described Alvarezsauridae as small, long-legged, bipedal dinosaurs with short forelimbs that featured bird-like hands. Since Alvarezsaurid remains are extremely rare, there is plenty to learn about the evolution of this species.The authors of this study analyzed previously excavated Alvarezsaurid remains from the Turonian Bissekty Formation of Uzbekistan. They examined the vertebrae, the bird-like bone that fuses the wrist and knuckle known as the carpometacarpus, and pieces of what would be the fingers or toes, known as the phalanx. They then measured and compared the shapes and sizes of these bones with those from similar species from the literature.The authors state that the characteristics for the Alvarezsaurid bones are so distinctive that it could be identified just from the seven bones collected at the Bissekty Formation. These distinctive features included rounded vertebrae located close to the tail, a large and depressed second metacarpal, and a robust second digit with a claw-like end.While there are competing theories about where the Alvarezsaurid originated, the authors suggest that the discovery of an Alvarezsaurid at this site in Uzbekistan indicates that this group had an evolutionary history in Asia and provides evidence that this continent could have been where the clade originated.Lead author Hans Sues says: "Our paper reports the discovery of the earliest known alvarezsaurid dinosaur from the Northern Hemisphere, based on 90-million-year-old fossils from Central Asia. Alvarezsaurids were unusual small predatory dinosaurs that had very short but powerfuly built arms that ended in a single large digit."
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New Species
| 2,017 |
October 25, 2017
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https://www.sciencedaily.com/releases/2017/10/171025103146.htm
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Marine species threatened by deep-sea mining
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Less than half of our planet's surface is covered by land. The rest is water, and this environment is home to an enormous range of animal species, most of which remain undiscovered and thus have not yet been named.
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A newly discovered species, 'Modern society, with its power lines and advanced batteries, has a great need for cobalt, nickel and copper, metals found in high concentrations in so-called polymetallic nodules on the Pacific seafloor in the Clarion-Clipperton Zone,' says Thomas Dahlgren from the Department of Marine Sciences, University of Gothenburg.The sponge Plenaster craigi must filter the water to find small particles with nutrients and energy that after being formed at surface level several kilometres above have slowly fallen down to the bottom.'There is not a whole lot of material that makes it all the way to the bottom. Most of it gets eaten by zooplankton and small fish on its way down and is returned to the food web in the ocean's upper sunlit layer. Consequently, Plenaster craigi must filter large amounts of water to survive. This makes it vulnerable to the sand and mud stirred up when the nodules are harvested and pumped the 4,000 metres to the collection barges waiting at the surface,' says Dahlgren.Since 2013 when the sponge was first discovered, the species has temporarily been referred to as Porifera sp. A. Following the recent species description (see link to the article below), the sponge has now been assigned a permanent name, Plenaster craigi is the only known species of the newly defined genus Plenaster, which means 'many stars'. Craigi was included in the name to honour Professor Craig Smith at the University of Hawaii, who led the two expeditions during which the animal was first discovered and collected.The new species can now be used to explore how deep-see mining of minerals affects an environment that has not been touched for billions of years.Thomas Dahlgren from the University of Gothenburg's Department of Marine Sciences in Sweden and Uni Research in Norway participated in the study together with researchers from the National University of Singapore and the Natural History Museum in London.
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New Species
| 2,017 |
April 29, 2021
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https://www.sciencedaily.com/releases/2021/04/210429133929.htm
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Fish have been swallowing microplastics since the 1950s
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Forget diamonds -- plastic is forever. It takes decades, or even centuries, for plastic to break down, and nearly every piece of plastic ever made still exists in some form today. We've known for a while that big pieces of plastic can harm wildlife -- think of seabirds stuck in plastic six-pack rings -- but in more recent years, scientists have discovered microscopic bits of plastic in the water, soil, and even the atmosphere. To learn how these microplastics have built up over the past century, researchers examined the guts of freshwater fish preserved in museum collections; they found that fish have been swallowing microplastics since the 1950s and that the concentration of microplastics in their guts has increased over time.
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"For the last 10 or 15 years it's kind of been in the public consciousness that there's a problem with plastic in the water. But really, organisms have probably been exposed to plastic litter since plastic was invented, and we don't know what that historical context looks like," says Tim Hoellein, an associate professor of biology at Loyola University Chicago and the corresponding author of a new study in Caleb McMahan, an ichthyologist at the Field Museum, cares for some two million fish specimens, most of which are preserved in alcohol and stored in jars in the museum's underground Collections Resource Center. These specimens are more than just dead fish, though -- they're a snapshot of life on Earth. "We can never go back to that time period, in that place," says McMahan, a co-author of the paper.Hoellein and his graduate student Loren Hou were interested in examining the buildup of microplastics in freshwater fish from the Chicagoland region. They reached out to McMahan, who helped identify four common fish species that the museum had chronological records of dating back to 1900: largemouth bass, channel catfish, sand shiners, and round gobies. Specimens from the Illinois Natural History Survey and University of Tennessee also filled in sampling gaps."We would take these jars full of fish and find specimens that were sort of average, not the biggest or the smallest, and then we used scalpels and tweezers to dissect out the digestive tracts," says Hou, the paper's lead author. "We tried to get at least five specimens per decade."To actually find the plastic in the fishes' guts, Hou treated the digestive tracts with hydrogen peroxide. "It bubbles and fizzes and breaks up all the organic matter, but plastic is resistant to the process," she explains.The plastic left behind is too tiny to see with the naked eye, though: "It just looks like a yellow stain, you don't see it until you put it under the microscope," says Hou. Under the magnification, though, it's easier to identify. "We look at the shape of these little pieces. If the edges are frayed, it's often organic material, but if it's really smooth, then it's most likely microplastic." To confirm the identity of these microplastics and determine where they came from, Hou and Hoellein worked with collaborators at the University of Toronto to examine the samples using Raman spectroscopy, a technique that uses light to analyze the chemical signature of a sample.The researchers found that the amount of microplastics present in the fishes' guts rose dramatically over time as more plastic was manufactured and built up in the ecosystem. There were no plastic particles before mid-century, but when plastic manufacturing was industrialized in the 1950s, the concentrations skyrocketed."We found that the load of microplastics in the guts of these fishes have basically gone up with the levels of plastic production," says McMahan. "It's the same pattern of what they're finding in marine sediments, it follows the general trend that plastic is everywhere."The analysis of the microplastics revealed an insidious form of pollution: fabrics. "Microplastics can come from larger objects being fragmented, but they're often from clothing," says Hou -- whenever you wash a pair of leggings or a polyester shirt, tiny little threads break off and get flushed into the water supply."It's plastic on your back, and that's just not the way that we've been thinking about it," says Hoellein. "So even just thinking about it is a step forward in addressing our purchases and our responsibility."It's not clear how ingesting these microplastics affected the fish in this study, but it's probably not great. "When you look at the effects of microplastic ingestion, especially long term effects, for organisms such as fish, it causes digestive tract changes, and it also causes increased stress in these organisms," says Hou.While the findings are stark -- McMahan described one of the paper's graphs showing the sharp rise in microplastics as "alarming" -- the researchers hope it will serve as a wake-up call. "The entire purpose of our work is to contribute to solutions," says Hoellein. "We have some evidence that public education and policies can change our relationship to plastic. It's not just bad news, there's an application that I think should give everyone a collective reason for hope."The researchers say the study also highlights the importance of natural history collections in museums. "Loren and I both love the Field Museum but don't always think about it in terms of its day-to-day scientific operations," says Hoellein. "It's an incredible resource of the natural world, not just as it exists now but as it existed in the past. It's fun for me to think of the museum collection sort of like the voice of those long dead organisms that are still telling us something about the state of the world today.""You can't do this kind of work without these collections," says McMahan. "We need older specimens, we need the recent ones, and we're going to need what we collect in the next 100 years."
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Zoology
| 2,021 |
April 12, 2021
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https://www.sciencedaily.com/releases/2021/04/210412101921.htm
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Prehistoric Pacific Coast diets had salmon limits
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Humans cannot live on protein alone -- even for the ancient indigenous people of the Pacific Northwest whose diet was once thought to be almost all salmon.
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In a new paper led by Washington State University anthropologist Shannon Tushingham, researchers document the many dietary solutions ancient Pacific Coast people in North America likely employed to avoid "salmon starvation," a toxic and potentially fatal condition brought on by eating too much lean protein."Salmon was a critical resource for thousands of years throughout the Pacific Rim, but there were a lot of foods that were important," said Tushingham the lead author of the paper published online on April 8 in the Some archeologists have contended for years that prehistoric Northwest people had an "extreme salmon specialization," a theory primarily based on the amount of salmon bone found at archeological sites.Tushingham and her co-authors argue that such a protein-intensive diet would be unsustainable. They point to nutritional studies and a global database of hunter-gatherer diets that indicate people have dietary limit on lean protein of around 35%. While it can vary by individual, exceeding that ceiling can be physically debilitating within a few days and fatal within weeks. Early explorers in the U.S. West subsisting on lean wild game discovered this problem the hard way and called it "rabbit starvation" or "caribou sickness."This toxic situation can apply to any lean meat, including salmon, Tushingham said. To avoid "salmon starvation," early Pacific Coast people had to find ways to get other nutrients, especially for children and nursing mothers who have even lower dietary thresholds for lean protein."There were ingenious nutritional and cultural solutions to the circumstances in the Northwest," said Tushingham. "Yes, salmon was important, but it wasn't that simple. It wasn't just a matter of going fishing and getting everything they needed. They also had to think about balancing their diet and making sure everybody could make it through the winter."The researchers point to evidence in California that people offset stored salmon protein with acorns; in Oregon and Washington, they ate root crops like camas as well as more fat-heavy fish such as eulachon. Further north, where plants are more limited, communities often ate marine mammals with high fat content such as seals and walrus. In far north interior, where there are few plants and the salmon runs can go thousands of miles inland, this was particularly challenging. Lean dried salmon was an important food source, and people circumvented salmon starvation through trading for oil with coastal peoples or obtaining fat through processing bone marrow from caribou and elk.The authors focus on the limits of salmon, which used to be considered a "prime mover" of Pacific Northwest populations, but their analysis also has implications for the study of historical human nutrition. If their argument is correct, it is unlikely that any human society was fully driven by pursuit of protein alone as their diets had to be more complex."People try to come up with one 'paleo-diet,' but there was no one specific ideal diet," said Tushingham. There were nutritional baselines that they had to cover, and nutritional limits that they couldn't exceed. There were many good solutions. It depended on where you lived and the history of your community."
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Zoology
| 2,021 |
April 8, 2021
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https://www.sciencedaily.com/releases/2021/04/210408152322.htm
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Can a 3D printed beetle model simulate the real thing?
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When it comes to choosing a partner, humans tend to be attracted by characteristics like personality and common interests. In contrast, insects tend to be a bit shallow, as they choose a mate based on appearance, and in some cases, smells. One example is the leaf beetle, which produces chemical pheromones that are on their cuticles, or the exterior surface of the beetle. They use these 'scents' to assess beetle sex and mating status (whether beetles are sexually mature or not).
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Kari Segraves, professor of biology in the College of Arts and Sciences, is interested in researching the chemical and visual signals that contribute to mate selection by these beetles. This work is part of a larger project focused on understanding how new species are formed. By definition, species are related organisms that share common characteristics and are capable of interbreeding. Mating studies are essential in determining the mechanisms that might lead to reproductive barriers between newly formed species.In the past, she and her colleagues have used a variety of models during these studies, including dead females and even round glass beads. To find a new and improved way of studying these insects, Segraves recently collaborated with Huai-Jun Xue and Si-Qin Ge from the Institute of Zoology, Chinese Academy of Sciences, to design, produce and test 3D printed beetle models to find out if they would be a feasible option when testing mate choice in these and possibly other insects. They believe this novel research to be the first time that 3D printed beetles have been used in mating tests.According to Segraves, they designed this study after receiving some unusual results in a mating experiment that focused on the chemical signals used by leaf beetles. In that study, they used dead beetles as mating models and swapped the chemical signals between the sexes so that the male model smelled like a female and the female model smelled like a male. Contrary to what they expected, they found that males did not have a preference for female over male chemical signals. This suggested that the trial itself may have been flawed because they had shown that the beetles always preferred females in another experiment that used chemically unaltered dead beetle models. They were concerned that more chemicals were being released after they had washed the dead models and that this was altering the results."We thought it would be a good idea to try using 3D printed models instead of dead females because the plastic used in 3D printing doesn't have chemicals that would be confused as mating signals by the beetles," Segraves says. She and fellow researchers from the Chinese Academy of Sciences conducted the planning and design of the work, and the 3D beetles were produced and tested in Huai-Jun Xue's lab in China."In the study, we learned that the 3D models worked and were more effective than models that weren't shaped like the beetles such as glass beads," Segraves notes. Another interesting result revealed that males use color in mate selection as males tested on black versus white 3D models all chose the black models.In the end, the researchers determined that when given an option, the beetles opt for the real thing over the 3D counterpart. When males were offered dead females with the reapplied chemical signals, males preferred dead females over black 3D models coated with the female scent. But Segraves says that's to be expected given that there are probably other types of signals that can't be replicated by 3D printing such as tactile signals.Their results indicate that in the absence of a dead female beetle, 3D-printed models can provide a feasible and cost-effective method for mating studies of insects. Segraves believes that going forward, researchers studying beetles and other similar insects should use a combination of models. While dead females are most realistic, the 3D printed models allows scientists to more tightly control the chemicals that are present in a given experiment.
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Zoology
| 2,021 |
April 8, 2021
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https://www.sciencedaily.com/releases/2021/04/210408131443.htm
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Fostered flamingos just as friendly
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Flamingo chicks raised by foster parents from another flamingo species develop normally, scientists say.
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Six Chilean flamingo chicks were reared by Andean flamingos -- a species of similar size and behaviour -- at WWT Slimbridge Wetland Centre in the summer of 2018.University of Exeter scientists studied the chicks' behaviour after they re-joined the Chilean flamingo flock early in 2019.The results showed fostering had no negative effects, with fostered flamingos still forming stable social ties -- making "friends" and behaving like parent-reared birds."Slimbridge's Andean flamingos hadn't nested for about 20 years," said Dr Paul Rose, of the University of Exeter."But in the hot summer of 2018 -- probably due to the high temperatures -- they made nests and laid eggs."Unfortunately, the eggs turned out to be infertile, possibly due to the age of the birds -- some of them are approaching their 60s."To give them enrichment (allowing them to behave naturally), keepers placed six eggs from the Chilean flamingo flock to be raised by the Andean flamingos."This gave us a rare opportunity to study the effects of fostering -- although it should be noted that these species are remarkably similar, and this would not have been attempted otherwise."Peter Kidd, then a student on Exeter's MSc Animal Behaviour course, observed and recorded the chicks' behaviour from April to July 2019 (after their return to their own flock).These observations were used to study integration and social networks."The six fostered chicks and seven parent-reared chicks quickly bonded back together," Kidd said."We found very slight behavioural differences -- small enough to be explained by individual variation -- and all chicks became embedded in the wider social network of the group."They all had favoured 'friends' to spend time with, which is normal flamingo behaviour."Species including the Andean flamingo rare in captivity (only two flocks worldwide) and are classified as "vulnerable" in the wild.Flamingos can be challenging to breed regularly in captivity, so the findings about successful fostering may help zoo conservation programmes."Foster rearing appears to be a safe method for conservation breeding of these species if done correctly," Dr Rose said."It is important to note that this fostering event went so smoothly because of the expert flamingo knowledge within the animal care teams at WWT."
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Zoology
| 2,021 |
April 8, 2021
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https://www.sciencedaily.com/releases/2021/04/210408112330.htm
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Weather radar for ecological forecasting can lessen hazards for migratory birds
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Forecasts aren't just for the weather. Scientists can use weather radar and related technology to chart the journeys of billions of migratory birds, which can help protect these global travelers from a growing array of threats.
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In a new breakthrough on this front, a team led by Colorado State University used millions of observations from 143 weather surveillance radars to evaluate a forecasting system for nocturnal bird migration in the United States.Using these tools, the team discovered that a mere 10 nights of action are required to reduce risk to 50% of avian migrants passing over a given area in spring and autumn. Specific actions are as simple as turning off nonessential outdoor lights.CSU's Kyle Horton, lead author of the study and an assistant professor in the Department of Fish, Wildlife and Conservation Biology, said that status quo tools for protecting migrating birds are somewhat inefficient. These migrating birds can be negatively impacted by light pollution, wind energy and collisions with structures."Even during peak migration, it's not efficient to tell people to turn off lights for a period of two to three weeks," Horton said. "Massive numbers of birds migrate on some nights, and at other times, not at all. As scientists, we want to be more mindful about how best to protect migrating birds."Wind turbines and nighttime lights serve specific purposes for energy production, commercial marketing or public safety. But researchers said with the tools to predict the most important nights when migrants take flight. It's easier to identify and encourage specific mitigation strategies.Horton teamed up on this research with scientists from University of Oxford, Cornell Lab of Ornithology, University of Wyoming, University of Massachusetts and Mount Holyoke College.Migration forecasts are available to the public through Horton's lab website and BirdCast, a collaborative project between the Cornell Lab of Ornithology, CSU and University of Massachusetts. BirdCast is supported by organizations including the National Science Foundation, NASA, the Leon Levy Foundation, Lyda Hill Philanthropies and Amon G. Carter Foundation.Benjamin Van Doren, a postdoctoral associate at the Cornell Lab of Ornithology and co-author on the study, said people can use BirdCast to see daily migration forecasts for the entire United States, as well as location-specific migration alerts."Everyone should use these tools to experience the spectacle of migration and guide actions for protecting birds," he said.BirdCast scientists, working with state and conservation officials, helped establish a Lights Out Texas initiative and pilot project in late 2020. Nearly one of every three birds migrating through the U.S. in spring pass through Texas, as do one of every four birds migrating through the U.S. in the fall -- totaling nearly 2 billion birds.Horton said that mayors in Dallas, Fort Worth and Houston have made commitments to support the new initiative. Former First Lady Laura Bush is also an outspoken advocate.In a recent op-ed in The Dallas Morning News, Bush encouraged Texans to turn off all nonessential lights from 11 p.m. to 6 a.m. during the state's peak spring bird migration, which occurs April 19 to May 7."Each night, each light turned out helps save migrating birds," she wrote. "And as an added bonus, turning off nonessential lights also saves energy for cities, local businesses and homeowners."Horton said the initiative in Texas will serve as a test bed for other cities across the country."The same principals equally apply in Denver, Fort Collins, Boulder, New York City or Los Angeles," he said. "These tools are the sort of the thing that agencies or cities and conservation managers can leverage to efficiently guide lights out programs."
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Zoology
| 2,021 |
March 31, 2021
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https://www.sciencedaily.com/releases/2021/03/210331114731.htm
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Revealing meat and fish fraud with a handheld 'MasSpec Pen' in seconds
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Meat and fish fraud are global problems, costing consumers billions of dollars every year. On top of that, mislabeling products can cause problems for people with allergies, religious or cultural restrictions. Current methods to detect this fraud, while accurate, are slower than inspectors would like. Now, researchers reporting in ACS'
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News stories of food fraud, such as beef being replaced with horse meat, and cheaper fish being branded as premium fillets, have led people to question if what is on the label is actually in the package. To combat food adulteration, the U.S. Department of Agriculture conducts regular, random inspections of these products. Although current molecular techniques, such as the polymerase chain reaction (PCR), are highly accurate, these analyses can take hours to days, and are often performed at off-site labs. Previous studies have devised more direct and on-site food analysis methods with mass spectrometry, using the amounts of molecular components to verify meat sources, but they also destroyed samples during the process or required sample preparation steps. More recently, Livia Eberlin and colleagues developed the MasSpec Pen -- a handheld device that gently extracts compounds from a material's surface within seconds and then analyzes them on a mass spectrometer. So, the team wanted to see whether this device could rapidly and effectively detect meat and fish fraud in pure filets and ground products.The researchers used the MasSpec Pen to examine the molecular composition of grain-fed and grass-fed beef, chicken, pork, lamb, venison and five common fish species collected from grocery stores. Once the device's tip was pressed against a sample, a 20-?L droplet of solvent was released, extracting sufficient amounts of molecules within three seconds for accurate analysis by mass spectrometry. The whole process took 15 seconds, required no preprocessing, and the liquid extraction did not harm the samples' surfaces. Then the team developed authentication models using the unique patterns of the molecules identified, including carnosine, anserine, succinic acid, xanthine and taurine, to distinguish pure meat types from each other, beef based on feeding habit and among the five fish species. Finally, the researchers applied their models to the analysis of test sets of meats and fish. For these samples, all models had a 100% accuracy identifying the protein source, which is as good as the current method of PCR and approximately 720 times faster. The researchers say they plan to expand the method to other meat products and integrate the MasSpec Pen into a portable mass spectrometer for on-site meat authentication.
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Zoology
| 2,021 |
March 31, 2021
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https://www.sciencedaily.com/releases/2021/03/210331085720.htm
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Tilapias are not precocious, they are just resilient
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Tilapias living in crowded aquaculture ponds or small freshwater reservoirs adapt so well to these stressful environments that they stop growing and reproduce at a smaller size than their stress-free counterparts.
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A new study by researchers at the University of Kelaniya in Sri Lanka and the University of British Columbia, explains that while most fishes die when stressed, tilapias survive in rough environments by stunting and carrying on with their lives in dwarf form."Tilapia and other fish in the Cichlidae family do not spawn 'earlier' than other fishes, as it is commonly believed," Upali S. Amarasinghe, lead author of the study and professor at the University of Kelaniya, said. "Rather, they are uncommonly tolerant of stressful environmental conditions which, however, elevate their oxygen demand."As it happens with other fishes, when tilapia's metabolism accelerates, it needs more oxygen to sustain its body functions. But the interaction between an increased metabolism and a growing body leads to gills reaching a point where they cannot supply enough oxygen for a larger body, so the fish either dies or just stops growing."Gill surface area grows in two dimensions, that is, length and width, but they cannot keep up with bodies that grow in three dimensions -- length, width and depth," said Daniel Pauly, co-author of the study and principal investigator of the In the case of tilapias, the stress they experience under suboptimal conditions adds to the stress they experience from the surface of their gills not keeping with the increasing oxygen demand of their growing bodies. In consequence, the hormonal cascade that leads to maturation and spawning is triggered at smaller sizes than under optimal conditions.But the spawning doesn't occur at a 'younger age,' as the fish's growth process has already ended.To reach this conclusion, the researchers analyzed the length at first maturity and maximum lengths reached in 41 populations of nine fish species such as tilapia and other cichlids found in lakes and aquaculture ponds across the world, from Brazil to Uganda, and from Egypt to Hong Kong.When looking at the ratio between the maximum lengths these fishes can reach and their lengths when they reproduce for the first time, they found it was the same ratio previously identified in other freshwater and marine fishes."This ratio tells us that tilapias in stressful conditions don't spawn 'earlier,' they just adjust their size downward, but their life cycle continues," Amarasinghe said."These findings will matter to fish farmers, notably in Asia, whose ponds are often full of wildly reproducing, small tilapia for which there is no market," Pauly said.
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Zoology
| 2,021 |
March 23, 2021
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https://www.sciencedaily.com/releases/2021/03/210323131208.htm
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A divided visual field
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Hummingbird hawkmoths are small insects that hover in the air like hummingbirds when drinking nectar from flowers. Dr. Anna Stöckl from the Biocentre of the Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany, is studying the visual performance of these insects. Dr. Stöckl and her doctoral student Ronja Bigge now present their latest findings in the journal
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"To control their flight, hummingbird hawkmoths rely on optic flow in the lower half of their visual field," Ronja Bigge explains. Optic flow is the relative motion that the surrounding image casts on the animals' retinas when they fly. We experience this phenomenon ourselves when travelling by train -- the landscape passing by the train windows allows us to estimate our speed, for example.For hawkmoths, the optic flow also provides information about their own movement. It helps them to control the straightness and speed of their flight. The JMU researchers have now shown with outdoor measurements that the optic flow components parallel to the direction of flight are always strongest below the hawkmoths' body. This is where the insects see meadows, gardens and streets that provide a varied texture. For flight control, what happens in the lower visual field is therefore the most reliable parameter."Surprisingly, we were able to show that the hawkmoths displayed a completely different and novel behaviour when we presented them with visual textures in the upper half of their visual field," says Anna Stöckl.The animals then oriented themselves along prominent contours in the patterns. Thus, they did not use the visual information for flight control, but for orientation -- although the visual patterns were exactly the same as the ones that were previously presented in the lower half of their visual field."Our optical measurements in natural habitats showed a comparable relationship: high-contrast structures that can be used for orientation occur primarily in the upper half of the visual field," says the JMU researcher. These are, for example, the silhouettes of treetops or bushes that form a strong contrast with the sky.The conclusion of the Würzburg biologists: "The flight control system and the orientation system of the hummingbird hawkmoth divide the visual field among themselves and focus on the respective area that provides the most reliable information in their natural habitats."In other words, it is not only important what the animals see, but also where they see it.
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Zoology
| 2,021 |
March 22, 2021
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https://www.sciencedaily.com/releases/2021/03/210322120117.htm
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Offshore pile driving noise alters feeding behaviors of longfin squid
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With the offshore wind industry expanding in the United States and elsewhere, a new study raises questions about how the noise from impact pile driving to install turbine supports can affect feeding behaviors of longfin squid, a commercially and ecologically important cephalopod.
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The research, conducted by scientists from the Woods Hole Oceanographic Institution (WHOI) and other institutions, is believed to be the first to demonstrate that anthropogenic noise prompts changes in cephalopod feeding behaviors."The whole reason we are doing this study is because we are concerned about how construction from offshore wind farms and the sounds associated with that are going to affect important fisheries species, one of them being this species of squid," said lead author Ian Jones about the paper published in this month's Longfin squid (Doryteuthis pealeii), whose habitat stretches among continental shelf waters from Newfoundland to the Gulf of Venezuela, are most abundant in waters off the Northeast U.S. coast, where offshore wind farms are planned for the 2020s and 2030s within 18 lease areas. Since 2010, longfin squid landings annually have amounted to about 11,000 metric tons and a value of $30 million, according to the U.S. National Marine Fisheries Service. Longfin squid also are important ecologically as a link between top predators and smaller fish and invertebrates.The study found that when squid in an experimental tank were exposed to audio recordings of pile driving, they were less likely to capture prey during the noise playback and are more likely to abandon pursuing prey, if the noise started during their hunt. Because the squid have a high metabolic rate and need to feed frequently, "[I]f cessation of feeding during noise leads to longer-term reduced food intake, then the potential exists for population-level reductions in squid abundance," according to the researchers.Pile driving involves repeated hammer strikes about every two seconds, to drive piles into the seabed and create support foundations for offshore development. The volume of underwater pile driving can exceed 200 decibels over a range of several hundred meters and the pitch of the noise can span frequencies from less than 100 Hz to over 10,000 Hz that can propagate for more than 10 kilometers.The study addressed short-term impacts to squid feeding behavior and noted that future research should look at longer exposures to noise and field work with free-swimming squid. In particular, the study found that rates of anti-predator behaviors were similar when subjected to recordings of piledriving whether the squid was hunting at the start of the noise, suggesting that the noise diverted squid attention from a feeding task toward predator defense.The study also found that the prey fish used in the experiment, killifish (Fundulus heteroclitus), could detect the sound of pile driving between 80 and 200 Hz.Jones said that historically research about the impact of noise on ocean organisms mostly has focused on marine mammals and, to some extent, on fish."There is such a huge knowledge gap for marine invertebrates in general, including squid," he said. "This study could help make a difference in closing that knowledge gap and in helping developers and the fishing industry be more aware of potential impacts of anthropogenic noise on longfin squid."
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Zoology
| 2,021 |
March 19, 2021
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https://www.sciencedaily.com/releases/2021/03/210319080817.htm
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Turns out altruism is for the fish
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If you were given the option to eat a delicious meal by yourself, or share that meal with your loved ones, you would need as very good excuse ready if you chose the former. Turns out, fish share a similar inclination to look after each other.
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For the first time ever, a research group led by researcher Shun Satoh and Masanori Kohda, professor of the Graduate School of Science, Osaka City University, have shown these altruistic tendencies in fish through a series of prosocial choice tasks (PCT) where they gave male convict cichlid fish two choices: the antisocial option of receiving food for themselves alone and the prosocial option of receiving food for themselves and their partner."As a result, it can be said that the convict cichlid fish properly distinguish between paired females, unknown females, and rival males, and change their choices according to the situation," states Dr. Satoh.However, what exactly happened?An experimental male fish was placed in a tank, and a fish was presented to the male fish in another tank. When a partner with whom the male fish had experience in raising children was in the presentation tank, the male fish actively made a prosocial choice and both fish received food. On the other hand, when there was no one in the presentation tank, the male fish preferred neither the prosocial nor antisocial option. To understand how the social context affected the fish's prosocial nature, the team changed the partners to rival males or females the experimental male fish had never met before. Results showed the male fish actively choose the antisocial option of not feeding the rival male, while choosing the prosocial option of feeding the unknown female as if it was their own breeding partner. In the latter experiment, the team also presented the original paired female near the experimental tank holding the male fish. In the absence of the paired female, the male fish made the prosocial choice which provided food for the unknown female, but in the presence of the paired female, they made the antisocial choice."These PCT results mirror those from similar experiments with primates," states Dr. Satoh. "However, this is the first time that caring and misbehaving behavior has been observed in fish. No one had ever expected such delicate and exquisite social behavior from such a small fish."Yet, there is still much work to do. "Through more rigorous behavioral experiments, we hope to clarify whether these fish really have psychosociality and the motivation to produce it and also how the mind of this type of fish evolved to produce it" states Prof. Kohda.There are hypotheses floating around as to the origin of this desire to care. Could it be a link that connects us past our primate ancestors, ultimately back to fish? Let us wait and see what else Prof. Kohda and his team find out.
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Zoology
| 2,021 |
March 19, 2021
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https://www.sciencedaily.com/releases/2021/03/210316112238.htm
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How do birds breathe better? Researchers' discovery will throw you for a loop
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Birds breathe with greater efficiency than humans due to the structure of their lungs -- looped airways that facilitate air flows that go in one direction -- a team of researchers has found through a series of lab experiments and simulations.
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The findings will appear Fri., March 19 in the journal The study, conducted by researchers at New York University and the New Jersey Institute of Technology, also points to smarter ways to pump fluids and control flows in applications such as respiratory ventilators."Unlike the air flows deep in the branches of our lungs, which oscillate back and forth as we breathe in and out, the flow moves in a single direction in bird lungs even as they inhale and exhale," explains Leif Ristroph, an associate professor at NYU's Courant Institute of Mathematical Sciences and the senior author of the paper. "This allows them to perform the most difficult and energetically costly activity of any animal: they can fly, and they can do so across whole oceans and entire continents and at elevations as high as Mount Everest, where the oxygen is extremely thin.""The key is that bird lungs are made of looped airways -- not just the branches and tree-like structure of our lungs -- and we found that this leads to one-way or directed flows around the loops," adds Ristroph. "This wind ventilates even the deep recesses of the lungs and brings in fresh air."The one-way flow of air in birds' breathing systems was discovered a century ago. But what had remained a mystery was an explanation of the aerodynamics behind this efficient breathing system.To explore this, the researchers conducted a series of experiments that mimicked birds' breathing in NYU's Applied Mathematics Lab.For the experiments, they built piping filled with water -- to replicate air flow -- and bent the piping to imitate the loop-like structure of birds' lungs -- similar to the way freeways are connected by on-ramps and off-ramps. The researchers mixed microparticles into the water, which allowed them to track the direction of the water flow.These experiments showed that back-and-forth motions generated by breathing were transformed into one-way flows around the loops."This is in essence what happens inside lungs, but now we could actually see and measure -- and thus understand -- what was going on," explains Ristroph, director of the Applied Mathematics Lab. "The way this plays out is that the network has loops and thus junctions, which are a bit like 'forks in the road' where the flows have a choice about which route to take."The scientists then used computer simulations to reproduce the experimental results and better understand the mechanisms."Inertia tends to cause the flows to keep going straight rather than turn down a side street, which gets obstructed by a vortex," explains NJIT assistant professor and co-author Anand Oza. "This ends up leading to one-way flows and circulation around loops because of how the junctions are hooked up in the network."Ristroph points to several potential engineering uses for these findings."Directing, controlling, and pumping fluids is a very common goal in many applications, from healthcare to chemical processing to the fuel, lubricant, and coolant systems in all sorts of machinery," he observes. "In all these cases, we need to pump fluids in specific directions for specific purposes, and now we've learned from birds an entirely new way to accomplish this that we hope can be used in our technologies."The paper's other authors were Steve Childress, a professor emeritus at the Courant Institute and co-director of the Applied Mathematics Lab; Quynh Nguyen, an NYU physics graduate student; Joanna Abouezzi and Guanhua Sun, NYU undergraduates at the time of the research; and Christina Frederick, an assistant professor at NJIT.The research was supported by the National Science Foundation (DMS-1720306, DMS-1646339, DMS-1847955) and the Simons Foundation.
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Zoology
| 2,021 |
March 18, 2021
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https://www.sciencedaily.com/releases/2021/03/210318101546.htm
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'By-the-wind sailor' jellies wash ashore in massive numbers after warmer winters
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As their name suggests, by-the-wind sailor jellies know how to catch a breeze. Using a stiff, translucent sail propped an inch above the surface of the ocean, these teacup-sized organisms skim along the water dangling a fringe of delicate purple tentacles just below the surface to capture zooplankton and larval fish as they travel.
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At the mercy of the wind, these jellies can wash ashore and strand -- sometimes numbering in the trillions -- on beaches around the world, including up and down the U.S. West Coast. And while these mass stranding events are hard to miss, very little actually is known about how or why they happen.Now, thanks to 20 years of observations from thousands of citizen scientists, University of Washington researchers have discovered distinct patterns in the mass strandings of by-the-wind sailors, also called Velella velella. Specifically, large strandings happened simultaneously from the northwest tip of Washington south to the Mendocino coast in California, and in years when winters were warmer than usual. The results were published March 18 in the journal "Citizen scientists have collected the largest and longest dataset on mass strandings of this jelly in the world," said senior author Julia Parrish, a professor in the UW School of Aquatic and Fishery Sciences and executive director of the Coastal Observation and Seabird Survey Team, known as COASST."This paper contributes to fundamental scientific knowledge of this organism in a way that traditional 'mainstream' marine science has been unable to do. Thousands of trained, dedicated observers are better than any satellite because they know their beach and can alert us if something is weird or unusual."COASST's citizen scientists are trained to search for and identify carcasses of marine birds that have washed ashore at sites from northern California to the Arctic Circle. Participants are asked to record and submit photos of anything strange or different they see on their stretch of beach.In 2019, program managers received an email from COASSTers in Oregon who had expected to see Velella on their beach based on past observations, but hadn't. That prompted COASST scientists to comb the database -- 23,265 surveys in total -- to see if others had taken note of these jellies over the years. This "data-mining" returned 465 reports of Velella littering 293 beaches, often in more than one year."On the water, Velella are beautiful, fragile creatures. When they wash ashore, these jellies quickly dry to the consistency of potato chips. During a mass stranding it's like walking on a crunchy carpet," Parrish said. "So of course, COASSTers reported in. Suddenly, we realized we had the largest dataset about Velella velella anywhere in the world."In analyzing the citizen science observations, UW researchers discovered that most by-the-wind sailors wash ashore on West Coast beaches during the spring, when the winds shift and push the organisms to shore. However, their analysis also revealed truly massive stranding events in 2003-2005 and again in 2015-2019. During the later years, jelly carcasses covered more than 620 miles (1,000 kilometers) of continuous coastline, all within a single two-week window between mid-March to mid-April.The second period corresponds with the timing of the long-lasting marine heat wave known as "the blob" -- also to blame for the largest seabird die-off of common murres, as well as mass die-offs of Cassin's auklets, sea lions and baleen whales.The researchers hypothesized that warmer winters during these years allowed for populations of by-the-wind sailors to spike in the open ocean. Then, when the winds shifted in the spring, massive numbers of the jellies were swept to shore and stranded.Put another way -- and though many ultimately end up dying on beaches -- the jellies appear to be "winners" during warmer periods, because they can amass more numbers in the ocean. There's some evidence that warmer-than-average winters are also calmer and less wavy in the open ocean, allowing increasingly large Velella aggregations to persist, Parrish explained."This paper and our data really do suggest that in a warming world, we're going to have more of these organisms -- that is, the ecosystem itself is tipping in the direction of these jellies because they win in warmer conditions," Parrish said. "A changing climate creates new winners and losers in every ecosystem. What's scary is that we're actually documenting that change."As warmer winters are expected to increase with climate change, these findings could have clear implications for this jelly population, as well as for the fish they eat and the beaches where they strand and die.
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Zoology
| 2,021 |
March 17, 2021
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https://www.sciencedaily.com/releases/2021/03/210317141651.htm
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Mitigating impact of artificial light at night in tropical forests
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Artificial light at night (ALAN) is a major factor in global insect decline. In a paper published today in
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"While many people aren't necessarily fond of 'bugs,' their importance in our everyday lives is indisputable," said Jessica Deichmann, first author and research scientist with the Smithsonian Conservation Biology Institute and the Smithsonian Conservation Commons' Working Land and Seascapes Initiative. "The essential ecosystem services they provide are endangered by nighttime lighting. We shouldn't abandon using LED lights -- their energy efficiency is second to none. Our research presents an alternative, especially for outdoor settings. If people everywhere take small steps in our homes, neighborhoods and commercial properties, we can reduce the negative impacts of sustainable LED lighting on wildlife."In addition to using filtered LEDs that remove the blue light and appear more orange/amber in color, additional ways to support insects include the use of full cutoff fixtures, motion activators and dimmers to ensure light is used only when and where it is needed.Insects play invaluable roles as pollinators of food plants, regulators of other insect pests, decomposers of waste and sources of food for other animals, like birds. Insects may be directly affected by lights when they suffer mortality from collisions with hot lamps, exhaustion or increased predation due to the attraction of predators and/or increased visibility. Insects affected by artificial lighting may also become disoriented or inactive, leading to a failure to reproduce, and consequently, a reduction of gene flow in the population.The study was conducted in lowland rainforest in northern Peru inside a hydrocarbon (oil and gas) concession currently operated by GeoPark Peru. Scientists set light traps in 12 different locations with three different LED lamps with different spectra and a control (no light) to evaluate the number and composition of insects attracted to lamps during two different time periods at night.Researchers identified 763 unique morphospecies among the greater than 15,000 insects captured across all samples, belonging to 18 different orders. Overall, significantly more morphospecies were captured in the white LED light traps than in either the yellow or amber-filtered traps or the control. Likewise, significantly more individual insects were captured in the white LED traps.By using amber-filtered LEDs, the number of morphospecies attracted to the light was reduced by 34% and individual insects were reduced by nearly 60% as compared to white LED lamps with reduced blue-light content. In addition, among captured insect families known to contain important vectors of pathogens, bacteria or parasites, 45% of all individuals were captured at white lamps, 41% at yellow lamps and just 13% were found in amber lamp traps.These results provide essential, tangible and actionable information on how to minimize ALAN, an unavoidable consequence of many types of infrastructure development and urbanization. The paper lays out specific management recommendations for new infrastructure projects in tropical forests that can also be applied to urban and rural residential areas.The paper's other co-authors are Christian Ampudia Gatty, Universidad Nacional de la Amazonía Peruana, Facultad de Ciencias Biológicas; Juan Manuel Andia Navarro, Universidad Nacional Agraria La Molina, Museo de Entomología Klaus Raven Büller; Alfonso Alonso, SCBI; Reynaldo Linares-Palomino, SCBI; and Travis Longcore, UCLA Institute of the Environment and Sustainability.
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Zoology
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316112303.htm
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Controlling sloshing motions in sea-based fish farming cages improves fish welfare
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Sea-based fish farming systems using net pens are hard on the environment and the fish. A closed cage can improve fish welfare, but fresh seawater must be continuously circulated through the cage. However, ocean waves can cause this circulating water to slosh inside the cage, creating violent motions and endangering the cage and the fish.
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A study using a scale-model fish containment system is reported in Gentle currents can be artificially maintained inside cylindrical closed cages developed for salmon farming. The current is produced by injecting seawater through nozzles in the side, creating a circular flow inside. The maximum flow rate should not exceed the critical swimming speed at which salmon can swim comfortably for an extended time.While this artificial current improves fish health, it also affects the natural frequencies of sloshing that can be excited inside the floating cage by ocean waves. These violent sloshing motions occur even when relatively small waves hit the cage, since the resonance phenomenon amplifies wave motion."In the scientific literature, similar problems of fluid dynamic behavior in spinning tanks have been found only in studies of stability and control of rocket fuel tanks, gas turbines, and centrifuges," co-author Claudio Lugni said."It is not straightforward to apply results about rocket tanks to aquaculture tanks," said co-author Andrei Tsarau.To address this problem, a scale model of a cylindrical fish cage was attached to a mechanical rig that could move the cylinder from side to side. The scale model was partially filled with water and included nozzles to inject an artificial circular current.When the system was oscillated sideways by the rig, sloshing motions began and were monitored by sensors in the tank."Depending on the forcing frequency, various sloshing regimes characterized by different wave shapes and amplitudes on the free surface of the liquid were observed in the experiment," Lugni said.Computational and theoretical studies with and without the rotating current were carried out and compared to the experiment. The investigators found the violent sloshing observed when the liquid in the cylinder is not circulated can be suppressed at the same excitation frequencies if the liquid is rotated at high enough angular velocities.This effect may be beneficial for relatively small cages with a radius less than 10 meters under forced-sloshing conditions. In such cages, the liquid can be rotated at high enough angular velocity without forcing the fish to swim at speeds above their critical limit."For larger cages, the same angular velocity would lead to flow velocities too high for the fish," said Tsarau.
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Zoology
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316083758.htm
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How hummingbirds hum
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The hummingbird is named after its pleasant humming sound when it hovers in front of flowers to feed. But only now has it become clear how the wing generates the hummingbird's namesake sound when it is beating rapidly at 40 beats per second. Researchers from Eindhoven University of Technology, Sorama, a TU/e spin-off company, and Stanford University meticulously observed hummingbirds using 12 high-speed cameras, 6 pressure plates and 2176 microphones. They discovered that the soft and complex feathered wings of hummingbirds generate sound in a fashion similar to how the simpler wings of insect do. The new insights could help make devices like fans and drones quieter.
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The team of engineers succeeded in measuring the precise origin of the sound generated by the flapping wings of a flying animal for the first time. The hummingbird's hum originates from the pressure difference between the topside and underside of the wings, which changes both in magnitude and orientation as the wings flap back and forth. These pressure differences over the wing are essential, because they furnish the net aerodynamic force that enables the hummingbird bird to liftoff and hover.Unlike other species of birds, a hummingbird wing generates a strong upward aerodynamic force during both the downward and upward wing stroke, so twice per wingbeat. Whereas both pressure differences due to the lift and drag force acting on the wing contribute, it turns out that the upward lifting pressure difference is the primary source of the hum.Professor David Lentink of Stanford University: "This is the reason why birds and insects make different sounds. Mosquitoes whine, bees buzz, hummingbirds hum, and larger birds 'woosh'. Most birds are relatively quiet because they generate most of the lift only once during the wingbeat at the downstroke. Hummingbirds and insects are noisier because they do so twice per wingbeat."The researchers combined all measurements in a 3D acoustic model of bird and insect wings. The model not only provides biological insight into how animals generate sound with their flapping wings, it also predicts how the aerodynamic performance of a flapping wing gives the wing sound its volume and timbre. "The distinctive sound of the hummingbird is perceived as pleasant because of the many 'overtones' created by the varying aerodynamic forces on the wing. A hummingbird wing is similar to a beautifully tuned instrument," Lentink explains with a smile.To arrive at their model, the scientists examined six Anna's hummingbirds, the most common species around Stanford. One by one, they had the birds drink sugar water from a fake flower in a special flight chamber. Around the chamber, not visible to the bird, cameras, microphones and pressure sensors were set up to precisely record each wingbeat while hovering in front of the flower.You can't just go out and buy the equipment needed for this from an electronics store. CEO and researcher Rick Scholte of Sorama, a spin-off of TU Eindhoven: "To make the sound visible and be able to examine it in detail, we used sophisticated sound cameras developed by my company. The optical cameras are connected to a network of 2176 microphones for this purpose. Together they work a bit like a thermal camera that allows you to show a thermal image. We make the sound visible in a 'heat map', which enables us to see the 3D sound field in detail."To interpret the 3D sound images, it is essential to know what motion the bird's wing is making at each sound measurement point. For that, Stanford's twelve high-speed cameras came into play, capturing the exact wing movement frame-by-frame.Lentink: "But that's not end of story. We also needed to measure the aerodynamic forces the hummingbird's wings generates in flight. We had to develop a new instrument for that." During a follow-up experiment six highly sensitive pressure plates finally managed to record the lift and drag forces generated by the wings as they moved up and down, a first.The terabytes of data then had to be synchronized. The researchers wanted to know exactly which wing position produced which sound and how this related to the pressure differences. Scholte: "Because light travels so much faster than sound, we had to calibrate each frame separately for both the cameras and the microphones, so that the sound recordings and the images would always correspond exactly." Because the cameras, microphones and sensors were all in different locations in the room, the researchers also had to correct for that.Once the wing location, the corresponding sound and the pressure differences are precisely aligned for each video frame, the researchers were confronted with the complexity of interpretating high volume data. The researchers tackled this challenge harnessing artificial intelligence, the research of TU/e PhD student, and co-first author, Patrick Wijnings.Wijnings: "We developed an algorithm for this that can interpret a 3D acoustic field from the measurements, and this enabled us to determine the most probable sound field of the hummingbird. The solution to this so-called inverse problem resembles what a police facial composite artist does: using a few clues to make the most reliable drawing of the suspect. In this way, you avoid the possibility that a small distortion in the measurements changes the outcome."The researchers finally managed to condense all these results in a simple 3D acoustic model, borrowed from the world of airplanes and mathematically adapted to flapping wings. It predicts the sound that flapping wings radiate, not only the hum of the hummingbird, but also the woosh of other birds and bats, the buzzing and whining of insects and even the noise that robots with flapping wings generate.Although it was not the focus of this study, the knowledge gained may also help improve aircraft and drone rotors as well as laptop and vacuum cleaner fans. The new insights and tools can help make engineered devices that generate complex forces like animals do quieter.This is exactly what Sorama aims to do: "We make sound visible in order to make appliances quieter. Noise pollution is becoming an ever-greater problem. And a decibel meter alone is not going to solve that. You need to know where the sound comes from and how it is produced, in order to be able to eliminate it. That's what our sound cameras are for. This hummingbird wing research gives us a completely new and very accurate model as a starting point, so we can do our work even better," concludes Scholte.This research appears on March 16 in the journal
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Zoology
| 2,021 |
March 16, 2021
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https://www.sciencedaily.com/releases/2021/03/210316093445.htm
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Migration routes of one of Britain's largest ducks revealed
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New research, just published in the journal
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Their findings reveal -- for the first time -- the length, speed and flight heights of this journey.Offshore wind farms are a key part of many governments' strategies to reduce carbon emissions and mitigate climate change impacts. However, it is important to understand how they might affect wildlife.The risk of colliding with wind turbines, is a particular concern to migratory species travelling across the sea, and there is also a potential increased energetic cost if wind farms act as a barrier that migrating birds must fly around.The majority of British and Irish Shelduck undergo a 'moult migration' to the Wadden Sea, which runs along the coasts of the Netherlands, Germany and Denmark. They make this journey every year in late summer, after they have finished breeding.Once there, they replace their old and worn out feathers and become flightless in the relative safety that the Wadden Sea offers, before returning to Britain when their moult is complete. However, in journeying to and from the Wadden Sea, Shelduck must cross the North Sea and navigate its growing number of wind farms en route.Scientists from the British Trust for Ornithology (BTO) used state of the art tags to track four Shelduck from the Alde-Ore Estuary Special Protection Area on the Suffolk coast to the Wadden Sea. Each bird took a separate route across the North Sea, and used previously unreported stopover sites in the Dutch Wadden Sea, before continuing on to moult sites in the Helgoland Bight off the coast of Germany. Incredibly, one bird travelled back and forth between the Dutch and German Wadden Seas four times, adding an extra 1,000 km to its migratory journey.The reasons why remain a mystery.Ros Green, Research Ecologist at BTO and lead author on the paper, said, "Having a working knowledge of species' migratory movements is an essential first step in understanding the risks that offshore wind farms may pose to populations of Shelduck and other species. Further, our tags provided data on Shelduck flight speeds and height, giving additional vital information on the magnitude of the risks posed by developments."She added, "It is well known that British and Irish Shelduck populations move back and forth across the North Sea each year, but this is the first published data on the specific routes taken, how long the migration takes to complete, and how fast and high Shelduck fly."The four Shelduck were fitted with solar powered GPS-GSM tags, allowing BTO scientists to follow their migratory movements in great detail and in almost real time, as the GPS data are downloaded over mobile phone networks.Incredibly, although all four birds took very different routes across the North Sea, they all ended their migration in almost exactly the same place in the Dutch Wadden Sea. During the crossing, the birds flew at speeds of up to 55 knots, and up to 354 m above the sea's surface.The movements recorded indicated apparent interactions with several wind farm sites, though most of these are currently only at the planning phase.Only one data fix was recorded within an operational wind farm when a bird flew within the Egmond aan Zee wind farm.This Shelduck was flying at a height of 85 m, which would place it at potential risk of collision with the wind farm's spinning turbine blades, which sweep an area between 25 and 139 m above sea level.Indeed, the majority of the four Shelducks' flight occurred below 150 m above sea level, which would place them in the 'collision risk zone' of many of the offshore wind farms they may pass through.The BTO team plans to extend the tracking project and collect more data to investigate whether Shelduck are actually at risk of collision, or whether the population can adapt to this essential renewable energy infrastructure."Further work," the research team add, "is also needed on tagging approaches in order to extend the deployment period beyond the main moult, and capture data on the return migration. A larger sample size of tracked birds is needed before firm conclusions on Shelduck migration can be drawn. Ideally this would include birds from a wider geographical range of British breeding sites, as well as Shelduck that breed on the continent but migrate to Britain for the winter."
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Zoology
| 2,021 |
March 9, 2021
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https://www.sciencedaily.com/releases/2021/03/210309192539.htm
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Both old and young fish sustain fisheries
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Scientists have used modern genetic techniques to prove age-old assumptions about what sizes of fish to leave in the sea to preserve the future of local fisheries.
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"We've known for decades that bigger fish produce exponentially more eggs," said the lead author of the new study, Charles Lavin, who is a research fellow from James Cook University (JCU) and Nord University in Norway."However, we also found while these big fish contributed significantly to keeping the population going -- they are also rare."Co-author Dr Hugo Harrison from the ARC Centre of Excellence for Coral Reef Studies at JCU said as fish grow older, they become more fertile and their chances of having babies increase."This is an age-old assumption of fisheries management -- and with the help of modern genetics, we can show that this assumption is correct.""But the smaller fish are just as important to keeping populations going. They may have fewer babies, but they also are more abundant."The study used genetic parentage analysis to identify which adult coral groupers (Plectropomus maculatus) contribute to replenishing fished populations in the Great Barrier Reef Marine Park (GBRMP).The authors found that large coral groupers are important because they are more likely to replenish the fish stocks removed from the fishery. However, smaller fish are still making a meaningful contribution."We show that minimum size-limits on catches are effective at protecting the reproductively mature coral grouper," Mr Lavin said. "This ensures all fish have the opportunity to reproduce at least once prior to being caught."The authors said all fisheries must ensure there are enough fish reproducing to replace the portion of the population that are caught."We're fortunate in the GBRMP to have measures in place that protect both the small and larger fish," Dr Harrison said."These ensure our fisheries remain sustainable and can bounce back quickly after a disturbance."In the GBRMP, catches of coral grouper are limited by size and catch limits, as well as seasonal closures to ensure the fishery is productive and sustainable."It's encouraging that these measures are effective," Mr Lavin said."But it's important that we also protect the bigger, rarer fish inside no-take marine reserves because they are super-productive," he said."For the fisher, this means there will always be fish to catch."
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Zoology
| 2,021 |
March 8, 2021
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https://www.sciencedaily.com/releases/2021/03/210308131709.htm
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Study finds two servings of fish per week can help prevent recurrent heart disease
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An analysis of several large studies involving participants from more than 60 countries, spearheaded by researchers from McMaster University, has found that eating oily fish regularly can help prevent cardiovascular disease (CVD) in high-risk individuals, such as those who already have heart disease or stroke.
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The critical ingredient is omega-3 fatty acids, which researchers found was associated with a lower risk of major CVD events such as heart attacks and strokes by about a sixth in high-risk people who ate two servings of fish rich in omega-3 each week."There is a significant protective benefit of fish consumption in people with cardiovascular disease," said lead co-author Andrew Mente, associate professor of research methods, evidence, and impact at McMaster and a principal investigator at the Population Health Research Institute.No benefit was observed with consumption of fish in those without heart disease or stroke."This study has important implications for guidelines on fish intake globally. It indicates that increasing fish consumption and particularly oily fish in vascular patients may produce a modest cardiovascular benefit."Mente said people at low risk for cardiovascular disease can still enjoy modest protection from CVD by eating fish rich in omega-3, but the health benefits were less pronounced than those high-risk individuals.The study was published in The findings were based on data from nearly 192,000 people in four studies, including about 52,000 with CVD, and is the only study conducted on all five continents. Previous studies focused mainly on North America, Europe, China and Japan, with little information from other regions."This is by far the most diverse study of fish intake and health outcomes in the world and the only one with sufficient numbers with representation from high, middle and low income countries from all inhabited continents of the world," said study co-lead Dr. Salim Yusuf, professor of medicine at the Michael G. DeGroote School of Medicine and executive director of the PHRI.This analysis is based in data from several studies conducted by the PHRI over the last 25 years. These studies were funded by the Canadian Institutes for Health Research, several different pharmaceutical companies, charities, the Population Health Research Institute and the Hamilton Health Sciences Research Institute.
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Zoology
| 2,021 |
March 4, 2021
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https://www.sciencedaily.com/releases/2021/03/210304145400.htm
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Did woolly mammoths overlap with first humans in what is now New England?
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Woolly mammoths may have walked the landscape at the same time as the earliest humans in what is now New England, according to a Dartmouth study published in
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"It has long been thought that megafauna and humans in New England did not overlap in time and space and that it was probably ultimately environmental change that led to the extinction of these animals in the region but our research provides some of the first evidence that they may have actually co-existed," explains co-author Nathaniel R. Kitchel, the Robert A. 1925 and Catherine L. McKennan Postdoctoral Fellow in anthropology at Dartmouth.The Mount Holly mammoth, Vermont's state terrestrial fossil, was discovered in the summer of 1848 in the Green Mountains during the construction of the Burlington and Rutland railroad lines. One molar, two tusks, and an unknown number of bones were excavated from a hilltop bog near Mount Holly. Over time, the specimens became scattered across several repositories, as they transferred from one collection to the next. A rib fragment from the Mount Holly mammoth became part of the Hood Museum of Art's collection and some of the other skeletal materials are now housed at the Museum of Comparative Zoology at Harvard University and the Mount Holly Historical Museum.Kitchel stumbled across the Mount Holly mammoth rib fragment last December at the Hood Museum's offsite storage facility, as curators had invited him to take a look at some of their artifacts from New Hampshire and Vermont. He came across a large bone (approximately 30 cm. in length) that was stained brown in color from age. He had a hunch that this was the remains of a mammoth and when he looked down at the tag, it read, "Rib of fossil elephant. Mt. Holly R.R. cut. Presented by Wm. A. Bacon Esq. Ludlow VT." This was rather serendipitous for Kitchel, as he had recently delivered a talk at Mount Holly's Historical Museum for which he had read up on the Mount Holly mammoth.To appreciate the significance of the Mount Holly mammoth remains, including the rib fragment, it is helpful to understand the paleontology of the Northeast. During the Last Glacial Maximum around 18,000 -- 19,000 years ago when glaciers were at their maximum extent, the ice began to retreat, gradually exposing what is now New England. During that period, it is likely that the glaciers probably sufficiently ripped up whatever soil might have been preserving fossils, reducing the likelihood for fossils to remain intact. These changes combined with the Northeast's naturally acidic soils have created inhospitable conditions for the preservation of fossils. While Kitchel had discussed the complicated paleontology of the Northeast in the past with colleague and co-author Jeremy DeSilva, an associate professor of anthropology at Dartmouth, he never thought that he would have much of an opportunity to work on it.After seeing this mammoth material in the Hood's collection, he and DeSilva decided to obtain a radiocarbon date of the fragmentary rib bone. They took a 3D scan of the material prior to taking a small (1 gram) sample from the broken end of the rib bone. The sample was then sent out to the Center for Applied Isotope Studies at the University of Georgia for radiocarbon dating and a stable istotopic analysis.Radiocarbon dating enables researchers to determine how long an organism has been dead based on its concentration of carbon-14, a radioactive isotope that decays over time. Stable isotopes however, are isotopes that do not decay over time, which provide a snapshot of what was absorbed into the animal's body when it was alive. Nitrogen isotopes can be used to analyze the protein composition of an animal's diet. The nitrogen isotopes of the Mount Holly mammoth revealed low values in comparison to that of other recorded mammoths globally while also reflecting the lowest value recorded in the Northeast for a mammoth. The low nitrogen values could have been the result of these mega-herbivores having to consume alder or lichens (nitrogen fixing species) during the last glacial period when the landscape was denser due to climate warming."The Mount Holly mammoth was one of the last known occurring mammoths in the Northeast," says DeSilva. "While our findings show that there was a temporal overlap between mammoths and humans, this doesn't necessarily mean that people saw these animals or had anything to do with their death but it raises the possibility now that maybe they did."The radiocarbon date for the Mount Holly mammoth of 12,800 years old overlaps with the accepted age of when humans may have initially settled in the region, which is thought to have occurred during the start of the Younger Dryas, a final pulse of glacial cold before temperatures warmed dramatically, marking the end of the Pleistocene (Ice Age).While other research on mammoths in the Midwest suggests that humans hunted and buried these animals in lakes and bogs to preserve the meat, there's little evidence that early humans in New England hunted or scavenged these animals.The researchers are intrigued by the Mount Holly mammoth. The rest of its rib and other bones could be waiting to be discovered. Or, through time, they could have broken apart, dissolved in the acidic soil, or a scavenger could have run off with the bones. There are still a lot of unknowns; yet, the team has already begun further research using modern and more sophisticated archaeological techniques to explore what may be underground at Mount Holly.
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Zoology
| 2,021 |
March 2, 2021
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https://www.sciencedaily.com/releases/2021/03/210302104810.htm
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A robot able to 'hear' through the ear of a locust
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Researchers at Tel Aviv University report that they have successfully connected the ear of a dead locust to a robot that receives the ear's electrical signals and responds accordingly. The result is extraordinary: When the researchers clap once, the locust's ear hears the sound and the robot moves forward; when the researchers clap twice, the robot moves backwards.
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The interdisciplinary study was led by Idan Fishel, a joint master student under the joint supervision of Dr. Ben M. Maoz of the Iby and Aladar Fleischman Faculty of Engineering and the Sagol School of Neuroscience, Prof. Yossi Yovel and Prof. Amir Ayali, experts from the School of Zoology and the Sagol School of Neuroscience together with Dr. Anton Sheinin, Idan, Yoni Amit, and Neta Shavil. The results of the study were published in the journal The researchers explain that at the beginning of the study, they sought to examine how the advantages of biological systems could be integrated into technological systems, and how the senses of dead locust could be used as sensors for a robot. "We chose the sense of hearing, because it can be easily compared to existing technologies, in contrast to the sense of smell, for example, where the challenge is much greater," says Dr. Maoz. "Our task was to replace the robot's electronic microphone with a dead insect's ear, use the ear's ability to detect the electrical signals from the environment, in this case vibrations in the air, and, using a special chip, convert the insect input to that of the robot."To carry out this unique and unconventional task, the interdisciplinary team (Maoz, Yovel and Ayali) faced number of challenged. In the first stage the researchers built a robot capable of responding to signals it receives from the environment. Then, in a multidisciplinary collaboration, the researchers were able to isolate and characterize the dead locust ear and keep it alive, that is, functional, long enough to successfully connect it to the robot. In the final stage, the researchers succeeded in finding a way to pick up the signals received by the locust's ear in a way that could be used by the robot. At the end of the process, the robot was able to "hear" the sounds and respond accordingly."Prof. Ayali's laboratory has extensive experience working with locusts, and they have developed the skills to isolate and characterize the ear," explains Dr. Maoz. "Prof. Yovel's laboratory built the robot and developed code that enables the robot to respond to electrical auditory signals. And my laboratory has developed a special device -- Ear-on-a-Chip -- that allows the ear to be kept alive throughout the experiment by supplying oxygen and food to the organ, while allowing the electrical signals to be taken out of the locust's ear and amplified and transmitted to the robot."In general, biological systems have a huge advantage over technological systems -- both in terms of sensitivity and in terms of energy consumption. This initiative of Tel Aviv University researchers opens the door to sensory integrations between robots and insects -- and may make much more cumbersome and expensive developments in the field of robotics redundant."It should be understood that biological systems expend negligible energy compared to electronic systems. They are miniature, and therefore also extremely economical and efficient. For the sake of comparison, a laptop consumes about 100 watts per hour, while the human brain consumes about 20 watts a day. Nature is much more advanced than we are, so we should use it. The principle we have demonstrated can be used and applied to other senses, such as smell, sight and touch. For example, some animals have amazing abilities to detect explosives or drugs; the creation of a robot with a biological nose could help us preserve human life and identify criminals in a way that is not possible today. Some animals know how to detect diseases. Others can sense earthquakes. The sky is the limit."
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Zoology
| 2,021 |
March 1, 2021
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https://www.sciencedaily.com/releases/2021/03/210301133447.htm
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Lake turbidity mitigates impact of warming on walleyes in upper Midwest lakes
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Because walleyes are a cool-water fish species with a limited temperature tolerance, biologists expected them to act like the proverbial "canary in a coal mine" that would begin to suffer and signal when lakes influenced by climate change start to warm. But in a new study, a team of researchers discovered that it is not that simple.
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"After analyzing walleye early-life growth rates in many lakes in the upper Midwest over the last three decades, we determined that water clarity affects how growth rates of walleyes change as lakes start to warm," said Tyler Wagner, Penn State adjunct professor of fisheries ecology. "In some lakes, warming actually led to increased walleye growth rates, in others there essentially was no change, and in others, growth rates declined. The different responses of growth rates to increasing water temperatures across lakes appear to be influenced by water turbidity."The research is significant, Wagner explained, because walleye fisheries in the upper Midwest are important not just ecologically, but also from an economic and cultural perspective. Because walleye fishing is a valued social activity in Minnesota and Wisconsin and hundreds of thousands of walleye fingerlings are stocked there to bolster wild populations, the region is the ideal place to study the effect of warming conditions on the fish.According to the U.S. Environmental Protection Agency, the Midwest has gotten warmer, with average annual temperatures increasing over the last several decades. Between 1900 and 2010, the average air temperature increased by more than 1.5 degrees Fahrenheit in the region."The rate of increase in air temperature has accelerated in recent decades, and this increase in air temperature will affect the thermal habitat for fishes across the region," Wagner said. "Temperatures are projected to continue increasing across the Midwest -- with the greatest increases in average temperature expected in northern areas -- so we wanted to know what was happening with walleye populations in the upper Midwest."Using data provided by the Minnesota and Wisconsin departments of Natural Resources, researchers quantified annual walleye early-life growth rates from 1983 to 2015 in 61 lakes in the upper Midwest. Then they estimated the relationship between early-life growth rates and water growing degree days -- an indicator of the temperature the fish are exposed to -- over those 32 years. Importantly, they also examined how water turbidity influenced growth rates across the 61 lakes, correlated to an increased number of growing degree days.Their findings, published Feb. 23 in the "Rather, lake-specific characteristics likely will be important in determining how walleye populations respond to climate change," he said.The analysis also indicated that walleye growth rates varied among lakes of different sizes, explained lead researcher Danielle Massie, who graduated from Penn State in 2020 with a master's degree in wildlife and fisheries science."Walleye early-life growth rates, on average, were significantly greater in larger lakes," she said. "Our results provide insights into the conservation of cool-water species in a changing environment and identify lake characteristics in which walleye growth may be at least somewhat resilient to climate change."The results of the research were surprising, Wagner conceded, because researchers expected to see walleye growth rates in most lakes decrease with more growing degree days -- since walleyes prefer cool water. But that did not happen in most of the lakes they studied."It sounds counterintuitive at first, but if we think about fish growth, we can think about it as a performance curve, where growth increases with increasing temperature to a certain point," he said. "But as the lake warms past that optimum temperature, the curve descends, and we'll see declining growth as the temperature increases beyond that point."Slightly higher water temperatures in some upper Midwest lakes have resulted in increased growth rates for walleyes, but if water temperatures continue to rise, influenced by a warming climate, walleye populations in the region will suffer, predicted Wagner, assistant leader of Penn State's Pennsylvania Cooperative Fish and Wildlife Research Unit, housed in the College of Agricultural Sciences."We're going to reach a water temperature tipping point where growth will decline, and then we'll see deleterious effects," he said. "This is why understanding what factors, such as turbidity and lake size, influence how fish populations respond to warming is critical for informing management and conservation efforts."
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Zoology
| 2,021 |
February 23, 2021
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https://www.sciencedaily.com/releases/2021/02/210223192451.htm
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Fighting fit cockroaches have 'hidden strength'
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A new study has discovered that not all cockroaches are equal and "super athletes," with larger respiratory systems, are more likely to win physical mating battles.
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The research, published in the journal Animal contests are usually won by the larger opponent and physical fighting is often avoided if clear differences exist between competitors. However, during a series of laboratory contests, the researchers closely matched the cockroaches for size so there were no visible differences in their fighting capabilities, known as their resource holding potential.Heavily weaponised male wide-horned hissing cockroaches use their pronotal horns as they compete for females through vigorous contests, often butting and flipping their male opponents onto their backs.Encounters also involve 'low aggression' behaviour including repeated approaches towards the opponent, which may retreat or adopt a low posture to guard against being overturned. During the laboratory contests, actions reflecting these dominant and submissive behaviours were scored for each animal.A CT scan of each cockroach was then carried out allowing the researchers to study their whole body, including the size of their respiratory system.Crucially, they found significant differences in the respiratory volumes of the cockroaches, and these were directly associated with their fighting prowess. The dominant individuals were found to have larger respiratory volumes compared to their similarly sized submissive opponents.Dr Sophie Mowles, Senior Lecturer in Animal and Environmental Biology at Anglia Ruskin University (ARU), said: "When studying contest behaviour it is important to consider not just the physical weaponry used by species, or the combative behaviours they employ, but also the underlying physiology that allows this energetically costly behaviour to take place."When visible differences are removed by size-matching opponents, fights between male cockroaches are likely to escalate into trials of strength, and our study found that some cockroaches have much larger respiratory capacities than others, allowing them to dominate these contests. The increased ability to effectively deliver oxygen to their body tissue may enhance the fighting ability of these dominant males."Adaptations for prolonging aerobic respiration in these cockroaches have probably evolved as a way of maximising oxygen exchange when burrowing through leaf litter, and we have shown that these adaptations also play a crucial role in physical contests between males, and therefore sexual selection."Video:
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Zoology
| 2,021 |
February 22, 2021
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https://www.sciencedaily.com/releases/2021/02/210222095042.htm
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Dogs synchronize their behavior with children, but not as much as with adults, study finds
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Dogs synchronize their behavior with the children in their family, but not as much as they do with adults, a new study from Oregon State University researchers found.
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The findings are important because there is a growing body of evidence that dogs can help children in many ways, including with social development, increasing physical activity, managing anxiety or as a source of attachment in the face of changing family structures, the researchers said. Yet, very little research has focused on how dogs perceive and socially engage with children."The great news is that this study suggests dogs are paying a lot of attention to the kids that they live with," said Oregon State animal behaviorist Monique Udell, the lead author of the study. "They are responsive to them and, in many cases, behaving in synchrony with them, indicators of positive affiliation and a foundation for building strong bonds."One interesting thing we have observed is that dogs are matching their child's behavior less frequently than what we have seen between dogs and adult caretakers, which suggests that while they may view children as social companions, there are also some differences that we need to understand better."The paper was recently published in the journal The researchers recruited 30 youth between the ages of 8 and 17 years old -- 83% of which had a developmental disability -- to take part in the study with their family dog. The experiments took place in a large empty room. Color-coded taped lines were placed on the floor, and the children were given instructions on how to walk the lines in a standardized way with their off-leash dog.The researchers videotaped the experiments and analyzed behavior based on three things: (1) activity synchrony, which means how much time the dog and child were moving or stationary at the same time; (2) proximity, or how much time the dog and child were within 1 meter of each other; and (3) orientation, how much time the dog was oriented in the same direction as the child.They found that dogs exhibited behavioral synchronization with the children at a higher rate than would be expected by chance for all three variables. During their assessments, they found:While child-dog synchrony occurred more often that what would be expected by chance, those percentages are all lower than what other researchers have found when studying interactions between dogs and adults in their household. Those studies found "active synchrony" 81.8% of the time, but at 49.1% with shelter dogs. They found "proximity" 72.9% of the time and 39.7% with shelter dogs. No studies on dog-human behavioral synchronization have previously assessed body orientation.The Oregon State researchers are conducting more research to better understand factors that contribute to differences in levels of synchrony and other aspects of bond quality between dogs and children compared to dogs and adults, including participation in animal assisted interventions and increasing the child's responsibility for the dog's care.While research has found dogs can have a lot of positive impacts on a child's life, there are also risks associated with the dog-child relationship, the researchers said. For example, other studies have found dogs are more apt to bite children versus adults."We still have a lot to learn about the dog-child relationship" Udell said. "We're hoping this research can inform the best ways to shape positive outcomes and mitigate risks by helping children interact with dogs in a manner that improves the relationship and ultimately the welfare of both individuals."Based on this study, Udell also offered some takeaways for families with children and dogs."What we are finding is that kids are very capable of training dogs, and that dogs are paying attention to the kids and can learn from them," she said. "Sometimes we don't give children and dogs enough credit. Our research suggests that with some guidance we can provide important and positive learning experiences for our kids and our dogs starting at a much earlier age, something that can make a world of difference to the lives of both."
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Zoology
| 2,021 |
February 18, 2021
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https://www.sciencedaily.com/releases/2021/02/210218180201.htm
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Songbirds' reproductive success reduced by natural gas compressor noise
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Some songbirds are not dissuaded by constant, loud noise emitted by natural gas pipeline compressors and will establish nests nearby. The number of eggs they lay is unaffected by the din, but their reproductive success ultimately is diminished.
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That's the conclusion of a team of Penn State researchers who conducted an innovative, elaborate study that included unceasing playback of recorded compressor noise, 80 new, never-before-used nest boxes occupied by Eastern bluebirds and tree swallows, and behavioral observations with video cameras placed within boxes.Importantly, the birds did not preferentially select quiet boxes over noisy boxes, suggesting they do not recognize the reduction in habitat quality resulting from the noise," said study co-author Margaret Brittingham, professor of wildlife resources, College of Agricultural Sciences. "But both bluebirds and tree swallows nesting in noisy boxes spent less time incubating their eggs, had fewer eggs hatch and produced fewer young than their neighbors nesting in quiet boxes."Natural gas is one of the most rapidly growing global energy sources, with continued expansion expected in shale gas development in particular. Compressor stations needed to pressurize gas and push it through pipelines to consumers -- often located in interior forests used by breeding birds -- may be depressing birds' reproduction in isolated forested areas."The loud, low-frequency noise emitted by natural gas compressor stations travels hundreds of yards into undisturbed areas," said co-author Julian Avery, associate research professor of wildlife ecology and conservation. "Because shale gas development often occurs in relatively undisturbed natural areas that provide important habitat for breeding birds, it is imperative that we develop plans to manage and mitigate noise."The experiment, believed to be the first of its kind, was conducted at Penn State's Russell E. Larson Agricultural Research Center at Rock Springs, in central Pennsylvania. The study was unique because the researchers took extensive precautions to be sure they were assessing only the birds' reaction to the compressor noise and not other factors.The design of the experiment allowed researchers to control for the confounding effects of both physical changes to the environment associated with compressor stations as well as the strong tendency for birds to return to the specific locations where they previously had bred.Researchers established the 40 pairs of nest boxes to attract bluebirds and tree swallows to a site with no previous breeding population and immediately introduced shale gas compressor noise to half the boxes before birds returned to the region, while the other 40 boxes served as controls."We took a risk initiating the study -- we weren't sure these birds would find and occupy our boxes," Avery said. "We hoped that, 'if we build it, they will come.' Bluebirds likely had other nearby spots to nest, and the tree swallows were just returning from Central America. There was no guarantee they'd encounter our boxes."The research was led by Danielle Williams, a master's degree student in wildlife and fisheries science, who currently is field coordinator for Purdue University's Hardwood Ecosystem Experiment.Williams monitored video feeds from cameras placed within boxes to document changes in breeding behavior. She noted that there was no difference in clutch size -- eggs laid -- between noisy boxes and quiet boxes. Feeding behavior by the adults, known as provisioning, also was the same in both. However, in both species, she observed a reduction in incubation time, hatching success and fledging success -- the proportion of all eggs that fledged -- in noisy boxes compared to quiet boxes.The findings, recently published in Nest success -- the probability of fledging at least one young -- calculated from all nests that were initiated, was not affected by noise in either species studied, Brittingham pointed out."That suggests that noise did not increase rates of either depredation or abandonment but instead negatively impacted fitness through reduced hatching and fledging success," she said. "We never would have known that if we had not done this research."Also involved in the research was acoustics expert Thomas Gabrielson, senior scientist, Penn State Applied Research Laboratory.The U.S. Department of Agriculture's National Institute of Food and Agriculture, Penn State's Schreyer Institute for Teaching Excellence, the Association of Field Ornithologists and the NASA Pennsylvania Space Grant Consortium funded this research.
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Zoology
| 2,021 |
February 12, 2021
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https://www.sciencedaily.com/releases/2021/02/210212111917.htm
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Birds can 'read' the Earth's magnetic signature well enough to get back on course
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Birdwatchers get very excited when a 'rare' migratory bird makes landfall having been blown off-course and flown beyond its normal range. But these are rare for a reason; most birds that have made the journey before are able to correct for large displacements and find their final destination.
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Now, new research by an international team shows for the first time, how birds displaced in this way are able to navigate back to their migratory route and gives us an insight into how they accomplish this feat.Writing in Different parts of the Earth have a distinct 'geomagnetic signature' according to their location. This is a combination of the strength of the geomagnetic field, the magnetic inclination or the dip angle between magnetic field lines and the horizon and the magnetic declination, or the angle between directions to the geographic and magnetic North poles.Adult birds already familiar with their migration route, and its general magnetic signatures, were held in captivity for a short period before being released back into the wild, and exposed to a simulation of the earth's magnetic signature at a location thousands of miles beyond the birds' natural migratory corridor.Despite remaining physically located at their capture site and experiencing all other sensory clues about their location, including starlight and the sights, smell and sounds of their actual location, the birds still showed the urge to begin their journey as though they were in the location suggested by the magnetic signal they were experiencing.They oriented themselves to fly in a direction which would lead them 'back' to their migratory path from the location suggested to them by the magnetic signals they were experiencing.This shows that the earth's magnetic field is the key factor in guiding reed warblers when they are blown off course."The overriding impulse was to respond to the magnetic information they were receiving," explained Richard Holland of Bangor University's School of Natural Sciences.What our current work shows is that birds are able to sense that they are beyond the bounds of the magnetic fields that are familiar to them from their year-round movements, and are able to extrapolate their position sufficiently from the signals. This fascinating ability enables bird to navigate towards their normal migration route."Dr Dmitry Kishkinev of Keele University's School of Life Sciences explained:"What these birds are achieving is "true navigation." In other words, they are able to return to a known goal after displacement to a completely unknown location without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey."Florian Packmor of Bangor University added: "We have already shown that the reed warblers use the same magnetic cues experienced within their natural range, but this study shows that they can extrapolate what they understand about how the magnetic field varies in space far beyond any previous experience they have had."But questions remain about whether the birds have an accurate 'map' or are just using a 'rule of thumb' measurement to judge the general direction of travel needed to get back on course.The Eurasian reed warbler was selected for the research, but the findings could probably be applied to other migrating songbirds.
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Zoology
| 2,021 |
February 11, 2021
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https://www.sciencedaily.com/releases/2021/02/210211090112.htm
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Family ties explain mysterious social life of coral gobies
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The strange social structure of tiny fish called emerald coral gobies may be explained by family loyalty, new research shows.
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Coral goby groups contain a single breeding male and female and -- as "sequential hermaphrodites" -- the subordinate gobies can take over either role if one of the breeders dies.The puzzle for biologists is why breeders tolerate the smaller non-breeders sharing their space and competing for food.One explanation is "kin selection" (favouring related individuals).Reef fish are often assumed to disperse at random after hatching, meaning groups of adults should not be closely related, but the new study finds "positive relatedness" among gobies living close together."Groups of emerald coral gobies have a fixed structure in which the breeders are biggest," said lead author Dr Theresa Rueger, of the University of Exeter and Boston University."The rest are not sexually mature, and they are even known to refrain from eating to avoid threatening the rank above them in the social order."They can't risk being evicted from the group, as this usually means being eaten by predators on the reef."Dr Rueger added: "Kin selection is commonly seen in birds and mammals, and our study demonstrates the potential for weak kin selection among coral gobies."In essence, it makes evolutionary sense to favour a distant cousin over an unrelated individual."The researchers examined the genes of 73 gobies from 16 groups in Kimbe Bay, Papua New Guinea, and estimated relatedness among all individuals.They found that gobies were significantly more related to members of their group than to gobies on the wider reef, and gobies in each reef were significantly more related to each other than to those from different reefs.Like many reef fish, gobies spend their early life in the open ocean -- where predators are larger and may not hunt tiny prey -- before returning to a reef.It might be assumed that the movement of larvae is dictated by ocean currents, but recent research has shown they have some ability to select currents and may therefore be able to return to the reef they came from -- explaining relatedness among fish on a reef.Previous research has explained why non-breeders tolerate their situation; gobies join groups for safety, and must then work their way up the social structure or risk eviction and death.The new study finally offers an explanation for why breeders tolerate non-breeders that share their resources.The research team included Cornell University and the University of Wollongong.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 841263.
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Zoology
| 2,021 |
February 9, 2021
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https://www.sciencedaily.com/releases/2021/02/210209113925.htm
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Bats and pangolins in Southeast Asia harbour SARS-CoV-2-related coronaviruses, reveals new study
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While the World Health Organization (WHO) continues its mission to Wuhan investigating the origin and early transmission of SARS-CoV-2, a new study led by scientists from Duke-NUS Medical School, Singapore, and Chulalongkorn University, Thailand, shows that SARS-CoV-2-related coronaviruses (SC2r-CoVs) are circulating in animals as far away as Thailand. The study, published in
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"This is an important discovery in the search for the origin of SARS-CoV-2, which was made possible by rapid application of cutting-edge technology through transparent international collaboration," said Dr Supaporn Wacharapluesadee, from Thai Red Cross Emerging Infectious Diseases Health Science Centre, Faculty of Medicine, Chulalongkorn University, Bangkok Thailand.In the study, the team examined Rhinolophus bats in a Thai cave. SARS-CoV-2 neutralising antibodies were detected in bats of the same colony and in a pangolin at a wildlife checkpoint in Southern Thailand."Our study extended the geographic distribution of genetically diverse SARS-CoV-2-related coronaviruses from Japan and China to Thailand over a 4,800-km range. Cross-border surveillance is urgently needed to find the immediate progenitor virus of SARS-CoV-2," said Dr Chee Wah Tan, Senior Research Fellow with Duke-NUS' Emerging Infectious Diseases (EID) programme and co-author of this study.The team conducted serological investigations using the SARS-CoV-2 surrogate virus neutralisation test (sVNT) developed at Duke-NUS in early 2020."Our study demonstrates that our SARS-CoV-2 surrogate virus neutralisation test, developed mainly for determining neutralising antibodies in humans to monitor vaccine efficacy and detect past infections, can also be critical for tracing the animal origin and animal-human spillover events," said Professor Wang Linfa from Duke-NUS' EID programme and corresponding author of this study.Prof Wang's team invented the sVNT assay, trade named cPass, which has been granted Emergency Use Authorisation by the US FDA to determine SARS-CoV-2-neutralising antibodies in human sera, due to its good performance concordance with live virus-based assays."Studies like this are crucial in furthering our understanding of the many SARS-CoV-2-related viruses that exist in the wild. This work is also timely as investigations into the origins of SARS-CoV-2 are ongoing and may provide further leads on the origin of this outbreak. Such studies also play a key role in helping us be better prepared against future pandemics as they provide a more detailed map of zoonotic threats, " said Prof Patrick Casey, Senior Vice Dean for Research at Duke-NUS.
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Zoology
| 2,021 |
February 8, 2021
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https://www.sciencedaily.com/releases/2021/02/210208100542.htm
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Captive-bred juvenile salmon unlikely to become migratory when released into streams
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Researchers at the Kobe University Graduate School of Science have revealed that when captive-bred juvenile red-spotted masu salmon are released into natural streams, very few individuals become migrants.
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Red-spotted masu salmon was an important fish species for the fishing industry in the rivers of west Japan, however in recent years their numbers are declining rapidly. The results of this research offer important suggestions for stocking practices and the management of river environments.The research group consisted of graduate school students TANAKA Tatsuya and UEDA Rui and Associate Professor SATO Takuya. The results were published in Preserving variation within a species is vital for many reasons, including for the species' long-term existence and for the sustainability of resources for humans. Migratory behavior is one example of variation in the life cycle of a particular species which is important for its continuation.For example, within most species of salmonid fish, there are two phenotypes: migratory and non-migratory (resident). Migratory fish travel from the rivers to the ocean and then return to the rivers to spawn, whereas non-migratory individuals live in rivers for their entire lives. However in recent years, various factors such as reduced connectivity between rivers and oceans have caused a sharp decline in the number of migratory individuals. Consequently, large numbers of salmonid fish that were bred in captivity are released into rivers across the globe with the aim of replenishing and conserving fishery resources.It is known that these stocking practices can contribute towards an increase in migratory individuals if the released captive-bred fish have already reached the preparatory stage for migration to the sea (smolt). However, in some stocking practices, juvenile fish that have yet to undergo smoltification are released. It is not known what percentage of these juveniles become migratory in natural rivers.In the However, the distribution of these salmon populations is sharply declining nationwide in recent years, due in part to rivers being cut off from the ocean by dams and other artificial barriers. As part of efforts to restore the numbers of migratory individuals in the wild, red-spotted masu salmon are raised in hatcheries and those with a high probability of becoming migratory are released into rivers.Red-spotted masu salmon that exceed the threshold size upon their first fall undergo smoltification and then become migratory individuals. On the other hand, those who do not grow large enough become residents and spend their entire lives in river waters.It has been reported that captive-bred fish experience delayed growth when they are released into rivers, due to factors such as being unable to obtain sufficient food Based on this information, the researchers predicted that, even in the case of captive-bred individuals that were highly likely to reach smoltification, juvenile fish released into natural rivers prior to smoltification would experience growth delays rendering them unable to exceed the threshold size required.In order to investigate this hypothesis, red-spotted masu salmon from two different hatcheries were released into the natural streams in the upper regions of the Arida River in Wakayama Prefecture, Japan (in 10 sections across 7 streams). The individuals had a high probability of reaching the smolt stage and were released in early summer prior to smoltification. In fall, the researchers investigated the size of the released fish and the percentage that became smolts. In an additional experiment, released fish were raised in outdoor tanks (in which they could access a similar availability of food resources to the hatchery) and the researchers investigated the percentage of smolt and threshold size required for smoltification in these groups.The results of this stocking experiment revealed that, out of 320 fish recaptured from natural streams, only one individual (0.3%) reached the smolt stage. In contrast, the numbers that achieved smoltification were much higher among the group that were raised in outdoor tanks, with 64% of females and 17% of males from K- hatchery, and 75% of females and 33% of males from T-hatchery reaching the smolt stage.The threshold sizes for smolt individuals in the outdoor mesocosm groups were also investigated; these were found to be 124mm for females and 162mm for males from K-hatchery, and 108mm for females and 119cm for males from T-hatchery, respectively. On the other hand, of the juveniles that were released into natural streams, the combined total of females that exceeded the threshold size from both hatcheries was only 8 out of 304 individuals recaptured from the same section.These research results strongly indicate that the vast majority of released salmonids experience reduced growth in natural rivers, meaning that they are unable to exceed the threshold size necessary to become smolts.This study has shown that if captive-bred salmonid fish are released into natural rivers prior to smoltification they are highly unlikely to become migratory, even if their phenotypes are expressed in a hatchery. The results thus indicate that releasing large numbers of juvenile individuals doesn't really contribute to the replenishment and conservation of migratory salmon stocks.However, if these fish are raised in a hatchery environment that is similar to a natural river, there is a possibility that fish could be produced that can grow well even after being released. In addition, it may be possible to increase the number of migratory fish by protecting and restoring streams and their surrounding forest environments, which could improve the growth of fish in the wild.Currently, the research group is conducting field experiments in order to improve the growth rate of captive-bred red-spotted masu salmon in rivers and to illuminate the environment required for individuals to become migratory. At the same time, they are also planning to investigate methods of reclaiming river environments that can support the growth of migratory phenotypes, without relying on stocking practices.
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Zoology
| 2,021 |
February 4, 2021
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https://www.sciencedaily.com/releases/2021/02/210204120100.htm
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Fast-flying bats rely on late-night updrafts to reach great heights
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Although scientists knew that some bats could reach heights of over 1,600 meters (or approximately one mile) above the ground during flight, they didn't understand how they managed to do it without the benefit of thermals that aren't typically available to them during their nighttime forays. Now, researchers reporting in the journal
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It turns out that the European free-tailed bats they studied -- powerful fliers that the researchers documented sometimes reaching speeds of up to 135 kilometers (84 miles) per hour in self-powered flight -- do depend on orographic uplift that happens when air is pushed up over rising terrain to help them fly high, just as birds do during the day. But, because that's harder to find during the cooler night, they have to rely on just the right sort of areas to reach those high altitudes."We show that wind and topography can predict areas of the landscape able to support high-altitude ascents, and that bats use these locations to reach high altitudes while reducing airspeeds," explains Teague O'Mara, of Southeastern Louisiana University and the Max Planck Institute of Animal Behavior. "Bats then integrate wind conditions to guide high-altitude ascents, deftly exploiting vertical wind energy in the nocturnal landscape."To make these discoveries, O'Mara and colleagues fitted the free-tailed bats with high-resolution GPS loggers that recorded their location in three-dimensional space every 30 seconds, tracking them for up to three days during the approximately six-hour night. The data show that bats emerge just after sunset and fly constantly throughout the night before returning to roost.They observed that the bats' flight would typically follow the terrain they crossed, but that occasionally they would climb to extreme heights, reaching nearly a mile above ground level in less than 20 minutes. During these high-altitude ascents, the bats would climb faster, longer, and at a lower airspeed than during more moderate ascents to around 300 meters. Most bats descended quickly after reaching their peak elevation, resulting in a kind of rollercoaster flight path.The researchers were surprised to discover just how predictable the bats' high-flying ascents were across the landscape. The data show that bats are using the same types of places -- although not necessarily always the exact same locations -- where the wind sweeps up a slope to carry them to high altitudes."We were ready to see that these bats flew fast, so that wasn't a surprise to us," O'Mara said. "But the fast, uplifting wind-supported flights were something our team really wasn't looking for or prepared for."The findings show that bats are solving the problems of flight in similar ways to birds -- just at night, the researchers note."These free-tailed bats seem to find ways to minimize how much energy they have to spend to find food each night," O'Mara said. "It's a pretty incredible challenge for an animal that can only really perceive the 30 to 50 meters ahead of it in detail. It takes a lot of energy to fly up to 1,600 meters above the ground, and these bats have found a way to ride the wind currents up."Although the researchers already had a pretty good idea based on past work that the bats also could fly amazingly fast, they say this fast-flying ability remains "a bit of an unsolved problem.""Their small body sizes and large, flexible wings covered in a thin membrane were assumed to prevent these really fast speeds," O'Mara said. "But it's now clear that bats can fly incredibly fast when they choose. It's up to us to figure out how they do that and if it can be applied to other scenarios," such as engineering bio-inspired high-speed and low-energy flight.
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Zoology
| 2,021 |
February 3, 2021
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https://www.sciencedaily.com/releases/2021/02/210203090458.htm
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Childhood diet has lifelong impact
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Eating too much fat and sugar as a child can alter your microbiome for life, even if you later learn to eat healthier, a new study in mice suggests.
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The study by UC Riverside researchers is one of the first to show a significant decrease in the total number and diversity of gut bacteria in mature mice fed an unhealthy diet as juveniles."We studied mice, but the effect we observed is equivalent to kids having a Western diet, high in fat and sugar and their gut microbiome still being affected up to six years after puberty," explained UCR evolutionary physiologist Theodore Garland.A paper describing the study has recently been published in the The microbiome refers to all the bacteria as well as fungi, parasites, and viruses that live on and inside a human or animal. Most of these microorganisms are found in the intestines, and most of them are helpful, stimulating the immune system, breaking down food and helping synthesize key vitamins.In a healthy body, there is a balance of pathogenic and beneficial organisms. However, if the balance is disturbed, either through the use of antibiotics, illness, or unhealthy diet, the body could become susceptible to disease.In this study, Garland's team looked for impacts on the microbiome after dividing their mice into four groups: half fed the standard, 'healthy' diet, half fed the less healthy 'Western' diet, half with access to a running wheel for exercise, and half without.After three weeks spent on these diets, all mice were returned to a standard diet and no exercise, which is normally how mice are kept in a laboratory. At the 14-week mark, the team examined the diversity and abundance of bacteria in the animals.They found that the quantity of bacteria such as Muribaculum intestinale was significantly reduced in the Western diet group. This type of bacteria is involved in carbohydrate metabolism.Analysis also showed that the gut bacteria are sensitive to the amount of exercise the mice got. Muribaculum bacteria increased in mice fed a standard diet who had access to a running wheel and decreased in mice on a high-fat diet whether they had exercise or not.Researchers believe this species of bacteria, and the family of bacteria that it belongs to, might influence the amount of energy available to its host. Research continues into other functions that this type of bacteria may have.One other effect of note was the increase in a highly similar bacteria species that were enriched after five weeks of treadmill training in a study by other researchers, suggesting that exercise alone may increase its presence.Overall, the UCR researchers found that early-life Western diet had more long-lasting effects on the microbiome than did early-life exercise.Garland's team would like to repeat this experiment and take samples at additional points in time, to better understand when the changes in mouse microbiomes first appear, and whether they extend into even later phases of life.Regardless of when the effects first appear, however, the researchers say it's significant that they were observed so long after changing the diet, and then changing it back.The takeaway, Garland said, is essentially, "You are not only what you eat, but what you ate as a child!"
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Zoology
| 2,021 |
January 27, 2021
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https://www.sciencedaily.com/releases/2021/01/210127093217.htm
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Newly discovered fossil, likely subaqueous insect
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A newly discovered trace fossil of an ancient burrow has been named after University of Alberta paleontologist Murray Gingras. The fossil, discovered by a former graduate student, has an important role to play in gauging how salty ancient bodies of water were, putting together a clearer picture of our planet's past.
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"Naming the fossil after Gingras was a straightforward decision since his research focuses on tying modern observations of how salinity and substrate affect organism burrowing to ancient burrow appearance and species abundance trends."Trace fossils are a type of fossil that preserves activity of ancient life in the geological record. They include fossilized footprints, nests, droppings and, in this case, a fossilized burrow dug by an organism that lived in a watery environment.The fossilized burrow, named Glossifungites gingrasi, is from the late Cretaceous of central Utah and was home to water-dwelling insects, similar to mayflies, more than 90 million years ago."Fossils like this are significant because they help us narrow down what type of organism dug the burrow -- which in turn will tell us about the salinity of the water in which they lived," said King.Many organisms make use of burrows for shelter and protection while they feed. These animal-constructed sedimentary structures give researchers a clearer picture of biological communities and are important in understanding ancient rivers, bays, estuaries and oceans through their oxygenation levels and saltiness, King explained.Murray Gingras, professor in the Department of Earth and Atmospheric Sciences, was the co-advisor for King's doctoral studies and for the master's degree of another researcher on the team, Andrew La Croix, now an assistant professor at the University of Waikato."I was surprised and honoured," said Gingras of the recognition. "I have been recognized with a few different awards over the years, but nothing really came close to the pride and elation I felt when Ryan informed me that he and Andrew formally named a trace fossil for me."
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Zoology
| 2,021 |
January 19, 2021
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https://www.sciencedaily.com/releases/2021/01/210119122109.htm
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Study identifies a nonhuman primate model that mimics severe COVID-19 similar to humans
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Aged, wild-caught African green monkeys exposed to the SARS-CoV-2 virus developed acute respiratory distress syndrome (ARDS) with clinical symptoms similar to those observed in the most serious human cases of COVID-19, report researchers in
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"Animal models greatly enhance our understanding of diseases. The lack of an animal model for severe manifestations of COVID-19 has hampered our understanding of this form of the disease," explained lead investigator Robert V. Blair, DVM, PhD, Dip ACVP, Tulane National Primate Research Center, Covington, LA, USA. "If aged green monkeys prove to be a consistent model of severe COVID-19, studying the disease pathobiology in them would improve our understanding of the disease and allow testing treatment options."The researchers exposed four aged rhesus macaques and four aged African green monkeys to SARS-CoV-2. Older animals (13-16 years of age) were specifically chosen to see if they would develop the severe form of the disease that is observed more frequently in elderly individuals. All of the monkeys developed a spectrum of disease from mild to severe COVID-19. A day after routine screening found no remarkable symptoms, two of the African green monkeys developed rapid breathing that quickly progressed to severe respiratory distress. Radiographic studies found the two African green monkeys had widespread opacities in the lungs, in stark contrast to images taken the day before, highlighting the rapid development of the disease. Such opacities are a hallmark of ARDS in humans.The African green monkeys that progressed to severe disease had notable increases in plasma cytokines that are compatible with cytokine storm, which is thought to underlie the development of ARDS in some patients. All four African green monkeys had elevated levels of interferon gamma; the two that had progressed to ARDS had the highest plasma concentration. Plasma cytokines were not increased in the rhesus macaques. Dr. Blair suggested that elevated interferon gamma could be explored as a potential predictive biomarker for advanced disease in patients and a possible therapeutic target.Dr. Blair said, "Our data suggest that both rhesus monkeys and African green monkeys are capable of modeling mild manifestations of SARS-CoV-2 infection, and aged African green monkeys may additionally be capable of modeling severe disease manifestations, including ARDS."
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Zoology
| 2,021 |
January 15, 2021
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https://www.sciencedaily.com/releases/2021/01/210115091346.htm
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Guppies have varying levels of self-control
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Just like humans trying to stick to New Year's resolutions, guppies have varying levels of self-control, a new study shows.
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Researchers from the University of Exeter and Ghent University studying the behaviours of Trinidadian guppies tested "inhibitory control" (suppressing unhelpful impulses or urges). The tiny fish first learned how to swim into a cylinder to get food -- then a cover was removed to make the cylinder transparent.Inhibitory control was measured by whether a guppy resisted the urge to swim directly towards the food -- bumping into the cylinder -- or still swam around, relying on previous learning.The findings revealed "consistent individual variation" -- some guppies had more self-control than others."Studies of inhibitory control have traditionally focussed on a few bird and mammal species, but we now know it exists in a wide range of animals," said Dr Alessandro Macario, of Exeter's Centre for Research in Animal Behaviour."As well as finding consistent differences between individual guppies, the population of guppies we studied were, on average, half as able to control impulses as a different strain of guppies tested in a previous study under similar conditions."We can't be certain about the causes of this difference, but it's possible that the strain we studied had evolved in different social and environmental conditions -- with less need for inhibitory control."The study examined captive females, with each guppy tested multiple times.In total, the fish inhibited the urge to swim directly at the food in 28.5% of trials.No improvement was seen over time, but the researchers say this might have occurred if the guppies had been tested for longer.Professor Darren Croft, also of the University of Exeter, said: "Our study is a first step towards understanding how inhibitory control has evolved in guppies."Guppies live in small rivers alongside predators so, for example, they might need the ability to hide and resist the urge to leave that hiding place to get food."The next step in this research is to examine the extent to which this trait affects guppies' chances of survival or reproduction."
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Zoology
| 2,021 |
January 14, 2021
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https://www.sciencedaily.com/releases/2021/01/210114111916.htm
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Micro-climate molds and reshapes northern insect communities, herbivory and predation
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Climate and changes in it have direct impacts on species of plant and animals -- but climate may also shape more complex biological systems like food webs. Now a research group from the University of Helsinki has investigated how micro-climate shapes each level of the ecosystem, from species' abundances in predator communities to parasitism rates in key herbivores, and ultimately to damage suffered by plants. The results reveal how climate change may drastically reshape northern ecosystems.
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Understanding the impact of climatic conditions on species interactions is imperative, as these interactions include such potent ecological forces as herbivory, pollination and parasitism.Lead researcher Tuomas Kankaanpaa from the Faculty of Agriculture and Forestry, University of Helsinki, investigated how insect communities are assembled along micro-climatic gradients found on a mountainside in Northeast Greenland. He then compared this variation in environmental conditions to variation in the structure and function of different compartments of a food web. This web consists of a flowering plant as the primary producer (mountain avens), of moth larvae feeding on the flowers as consumers, and of parasitic wasps and flies, which, in turn, use moth larvae as living nurseries for their own offspring.The study identified the micro-climate as an important factor in determining the local structure of parasitoid communities. Even within the uniform focal habitat type (heathland dominated by mountain avens), the abundances of species and the strengths interspecific interactions changed with climatic factors. As parasitoids are fairly specialized predators, they are particularly sensitive to environmental changes."To understand the more general impact of climate, we cannot always go species-by-species in each area. Rather, we need to uncover the uniting characteristics of species which show similar responses to climatic conditions," explains Kankaanpaa.For the parasitoid insects of the North, one key trait turned out to be the way in which parasitoid species use their hosts. Species that spend considerable time dormant inside of their host, waiting for it to grow, form one group: they tend to prefer sites on which snow melts early and summers which are hot and dry. Conversely, species that attack full-sized host larvae or pupae appear to do better at sites where thicker snow cover offers protection from cold winter temperatures.The larvae of the dominant avens-feeding moth species also preferred warm and dry areas in the landscape. The same association was evident in a long time-series collected as a part of an ongoing monitoring program at the Zackenberg research station. During the past two decades, winters with thin snow cover and warm summers have resulted in an increased proportion of avens flowers being consumed.A potentially serious consequence of climate change is a phenological mismatch -- i.e. a situation in which the seasonality of interacting species change at a different rate. This can lead to situations where e.g. herbivorous insects escape some of their predators in time, thereby allowing herbivore populations to grow. The researchers found that the two dominant parasitoids preying on the focal moth larvae showed distinctly different temporal relationships with their host. One of the parasitoids matched the flowering of mountain avens and the development of its host larvae near perfectly across the wide range of spring arrival recorded within the study area. Yet, the other parasitoid species proved only loosely trimmed to coincide with specific life stages of its host. Such shifts can make a big difference once two parasitoids occupy the same host individual and competition within the still-living food source becomes physical. If one is then at the right stage and the other not, this can affect the outcome of the game."The parasitoids communities of the far North have previously received little attention. This is surprising, as these communities are species-poor, and thereby offer excellent opportunities to study what factors influence how species come together and interact," says Kankaanpaa.The research group behind the study bridges two countries and two universities, the University of Helsinki and the Swedish University of Agricultural Sciences (SLU). It is led by Professor Tomas Roslin. The group has studied insect interactions across the world and in Greenland and regards the Arctic as an ideal observatory for monitoring the effects of climate change. In the High Arctic, the climate is changing especially fast -- and within this zone, North East Greenland offers a region where other human impacts are minimal, thereby allowing researchers to isolate the unique effects of climate.How insect communities vary along landscape-level micro-climates provides clues as to how such communities may change with time. Kankaanpää stresses that there is much work to be done before we can fully understand how climate change will reverberate through networks of live interactions. Do, for example, the outbreaks of a single herbivore species pose direct risks to those other herbivores with which it happens to share parasitoids? Can the feeding of large hoards of the joint enemies eventually extirpate the rarer host?
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Zoology
| 2,021 |
January 13, 2021
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https://www.sciencedaily.com/releases/2021/01/210113180605.htm
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Pulsed ultraviolet light technology to improve egg safety, help poultry industry
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Pulsed ultraviolet light can be an effective alternative to some of the antimicrobial technologies now used by the poultry industry to kill pathogens on eggshells, according to Penn State researchers, who simulated production conditions to test the technology.
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Researcher Paul Patterson, professor of poultry science, College of Agricultural Sciences, suggests the technology has merit for commercial application in the egg industry."This study is unique because it scaled-up and applied components of standard egg processing to a conveyor and sanitizing eggs in a commercial setting," he said. "In the absence of water or other chemical sanitizers, this technology has the potential to achieve significant -- equal or greater -- microbial reductions than some currently available technologies."Every year in the United States, an average of 287 eggs are consumed per person, and more than 14.1 billion eggs are set in hatchery incubators to produce chicks destined for the egg and meat bird industries. By reducing the microbial load on eggs, foodborne illness outbreaks associated with eggs and poultry meat can be reduced while chick health is maintained.The egg industry currently uses sanitizers and detergents to decontaminate eggs and wash off any physical debris, while low-intensity ultraviolet light has been used as an additional antimicrobial step. However, pulsed ultraviolet light is more effective, explained lead researcher Josh Casser, doctoral candidate in animal science, because it delivers a higher intensity of ultraviolet light to the surface of the eggshell. That results in a greater microbial reduction in a shorter period of time than conventional ultraviolet light treatment.In this study, the surfaces of shell eggs were inoculated with nonpathogenic bacteria strains used for research and were treated with pulsed ultraviolet light derived from a xenon flashlamp. Eggs were exposed on a modified egg-carrying conveyor that provided complete rotation of eggs under the flashlamp.The novel conveyor devised for the experiment was instrumental in achieving acceptable decontamination, Casser noted, adding that the xenon flashlamps could be scaled up and customized for any commercial installation."As the egg rotates on its long axis along the way, the entire surface of the eggshell is exposed to the pulsed ultraviolet light energy, and the 27 seconds of exposure in our experiment resulted in an acceptable germicidal response," he said. "At three pulses per second, each egg is exposed to nearly 90 pulses, and each pulse has a duration of 360 microseconds -- an extremely short duration pulse."The researchers, who recently published their results in The study also evaluated the effects of pulsed ultraviolet light treatment of hatching eggs on both embryo and chick growth. Using the same system, four batches of 125 fertile eggs were treated with the same and greater intensities of pulsed ultraviolet light. After processing, eggs were placed in a commercial incubator under normal incubation conditions.There was no significant effect of the pulsed ultraviolet light treatment on percent fertility, hatchability or hatch. Also, there were no significant effects on post-hatch observations, including chick livability and average bird weight at hatch or at 42 days of age."Our research supports the application of pulsed ultraviolet light as an effective antimicrobial intervention for both table and hatching eggs," Cassar said. "If the egg industry embraces pulsed ultraviolet light technology and applies it in its processing operations, food safety would be improved because of the reduced pathogen presence on the surface of the eggs. And that matters because 9% of all foodborne illness in the U.S. is associated with eggs."The technology is especially promising because it appears to have no negative consequences for the vital hatching-eggs component of the business, even at 10 times the UV-light intensity used in the table egg study, Patterson pointed out. Hatcheries produce the replacement stock for both the egg and broiler flocks of the poultry industry, including turkeys."Our research showed that there are no negative effects on hatching eggs and the embryos and chicks that are derived from those treated eggs," he said. "Using pulsed ultraviolet light before incubation in a hatchery setting would improve chick health, would avoid some of the financial constraints caused by poor chick quality resulting from chicks getting sick from early exposure to microbial pathogens, and potentially would improve the food safety of poultry meat."
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Zoology
| 2,021 |
January 11, 2021
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https://www.sciencedaily.com/releases/2021/01/210111112149.htm
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More management measures lead to healthier fish populations
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Fish populations tend to do better in places where rigorous fisheries management practices are used, and the more measures employed, the better for fish populations and food production, according to a new paper published Jan. 11 in
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The study, led by Michael Melnychuk of the University of Washington's School of Aquatic and Fishery Sciences, draws upon the expertise of more than two dozen researchers from 17 regions around the world. The research team analyzed the management practices of nearly 300 fish populations to tease out patterns that lead to healthier fisheries across different locations. Their findings confirmed, through extensive data analysis, what many researchers have argued for several years."In general, we found that more management attention devoted to fisheries is leading to better outcomes for fish and shellfish populations," Melnychuk said. "While this won't be surprising to some, the novelty of this work was in assembling the data required and then using statistical tools to reveal this pattern across hundreds of marine populations."The research team used an international database that is the go-to scientific resource on the status of more than 600 individual fish populations They chose to analyze 288 populations that generally are of value economically and represent a diversity of species and regions. They then looked over time at each fish population's management practices and were able to draw these conclusions:The study builds on previous work that found, by using the same database, that nearly half of the fish caught worldwide are from populations that are scientifically monitored and, on average, are increasing in abundance. The new paper takes a closer look at specific management actions and how they have impacted fishing pressure and the abundance of each population examined, Melnychuk explained."All fish populations have their own unique contexts that might dictate what management tools would be most helpful and promising to use," he said. "Despite the great diversity in their management objectives and various strategies to meet those, we focused on key management tools in common to many fisheries around the world."The international research team chose to look at a spectrum of fish populations, such as hakes in South Africa and Europe, orange roughy in New Zealand, tuna species on the high seas, anchovies in South America and scallops off the Atlantic coast of North America. Most of the populations they examined had a history of being depleted at some point, usually due to historical overfishing.For example, with U.S. mid-Atlantic population of black sea bass, a rebuilding plan instituted in 1996 brought fishing rates down from three times the sustainable level to below this mark, which led to a steady rebuilding of the fishery and full recovery by 2009."Fishers targeting black sea bass in the northeastern U.S. are finally reaping the rewards of harvest caps that allowed the population to rebuild," said co-author Olaf Jensen of the University of Wisconsin -- Madison. "The 2020 catch limit of more than 6,000 tons is the highest since catch limits were first imposed more than 20 years ago."This analysis omits fisheries that lack scientific estimates of population status, even though these account for a large amount of the world's catch. These include most of the fish populations in South Asia and Southeast Asia -- fisheries in India, Indonesia and China alone represent 30% to 40% of the world's catch, most of which is essentially unassessed. Although fisheries in these regions could not be included in the analyses, the paper's authors conclude that lessons learned can equally apply to data-limited fisheries: Greater investment in fisheries management systems is expected to lead to better outcomes for the fish populations upon which our fisheries are based.A full list of paper co-authors is available in the paper. This research was funded by The Nature Conservancy, The Wildlife Conservation Society, the Walton Family Foundation and a consortium of Seattle fishing companies.
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Zoology
| 2,021 |
December 24, 2020
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https://www.sciencedaily.com/releases/2020/12/201224084406.htm
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Early mammal with remarkably precise bite
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Paleontologists at the University of Bonn (Germany) have succeeded in reconstructing the chewing motion of an early mammal that lived almost 150 million years ago. This showed that its teeth worked extremely precisely and surprisingly efficiently. Yet it is possible that this very aspect turned out to be a disadvantage in the course of evolution. The study is published in the journal
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At just twenty centimeters long, the least weasel is considered the world's smallest carnivore alive today. The mammal that researchers at the University of Bonn have now studied is unlikely to have been any bigger. However, the species to which it belongs has long been extinct: Priacodon fruitaensis (the scientific name) lived almost 150 million years ago, at a time when dinosaurs dominated the animal world and the triumph of mammals was still to come.In their study, the paleontologists from the Institute for Geosciences at the University of Bonn analyzed parts of the upper and lower jaw bones of a fossil specimen. More precisely: its cheek teeth (molars). Because experts can tell a lot from these, not only about the animal's diet, but also about its position in the family tree. In P. fruitaensis, each molar is barely larger than one millimeter. This means that most of their secrets remain hidden from the unarmed eye.The researchers from Bonn therefore used a special tomography method to produce high-resolution three-dimensional images of the teeth. They then analyzed these micro-CT images using various tools, including special software that was co-developed at the Bonn-based institute. "Until now, it was unclear exactly how the teeth in the upper and lower jaws fit together," explains Prof. Thomas Martin, who holds the chair of paleontology at the University of Bonn. "We have now been able to answer that question."The upper and lower jaws each contain several molars. In the predecessors of mammals, molar 1 of the upper jaw would bite down precisely on molar 1 of the lower jaw when chewing. In more developed mammals, however, the rows of teeth are shifted against each other. Molar 1 at the top therefore hits exactly between molar 1 and molar 2 when biting down, so that it comes into contact with two molars instead of one. But how were things in the early mammal P. fruitaensis?"We compared both options on the computer," explains Kai Jäger, who wrote his doctoral thesis in Thomas Martin's research group. "This showed that the animal bit down like a modern mammal." The researchers simulated the entire chewing motion for both alternatives. In the more original version, the contact between the upper and lower jaws would have been too small for the animals to crush the food efficiently. This is different with the "more modern" alternative: In this case, the cutting edges of the molars slid past each other when chewing, like the blades of pinking shears that children use today for arts and crafts.Its dentition therefore must have made it easy for P. fruitaensis to cut the flesh of its prey. However, the animal was probably not a pure carnivore: Its molars have cone-shaped elevations, similar to the peaks of a mountain. "Such cusps are particularly useful for perforating and crushing insect carapaces," says Jäger. "They are therefore also found in today's insectivores." However, the combination of carnivore and insectivore teeth is probably unique in this form.The cusps are also noticeable in other ways: They are practically the same size in all molars. This made the dentition extremely precise and efficient. However, these advantages came at a price: Small changes in the structure of the cusps would probably have dramatically worsened the chewing performance. "This potentially made it more difficult for the dental apparatus to evolve," Jäger says.This type of dentition has in fact survived almost unchanged in certain lineages of evolutionary history over a period of 80 million years. At some point, however, its owners became extinct -- perhaps because their teeth could not adapt to changing food conditions.
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Zoology
| 2,020 |
December 23, 2020
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https://www.sciencedaily.com/releases/2020/12/201223091547.htm
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Highest levels of microplastics found in molluscs, new study says
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Mussels, oysters and scallops have the highest levels of microplastic contamination among seafood, a new study reveals.
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The research -- led by researchers at Hull York Medical School and the University of Hull -- looked at more than 50 studies between 2014 and 2020 to investigate the levels of microplastic contamination globally in fish and shellfish.Scientists are still trying to understand the health implications for humans consuming fish and shellfish contaminated with these tiny particles of waste plastic, which finds its ways into waterways and oceans through waste mismanagement.Study author, Evangelos Danopoulos, a postgraduate student at Hull York Medical School said: "No-one yet fully understands the full impact of microplastics on the human body, but early evidence from other studies suggest they do cause harm."A critical step in understanding the full impact on human consumption is in first fully establishing what levels of microplastics humans are ingesting. We can start to do this by looking at how much seafood and fish is eaten and measuring the amount of MPs in these creatures."The study shows microplastic content was 0-10.5 microplastics per gram (MPs/g) in molluscs, 0.1-8.6 MPs/g in crustaceans, 0-2.9 MPs/g in fish.The latest consumption data in the research shows China, Australia, Canada, Japan and the US are amongst the largest consumers of molluscs, followed by Europe and the UK.Molluscs collected off the coasts of Asia were the most heavily contaminated with researchers suggesting that these areas are more heavily polluted by plastic.Evangelos Danopoulos added: "Microplastics have been found in various parts of organisms such as the intestines and the liver. Seafood species like oysters, mussels and scallops are consumed whole whereas in larger fish and mammals only parts are consumed. Therefore, understanding the microplastic contamination of specific body parts, and their consumption by humans, is key."Plastic waste generated worldwide is expected to triple to 155-265 million metric tonnes per year by 2060. Once the plastic finds its way into oceans, lakes and rivers it has the potential to end up as microplastic inside shellfish, fish and marine mammals.The research points to the need to standardise methods of measuring microplastic contamination so that different measurements can be more readily compared. Researchers said more data is needed from different parts of the world to understand how the issue varies between different oceans, seas and waterways.
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Zoology
| 2,020 |
December 22, 2020
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https://www.sciencedaily.com/releases/2020/12/201222141531.htm
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Mouse-controlled mouse helps researchers understand intentional control
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We know that the brain can direct thoughts, but how this is achieved is difficult to determine. Researchers at the Sainsbury Wellcome Centre have devised a brain machine interface (BMI) that allows mice to learn to guide a cursor using only their brain activity. By monitoring this mouse-controlled mouse moving to a target location to receive a reward, the researchers were able to study how the brain represents intentional control.
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The study, published today in "Brain machine interfaces are devices that allow a person or animal to control a computer with their mind. In humans, that could be controlling a robotic arm to pick up a cup of water, or moving a cursor on a computer to type a message using the mind. In animals, we are using these devices as models for understanding how to make BMIs better," said the paper's first author, Dr Kelly Clancy, who completed the study at the Sainsbury Wellcome Centre, University College London, following previous work at Biozentrum, University of Basel."Right now, BMIs tend to be difficult for humans to use and it takes a long time to learn how to control a robotic arm for example. Once we understand the neural circuits supporting how intentional control is learned, which this work is starting to elucidate, we will hopefully be able to make it easier for people to use BMIs," said co-author of the paper, Professor Tom Mrsic-Flogel, Director of the Sainsbury Wellcome Centre, University College London.Traditionally it has been difficult to study how causally-controlled objects are represented in the brain. Imagine trying to determine how the brain represents a cursor it is controlling versus a cursor it is passively watching. There are motor signals in the first case but not in the second, so it is difficult to compare the two. With BMIs, the subject doesn't physically move, so a cleaner comparison can be made.In this study, the researchers used a technique called widefield brain imaging, which allowed them to look at the whole dorsal surface of the cortex while the animal was using the BMI. This technique enabled an unbiased screen of the cortex to locate the areas that were involved in learning to intentionally control the cursor.Visual cortical areas in mice were found to be involved during the task. These areas included the parietal cortex, an area of the brain implicated in intention in humans."Researchers have been studying the parietal cortex in humans for a long time. However, we weren't necessarily expecting this area to pop out in our unbiased screen of the mouse brain. There seems to be something special about parietal cortex as it sits between sensory and motor areas in the brain and may act as a way station between them," added Dr Kelly Clancy.By delving deeper into how this way station works, the researchers hope to understand more about how control is exerted by the brain. In this study, mice learned to map their brain activity to sensory feedback. This is analogous to how we learn to interact with the world -- for example, we adjust how we use a computer mouse depending on its gain setting. Our brains build representations of how objects typically behave, and execute actions accordingly. By understanding more about how such rules are generated and updated in the brain, the researchers hope to be able to improve BMIs.
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Zoology
| 2,020 |
December 21, 2020
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https://www.sciencedaily.com/releases/2020/12/201221101226.htm
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Study resolves the position of fleas on the tree of life
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A study of more than 1,400 protein-coding genes of fleas has resolved one of the longest standing mysteries in the evolution of insects, reordering their placement in the tree of life and pinpointing who their closest relatives are.
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The University of Bristol study, published in the journal The findings overturn previously held theories about fleas, the unusual anatomy of which has meant that they eluded classification in evolutionary terms. According to the authors of the study, contrary to popular belief, fleas are technically scorpionflies, which evolved when they started feeding on the blood of vertebrates sometime between the Permian and Jurassic, between 290 and 165 million years ago.The closest living relatives of fleas are the members of the scorpionfly family Nannochoristidae, a rare group with only seven species native to the southern hemisphere. Unlike the blood-thirsty fleas, adult nannochoristid scorpionflies lead a peaceful existence feeding on nectar."Of all the parasites in the animal kingdom, fleas hold a pre-eminent position. The Black Death, caused by a flea-transmitted bacterium, was the deadliest pandemic in the recorded history of humankind; it claimed the lives of possibly up to 200 million people in the 14th century," says lead author and undergraduate student Erik Tihelka from the School of Earth Sciences."Yet despite their medical significance, the placement of fleas on the tree of life represents one of the most persistent enigmas in the evolution of insects."It used to be thought that all blood-feeding parasitic insects began life as either predators or by living alongside vertebrate hosts in their nests. In actual fact, blood feeding can evolve in groups that originally fed on nectar and other plant secretions."It seems that the elongate mouthparts that are specialized for nectar feeding from flowers can become co-opted during the course evolution to enable sucking blood," says Mattia Giacomelli, a PhD student at the University of Bristol who participated in the study.Previous studies had suggested a connection between fleas and anatomically unusual groups of scorpionflies, but their exact relationships remained unresolved. The mystery was prolonged by the fact that flea genomes underwent rapid evolution, which makes reconstructing ancient evolutionary relationships challenging. Moreover, the nannochoristids are a quite rare and little-studied group that only occurs in New Zealand, southeastern Australia, Tasmania, and Chile, so they are easy to overlook."The new results suggest that we may need to revise our entomology textbooks. Fleas no longer deserve the status of a separate insect order, but should actually be classified within the scorpionflies," says Chenyang Cai, associate professor at the Nanjing Institute of Geology and Palaeontology (NIGP) and a research fellow at the University of Bristol specialising on Mesozoic insects."We have exceptionally preserved fossil fleas from the Jurassic and Cretaceous. In particular, some Jurassic fleas from China, about 165 million years old, are truly giant and measure up to two centimetres. They may have fed on dinosaurs, but that is exceedingly difficult to tell. What is more interesting is that these ancient fleas share important characters with modern scorpionflies."
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Zoology
| 2,020 |
December 16, 2020
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https://www.sciencedaily.com/releases/2020/12/201216134711.htm
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Biodiversity collections, vital for pandemic preparedness, face drop in specimen deposits
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When you imagine a visit to a natural history museum, the first thing that springs to mind could be dinosaur bones or taxidermized animals.
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Behind the visitor displays, however, advanced research on specimens collected from around the world is taking place. What's more, this work forms an essential front line of defense in pandemic preparedness.According to Jocelyn Colella, research affiliate with the University of Kansas Biodiversity Institute and incoming assistant curator of mammals with the KU Natural History Museum, museums act as a kind of decentralized pathogen surveillance network. In a recent piece published in "Museum visitors see specimens on display, but hundreds and thousands of others are safely preserved behind the scenes -- museum curators are responsible for making sure that those specimens are preserved and available for research going into the future," she said. "Fifty years ago, we weren't sequencing DNA. But now we are -- and specimens preserved over decades, or even centuries, can now be used for molecular research. We have a couple of liquid nitrogen dewars here at the Biodiversity Institute that hold frozen tissues from all sorts of animals, from all over the world. Those tissues can be used to sequence whole genomes to identify how animals are adapting or responding to changing conditions."Colella said such collections preserve specimens and also capture the community of microorganisms that use the organism as a host."You can also sequence viruses, bacteria and fungi from all of those frozen tissues -- so you not only get information on the host organism or mammal, but you also get information about their entire community," she said.Because more than half of all emerging diseases in humans come from wildlife, such as COVID-19 (which scientists think jumped to humans from horseshoe bats), museum specimens hold the genetic clues needed to determine where they came from and better understand and fight these pathogens -- especially in countries at high risk for emerging zoonotic disease, such as those with high species diversity and a high frequency of human-wildlife contact."As the human population grows, we continue to come into contact with new, different and more animals. That increases the risk of these disease spillover events," Colella said. "The cool thing with natural history museum collections is that we have sampling through time. You can survey the same areas over and over, sampling all sorts of different animals, which gives us a sense of how long a virus has been there and where it came from."The KU researcher pointed to hantavirus as an example where biodiversity collections collaborated with the Centers for Disease Control to help fight off a disease that had entered the human population from animals."Parallel to the current COVID-19 pandemic, there was a spillover event in 1993 of hantavirus in the American Southwest that led to the deaths of many people, and we had no idea where it came from," Colella said. "The CDC asked the Museum of Southwestern Biology to help find the reservoir host of the virus, and they identified deer mice as the source. Researchers were then able to go back into these historic mammal collections and found that this disease had been in rodent populations for over 10 years before it spilled over into humans. That type of information allows us to have an evolutionary perspective on what happened between when this virus emerged in rodents and when it became harmful to humans -- what changed? That allows us to respond and prevent outbreaks in the future."While the importance of natural history museums to human health has never been higher, in recent years the number of specimens being deposited in biodiversity collections actually has been declining.A second paper written by Colella and colleagues, just published in "Another reason scientists are having trouble identifying reservoir hosts and finding novel viruses is because the sampling base in museums just isn't there, and it's not because scientists aren't taking samples," she said. "It's because there are no requirements for samples to land at museums or public institutions. There's an ethical issue with collecting animals and then keeping all those samples in your personal freezer forever until you retire or lose all the IDs and can't associate the material with XYZ, and it was all for naught. We can do better."According to Colella, several studies have tracked the number of deposited specimens across the past few decades and show "dramatic declines" starting in the late 1990s. "There are plenty of permits out there and specimens being sampled. The samples are just not ending up in museums," she said.The KU researcher and her co-authors propose treating specimens collected in the field exactly like other types of scientific data and using the open-data model to ensure scientists have access to museum specimens for research today and into the future."We propose increased open-data requirements by journals, integration of specimens into existing requirements for data management plans and a cultural shift in biological sciences. That must be collectively propelled by researchers, editors and reviewers as part of the solution," Colella said.She differentiates between the ideas of specimen "ownership" and "stewardship.""Specimen stewardship promotes the democratization of specimens to maximize access and research potential through the use and re-use of specimens' resources to answer multiple scientific questions, instead of private ownership for use in a single project," Colella said. "If samples never get archived with a museum, it's a loss to the entire scientific community. We're saying if you have private specimen collections, there needs to be a plan to get those samples archived eventually, so that if you're not around anymore or you need someone else to archive them, they know what to do. There needs to be a plan from the very beginning when the specimens are collected. Stewardship is making sure that the resources you're collecting are taken care of into the future and museum exist to do just that."
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Zoology
| 2,020 |
December 15, 2020
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https://www.sciencedaily.com/releases/2020/12/201215095927.htm
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Genome sequencing paves the way for more sustainable herring fishery
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An international team of Swedish, Norwegian, Danish and Irish scientists has used whole genome sequencing to characterise 53 herring populations from the Atlantic Ocean and the Baltic Sea. They have developed genetic markers that make it possible to better monitor herring populations and avoid overfishing. The study is published in the journal
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"This project provides a 'toolbox' in the form of genetic markers for cost-effective screenings that can be applied to monitor herring stocks throughout their life history from the larval stage to the adult stage," concludes Professor Arild Folkvord of Bergen University, who led the GENSINC project, which this study is part of. "It will now be possible to distinguish different stocks when they are mixed on the feeding grounds, for instance, which will help set fishing quotas that harness sustainable exploitation of genetically defined stocks."The Atlantic herring is one of the most abundant vertebrates on Earth. It has been estimated that the total breeding stock of herring in the Atlantic Ocean and adjacent waters amounts to about one trillion fish.Herring constitute this enormous biomass because they feed on plankton. They in turn are an important food resource for other fish, seabirds and sea mammals like the fin whale. Herring fishery has been an important food resource since humans colonised Northern Europe. Herring are schooling fish and therefore susceptible to overfishing because many tonnes of herring can be caught in a single haul during fishing, and in the past several stocks of herring have collapsed due to overfishing.A grand challenge for the future is to avoid overfishing and maintain viable stocks of marine fish exploited in marine fishery. Stocks of herring are defined by where and when they spawn, but until now no efficient genetic markers have been available for distinguishing different stocks.When Professor Leif Andersson of Uppsala University, who has led the genetic analysis, first started to study the Atlantic herring in the late 1970s, only a handful of genetic markers could be used. To their surprise, scientists found that all the markers they analysed occurred at the same frequency across all populations of herring. The reason for this lack of genetic differences for most genes is that the population size is huge and there is gene flow between populations, making the frequencies of gene variants stable over time and space."In the present study we have sequenced the entire genome and studied millions of genetic variants," explains Dr Fan Han, a former PhD student at Uppsala University and first author on the article. "Now our resolution is completely different, we find very clear genetic differences for a limited number of genes that appear to distinguish all major stocks of Atlantic herring."The researchers found gene variants for a few hundred genes that are particularly important for the genetic adaptation to factors such as differences in spawning season, salinity and water temperature at spawning. These are the gene variants that are most useful to distinguish different stocks."The results of this study make Atlantic herring particularly well suited for studies on the impact of global warming on fish populations," explains Leif Andersson. "Some of the detected gene variants are strongly associated with water temperature at spawning. The gene variants that occur at a very high frequency in the waters surrounding Ireland and Great Britain, which are the warmest waters where herring reproduce, are expected to become more common further north as the seawater gets warmer."
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Zoology
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December 12, 2020
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https://www.sciencedaily.com/releases/2020/12/201212083333.htm
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Carrots are healthy, but active enzyme unlocks full benefits
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Carrots are a good source of beta-carotene, which is a precursor of vitamin A. But to get the full health benefits of this superfood, you need an active enzyme to produce this vitamin.
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Beta-carotene is the bioactive compound that gives carrots their orange color. Studies with humans and mice show the conversion of beta-carotene to vitamin A reduces "bad" cholesterol in the blood. Thus, beta-carotene can help protect against atherosclerosis development, which leads to the accumulation of fats and cholesterol in our arteries. Atherosclerosis cardiovascular disease is the primary cause of death worldwide, says Jaume Amengual, assistant professor of personalized nutrition in the Department of Food Science and Human Nutrition at University of Illinois.Amengual and his colleagues conducted two studies to further understand the effects of beta-carotene on cardiovascular health. They confirmed its importance, but identified a critical step in the process.Beta-carotene converts to vitamin A with the help of an enzyme called beta-carotene oxygenase 1 (BCO1). A genetic variation determines if you have a more or less active version of BCO1. People with a less active enzyme could need other sources for vitamin A in their diet, Amengual says.The first study, published in the "People who had a genetic variant associated with making the enzyme BCO1 more active had lower cholesterol in their blood. That was our first observation," Amengual notes.To follow up on these findings, Amengual and his colleagues conducted a second study, published in the "In the human study, we saw that cholesterol was higher in people who do not produce much vitamin A. To know if that observation has an effect in the long run, we would have to wait 70 years to see if they develop cardiovascular. In real life, that is not doable. That's why we use animals for certain studies, so we can speed up the process," he explains."The main findings of the mice study reproduce what we found in humans. We saw that when we give beta-carotene to mice, they have lower cholesterol levels. These mice develop smaller atherosclerosis lesions, or plaques, in their arteries. This means that mice fed beta-carotene are more protected against atherosclerosis than those fed a diet without this bioactive compound," Amengual states.In the second study, the researchers also investigated the biochemical pathways of these processes, determining where in the body the effect occurs."We narrow it down to the liver as the organ in charge of producing and secreting lipoproteins to the bloodstream, including those lipoproteins known as bad cholesterol. We observed that in mice with high levels of vitamin A, the secretion of lipids into the bloodstream slows down," Amengual notes.Understanding how the BCO1 enzyme relates to cholesterol has important implications. Typically, high beta-carotene levels in the blood are associated with health benefits. But it could also be a sign of a less active BCO1 enzyme that is not converting the beta-carotene we eat into vitamin A.Up to 50% of the population have the less-active variant of the enzyme, Amengual notes. That means their body is slower at producing vitamin A from a plant source, and they could need to get this nutrient directly from an animal source such as milk, or cheese, for example.
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Zoology
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