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This week’s news that Australian customs officers incinerated irreplaceable plant specimens has shocked botanists around the world, and left many concerned about possible impacts on international research exchanges. Some have put a freeze on sending samples to Australia until they are assured that their packages won’t meet a similar fate, and others are discussing broader ways of assuring safe passage of priceless specimens. "This story is likely to have a major chilling effect on the loan system between herbaria across national boundaries," says Austin Mast, president of the Society of Herbarium Curators and director of the herbarium at Florida State University in Tallahassee. "Without the free sharing of specimens, the pace of plant diversity research slows." As a result of the customs debacle, curators in New Zealand put a stay on shipping samples to Australia. So has the New York Botanical Garden in New York City, which holds the second largest collection of preserved plants in the world. "We, and many other herbaria, will not send specimens to Australia until we are sure this situation will not be repeated," says herbarium Director Barbara Thiers. Herbaria are guardians of plant biodiversity data. Around the world, about 3000 institutions keep a total of 350 million plants specimens that have been pressed, dried, and stored in cabinets. Some are hundreds of years old; others are rare examples of extinct species. Particularly valuable are so-called type specimens, used to describe species for the first time. Botanists consult these when they are identifying new species or revising taxonomy. Many herbaria have digitized images of their specimens, allowing initial research to be conducted remotely. But some details must be examined first-hand. To do that, biologists often request specimens through a kind of interlibrary loan. "The system works well when the risk of damage or destruction of loaned specimens is perceived to be very low," Mast says. But sometimes things go awry. Earlier this week, many botanists learned about the destruction of six type specimens of daisies—some collected during a French expedition to Australia from 1791 to 1793—which the National Museum of Natural History (NMNH) in Paris had mailed along with 99 other specimens to the Queensland Herbarium in Brisbane, Australia. After the package arrived in Brisbane in early January, the specimens were held up at customs because the paperwork was incomplete. Biosecurity officers asked the Queensland Herbarium for a list of the specimens and how they were preserved, but the herbarium sent its responses to the wrong email address, delaying the response by many weeks. In March, the officers requested clarification, but then incinerated the samples. "It's like taking a painting from the Louvre and burning it," says James Solomon, herbarium curator at the Missouri Botanical Garden in St. Louis. According to Australia’s Department of Agriculture and Water Resources, which enforces biosecurity rules, part of the problem was that the samples had a declared value of $2—and its agents routinely destroy low-value items that have been kept longer than 30 days. Michel Guiraud, director of collections at NMNH, says his museum's policy is to put minimal values on shipments. "If it is irreplaceable, there is no way to put an insurance value on it," he says. Guiraud says the package was sent with the usual documentation and he's trying to find out what went wrong. Concerned about the possibility of other scientific samples being destroyed, the museum is considering stopping loans from all of its collections to Australia. Australia’s agriculture department admitted in a statement that it erred in prematurely destroying the specimens, but didn't take sole responsibility for the snafu. "This is a deeply regrettable occurrence, but it does highlight the importance of the shared responsibility of Australia’s biosecurity system, and the need for adherence to import conditions." The department has reviewed its procedures for handling delayed items and is considering how package labels could highlight the “intrinsic value” of scientific specimens. On Monday, officials met with representatives from a consortium of Australasian herbaria to help them understand and comply with importation rules. "At this stage it appears we are resolving the matter very positively," says botanist Michelle Waycott of the University of Adelaide in Australia and the Council of Heads of Australasian Herbaria. A second incident came to light after botanists at the Allan Herbarium in Lincoln, New Zealand, heard last month about the destruction of the French specimens. They inquired about six lichen samples, including a type specimen of Buellia macularis, that they had shipped to the Australian National Herbarium in Canberra last year. It turned out the specimens had been destroyed in October 2016 by biosecurity officers in Sydney, Australia. The department is investigating what happened in this case. New Zealand herbaria have suspended loans to Australia while they wait for written guarantees that their specimens will be safe. “We are disappointed we have lost an important part of our collection but we’re looking forward to further international collaboration,” said Ilse Breitwieser, director of the Allan Herbarium, in a statement this week. Curators elsewhere are reviewing how they ship samples internationally. "We will rethink our policy of lending specimens to countries that would pose a risk for loss of collections," says Christine Niezgoda, collections manager of flowering plants at the Field Museum of Natural History in Chicago, Illinois, who, like others, was surprised to learn that specimens would be destroyed rather than returned. The Society for the Preservation of Natural History Collections, which is following the situation in Australia, hopes to increase communication among curators about shipping regulations and border inspection procedures. A long-standing frustration for many is that the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS), like its counterpart in Australia, does not have a separate category for low-risk scientific specimens. "The way that the U.S. and Australian governments are treating these shipments is basically going to bring taxonomic work to a halt," says Ellen Dean, curator of the Center for Plant Diversity at the University of California, Davis. "We are thinking of no longer loaning our specimens to other countries, because we are uncertain that APHIS will allow our own specimens back into this country." Whatever the destination, veterans emphasize that every detail matters, even the most obvious. "Nothing derails a shipment faster than a wrong address," says Thiers, who maintains a public database of herbaria addresses and contact information. "Sometimes they don't get returned for years, and unless you take extraordinary measures, you won't get them back." (With the volume of specimens that get mailed from the New York Botanic Garden—up to 30,000 a year—Thiers can't afford tracked shipments and uses cheaper library rate shipping.) Even the most diligent curators confess to late-night worries. "Any time you let something go out the door, there's a risk," says Solomon, who is continuing to send specimens to Australia. "The benefit from making the material available far outweighs the risk." Says Niezgoda: "Collections are meant to be used to promote scientific inquiry and this should not change."


News Article | May 9, 2017
Site: hosted2.ap.org

Scientists in South Africa reveal more on human-like species (AP) — A species belonging to the human family tree whose remnants were first discovered in a South African cave in 2013 lived several hundred thousand years ago, indicating that the creature was alive at the same time as early humans in Africa, scientists said Tuesday. A meticulous dating process showed that Homo naledi (nah-LEH-dee), which had a mix of human-like and more primitive characteristics such as a small brain, existed in a surprisingly recent period in paleontological terms, said Lee Berger of Wits University in Johannesburg. Berger led the team of researchers, which also announced that it had found a second cave with more fossils of the Homo naledi species, including a relatively well-preserved skull of an adult male. The conclusion that Homo naledi was living between 236,000 and 335,000 years ago — and had not become extinct much earlier — shows that the human "Homo" family tree was more diverse than previously thought at that point in the evolution of our species, Homo sapiens, said John Hawks of the University of Wisconsin-Madison and Wits University. The next step in research is to "sort the relationship of these different species to each other and also their role in our process of becoming human," Hawks said during an announcement of the discoveries at the Cradle of Humankind, a site near the South African town of Magaliesburg where the fossils were found. The research was also published in the journal eLife. The name of Homo naledi refers to the "Homo" evolutionary group, which includes modern people and our closest extinct relatives, and the word for "star" in the local Sotho language. The fossils were found in the Rising Star cave system, which includes more than 2 kilometers (1.25 miles) of underground, mapped passageways. The second chamber containing the more recent fossil discoveries is more than 100 meters (330 feet) from the cave where the original discoveries were made, and publicly announced in 2015. Some experts who were not involved in the research also marveled at the age of the fossils, determined by dating Homo naledi teeth and cave sediments. "This is astonishingly young for a species that still displays primitive characteristics found in fossils about 2 million years old, such as the small brain size, curved fingers, and form of the shoulder, trunk and hip joint. Yet the wrist, hands, legs and feet look more like those of Neanderthals and modern humans, and the teeth are relatively small and simple, and set in lightly built jawbones," Chris Stringer of the Natural History Museum in London wrote in an email to The Associated Press. Stringer said there were parallels with the late survival of the species Homo floresiensis — also known as the "hobbit" — in apparent isolation on an island in what is today Indonesia, and raised a key question: "How did a comparably strange and small-brained species linger on in southern Africa, seemingly alongside more 'advanced' humans?" Richard Potts of the Smithsonian Institution's National Museum of Natural History in Washington said it was likely that Homo naledi evolved and persisted in isolation from other species of Homo. '"Island habitats'" can occur on continents, too, in small environmental refuges that are sustained long term," Potts said. "Yes, on continents it's typically lizards, butterflies, fish, and small mammals that are susceptible to separation and isolated evolution, and the effects of that isolation can arise rapidly. To me, naledi and floresiensis are nature's experiments of isolated evolution in two of our evolutionary cousins." Berger, the research team leader, said the discovery of a second chamber with Homo naledi remains gives more credence to the idea that the species deliberately disposed of its dead in pitch-black caves that are extremely difficult to reach. However, some experts who were not on the research team questioned whether the small-brained species was capable of such behavior and speculated that other ways to access the chambers may have existed in the past. So far, there is no evidence that Homo naledi used stone tools or harnessed fire for its own uses. The new discoveries offer a unifying message that counters populism, intolerance and ethnic prejudice sweeping many parts of the world, said Adam Habib, vice-chancellor of Wits University. "This research shows that we come from common roots, that we represent a common humanity," Habib said. "If we're going to survive as a species, that's what we need to remember." Associated Press journalist Malcolm Ritter contributed to this report from New York.


News Article | May 9, 2017
Site: hosted2.ap.org

Scientists in South Africa reveal more on human-like species (AP) — A species belonging to the human family tree whose remnants were first discovered in a South African cave in 2013 lived several hundred thousand years ago, indicating that the creature was alive at the same time as early humans in Africa, scientists said Tuesday. A meticulous dating process showed that Homo naledi (nah-LEH-dee), which had a mix of human-like and more primitive characteristics such as a small brain, existed in a surprisingly recent period in paleontological terms, said Prof. Lee Berger of The University of the Witwatersrand in Johannesburg. Berger led the team of researchers, which also announced that it had found a second cave with more fossils of the Homo naledi species, including a relatively well-preserved skull of an adult male. The conclusion that Homo naledi was living between 236,000 and 335,000 years ago — and had not become extinct much earlier — shows that the human "Homo" family tree was more diverse than previously thought at that point in the evolution of our species, Homo sapiens, said John Hawks of the University of Wisconsin-Madison and Wits University. The next step in research is to "sort the relationship of these different species to each other and also their role in our process of becoming human," Hawks said during an announcement of the discoveries at the Cradle of Humankind, a site near the South African town of Magaliesburg where the fossils were found. The research was also published in the journal eLife. The name of Homo naledi refers to the "Homo" evolutionary group, which includes modern people and our closest extinct relatives, and the word for "star" in the local Sotho language. The fossils were found in the Rising Star cave system, which includes more than 2 kilometers (1.25 miles) of underground, mapped passageways. The second chamber containing the more recent fossil discoveries is more than 100 meters (330 feet) from the cave where the original discoveries were made, and publicly announced in 2015. Some experts who were not involved in the research also marveled at the age of the fossils, determined by dating Homo naledi teeth and cave sediments. "This is astonishingly young for a species that still displays primitive characteristics found in fossils about 2 million years old, such as the small brain size, curved fingers, and form of the shoulder, trunk and hip joint. Yet the wrist, hands, legs and feet look more like those of Neanderthals and modern humans, and the teeth are relatively small and simple, and set in lightly built jawbones," Chris Stringer of the Natural History Museum in London wrote in an email to The Associated Press. Stringer said there were parallels with the late survival of the species Homo floresiensis — also known as the "hobbit" — in apparent isolation on an island in what is today Indonesia, and raised a key question: "How did a comparably strange and small-brained species linger on in southern Africa, seemingly alongside more 'advanced' humans?" Richard Potts of the Smithsonian Institution's National Museum of Natural History in Washington said it was likely that Homo naledi evolved and persisted in isolation from other species of Homo. '"Island habitats'" can occur on continents, too, in small environmental refuges that are sustained long term," Potts said. "Yes, on continents it's typically lizards, butterflies, fish, and small mammals that are susceptible to separation and isolated evolution, and the effects of that isolation can arise rapidly. To me, naledi and floresiensis are nature's experiments of isolated evolution in two of our evolutionary cousins." Berger, the research team leader, said the discovery of a second chamber with Homo naledi remains gives more credence to the idea that the species deliberately disposed of its dead in pitch-black caves that are extremely difficult to reach. However, some experts who were not on the research team questioned whether the small-brained species was capable of such behavior and speculated that other ways to access the chambers may have existed in the past. So far, there is no evidence that Homo naledi used stone tools or harnessed fire for its own uses. The new discoveries offer a unifying message that counters populism, intolerance and ethnic prejudice sweeping many parts of the world, said Adam Habib, vice-chancellor of the University of the Witwatersrand. "This research shows that we come from common roots, that we represent a common humanity," Habib said. "If we're going to survive as a species, that's what we need to remember." Associated Press journalist Malcolm Ritter contributed to this report from New York.


Just as a high-profile expedition to retrieve fossils of human ancestors from deep within a cave system in South Africa was getting underway in 2013, two spelunkers pulled aside paleoanthropologist Lee Berger. They had found what looked like an ancient thigh bone in a completely different cave. “Can we go get it?” they asked. Berger was overseeing a team of 60 people, some of whom were 18 meters below ground gathering fossils. “This was day two. Lives were in danger. This was the beginning of my hair turning really white,” says Berger, of the University of the Witwatersrand in Johannesburg, South Africa. “I said ‘No, and don’t tell anyone. I don’t want anyone distracted.’” But on the last day of the expedition, which retrieved 1500 fossils of a mysterious new species of hominin named Homo naledi, Berger gave the spelunkers the go-ahead. They came back with the thigh bone plus photos of a skull poking out of the dirt in a second chamber of the cave system. “I couldn’t believe it,” Berger says. He and his team present the nearly complete new cranium plus 131 H. naledi fossils from the second cave in a series of papers in eLife this week. The new fossils reinforce a picture of a small-brained, small-bodied creature, which makes the dates reported in one paper all the more startling: 236,000 to 335,000 years ago. That means a creature reminiscent of much earlier human ancestors such as H. habilis lived at the same time as modern humans were emerging in Africa and Neandertals were evolving in Europe. “This is astonishingly young for a species that still displays primitive characteristics found in fossils about 2 million years old,” says paleoanthropologist Chris Stringer of the Natural History Museum in London. First announced in 2015, H. naledi was a puzzle from the start. Fossils from 15 individuals, including fragile parts of the face that are preserved in the new skull, show that the species combines primitive traits such as a small brain, flat midface, and curving fingers with more modern-looking features in its teeth, jaw, thumb, wrist, and foot. Berger’s team put it in our genus, Homo. But where it really fit in our family tree “hinged on the date,” says paleoanthropologist William Kimbel of Arizona State University in Tempe. Dating cave specimens is notoriously difficult because debris falling from cave walls or ceilings can mix with sediments around a fossil and skew the dates. And these fossils likely were moved over time by rising and falling groundwater, so identifying the sediments where they were originally buried is a challenge, says geologist Paul Dirks of James Cook University in Townsville, Australia. He enlisted 19 other scientists and several labs to independently test samples using several methods. They dated cave formations deposited atop the fossils using a technique called optically stimulated luminescence, which provided a minimum age of 236,000 years for the fossils. The radioactive decay of uranium in three teeth of H. naledi provided a maximum age of 335,000 years. Geochronologist Warren Sharp of the Berkeley Geochronology Center in California cautions that the maximum age may be off if the team didn’t accurately estimate how much uranium the teeth absorbed from groundwater over time. But Dirks points out that the results from several methods all point to fairly recent dates. “There is a little play in the upper limit, but it certainly isn’t going to shift to 1 million years,” he says. National Geographic leaked the dates in a brief Q&A with Berger in April, but without presenting the evidence. Now that he has seen the paper, geochemist Henry Schwarcz of McMaster University in Hamilton, Canada, calls the dating effort “an impressive tour de force.” The recent dates suggest that like the 60,000- to 100,000-year-old fossils of tiny H. floresiensis (the “Hobbit”) in Indonesia, H. naledi was a “twig off the mainstream of Homo—some little relic of a relatively archaic population,” Kimbel says. It was “a lineage that existed for 1 million years or more and we missed it,” says co-author John Hawks, a paleoanthropologist at the University of Wisconsin in Madison. Researchers remain skeptical, however, of some of Berger’s other claims, such as that H. naledi might have made Middle Stone Age tools found in the region. That would imply surprising sophistication in a small-brained hominin. “Yes, that hand could make and use tools,” says paleoanthropologist Bill Jungers of State University of New York in Stony Brook. But he agrees with paleoanthropologist Rick Potts of the National Museum of Natural History in Washington, D.C., who says the idea is a nonstarter because no tools, fire, or other signs of culture have been linked to the fossils. Ditto for the claim that H. naledi purposefully buried the bodies of its fellows in both caves, or that it might have acquired some of its modern traits by mating with other early members of Homo. “It’s just sheer speculation,” Kimbel says. Berger says the search for stone tools and other evidence to test whether H. naledi was capable of modern symbolic behavior is his top priority. “We’re going after all these critical questions—is there fire in there, is there DNA?” he says. His team began new forays into the caves last week.


News Article | May 22, 2017
Site: www.newscientist.com

The last common ancestor we shared with chimps seems to have lived in the eastern Mediterranean – not in East Africa as generally assumed. This bold conclusion comes from a study of Greek and Bulgarian fossils, suggesting that the most mysterious of all ancient European apes was actually a human ancestor, or hominin. However, other researchers remain unconvinced by the claim. Go back 12 or more million years ago and Europe was an ape’s paradise. But, about 10 million years ago, environmental conditions deteriorated and the European apes began to disappear. Apes became largely confined to Africa, splitting there into gorillas, chimpanzees and humans. At least, that’s what most researchers think happened. But in 2012, Nikolai Spassov at the National Museum of Natural History in Sofia, Bulgaria, and his colleagues reported the discovery of an ape tooth from Bulgaria that was just 7 million years old. It was, they said, the youngest European ape fossil yet found. Spassov and his colleagues – including Madelaine Böhme at the University of Tübingen in Germany and David Begun at the University of Toronto, Canada – now think the tooth belongs to an ape called Graecopithecus that clung on in eastern Europe long after the other apes had disappeared from the continent. What’s more, the team says, Graecopithecus was no ordinary ape – it was a hominin. Other than the Bulgarian tooth, Graecopithecus is known from just one fossil jawbone found near Athens in 1944. The fossil was reportedly unearthed as the occupying German forces were building a wartime bunker – although Spassov says the exact details of the story are unclear. With so little fossil material to work with, Graecopithecus is the most poorly known of all European apes. This is not helped by the fact that the Greek jawbone – nicknamed El Graeco – has a heavily worn surface. But Spassov and his colleagues have used a micro-CT scanner to peer into the jawbone of El Graeco, and found that the roots of one of the premolars are “fused” together in an unusual way. “This condition is so far only known to occur regularly in hominins – pre-humans and humans,” Spassov says. “It is extremely rare in recent chimps.” There are also hints from the jaw that Graecopithecus had relatively small canines – another hominin trait. Together, the two features suggest Graecopithecus may have been a hominin, the researchers say. In a complementary analysis, the team has also investigated the local geology in Greece and Bulgaria at the time to establish that Graecopithecus lived in exactly the sort of dry savannah-like environment traditionally thought to have driven early hominin evolution. What’s more, geological dating techniques suggest it was alive between 7.18 and 7.25 million years ago – which means Graecopithecus slightly predates the oldest potential hominin found in Africa: Sahelanthropus is between 7 and 6 million years old. Putting the pieces of the puzzle together, the team thinks that hominins might have split from the chimp evolutionary lineage in the eastern Mediterranean a little earlier than 7.25 million years ago. In other words, they say, that our last common ancestor with chimps may have been an eastern European. David Alba at the Catalan Institute of Palaeontology in Barcelona, Spain says there is value to the new work: it provides convincing anatomical evidence that Graecopithecus is different from any other ancient ape found in Europe – something that wasn’t clear from earlier studies of the jawbone. But he is less convinced by the idea that the tooth roots alone can confirm that Graecopithecus is a hominin. He says study co-author David Begun has been arguing for 20 years that the great apes first appeared in Europe. “It is not surprising at all that Begun is now arguing that hominins as well originated in Europe.” Bernard Wood at George Washington University in Washington DC says the “hominin teeth” claim is relatively weak. “This would not be a character I would want to hang my hat on,” he says. Sergio Almécija, also at George Washington University, says it is important to bear in mind that primates seem particularly prone to evolving similar features independently. “Single characters are not reliable to make big evolutionary [claims].” Others are even more blunt. Tim White at the University of California, Berkeley, says the new research “tries to resurrect Begun’s tired argument with a long-known crappy fossil, newly scanned”. However, Begun rejects these criticisms. “The fact is that if this specimen had been found in Africa at this age there would be much less scepticism,” he says. The new evidence does, potentially, cast the earliest potential hominins from Africa in a new light, says John Hawks at the University of Wisconsin-Madison. He says that dental similarities have been some of the most prominent features used to argue that genera like Sahelanthropus and Ardipithecus are hominins. Finding similar dental features in a European ape suggests the features might not be indicative of hominins after all. “We need to look again at those supposed early hominins, which really share very few features with us,” says Hawks. “I think we should consider that they might instead be part of a diversity of apes that are continuous across parts of Africa and Europe, and our real ancestry may still be undiscovered.” Some solid science in the new studies risks being lost in a broader argument over whether or not Graecopithecus is a hominin, says Nathan Young at the University of California in San Francisco. “The paper falls into a typical pattern in which a Miocene ape is not appreciated for its own characteristics and evolution, but instead is placed in the context of hominin evolution,” he says. Ultimately, however, the early human fossil record is so poorly known that it’s impossible to definitively dismiss the new claims, says Alba. “Of course, it is possible that hominins first evolved in Europe – however, evidence favouring this view is anecdotal at best,” he says. Likewise, Graecopithecus might be a hominin, he says, but that can only be confirmed if more fossils are found. Spassov is optimistic about the likelihood of those remains coming to light. “There are chances of finding more fossils,” he says. “We are working on that.” Read more: Key moments in human evolution happened far from our Africa home


Grant
Agency: European Commission | Branch: H2020 | Program: CSA | Phase: MSCA-NIGHT-2016 | Award Amount: 171.75K | Year: 2016

FRESH (Find Research Everywhere and SHare) is led by the Center for Research and Analysis with 13 partners and 5 associated partners. The Consortium includes Bulgarias first technological park, a chamber of industry and commerce, a pan-European organisation, leading research organisations, academia, and media. The aim is to create a series of participatory and media events to promote research careers, aimed in particular towards young people and their parents. Building on existing understanding developed through previous local initiatives including Researchers Night, and with reference to Europe-wide research like the Special Eurobarometer 401, as well as the MASIS report and the in-depth Education and Training Monitor 2015 for Bulgaria , the focus of this 20-month programme will be on enhancing the public understanding of and engagement with science. Core activities during the Night will include a digital participatory campaign to engage audiences across the country; international live streaming; science city quests and quizzes; science cafes; hands-on experiments; science shows; simulations; games and competitions. Thematic programmes will include, among other, food and nutrition, inspired by 2016 International Year of Pulses , engineering, oceanology, innovation and business incubators, technological transfer, medicine, and others. The on-the-ground activities will take place in the largest cities including several where Researchers Night has not been marked. Innovation will be an intricate part of the events through the use of online technology to enhance the physical activity, engage particularly young audiences and to guarantee sustainability outside the lifespan of the project. The activities of the first year will allow learning to accrue from a thorough evaluation. The project will strengthen the capabilities of the partners in organising events for a general audience, and for underserved audiences, including girls and people with hearing disabilities.


Temkin I.,National Museum of Natural History
BMC Evolutionary Biology | Year: 2010

Background. The superfamily Pterioidea is a morphologically and ecologically diverse lineage of epifaunal marine bivalves distributed throughout the tropical and subtropical continental shelf regions. This group includes commercially important pearl culture species and model organisms used for medical studies of biomineralization. Recent morphological treatment of selected pterioideans and molecular phylogenetic analyses of higher-level relationships in Bivalvia have challenged the traditional view that pterioidean families are monophyletic. This issue is examined here in light of molecular data sets composed of DNA sequences for nuclear and mitochondrial loci, and a published character data set of anatomical and shell morphological characters. Results. The present study is the first comprehensive species-level analysis of the Pterioidea to produce a well-resolved, robust phylogenetic hypothesis for nearly all extant taxa. The data were analyzed for potential biases due to taxon and character sampling, and idiosyncracies of different molecular evolutionary processes. The congruence and contribution of different partitions were quantified, and the sensitivity of clade stability to alignment parameters was explored. Conclusions. Four primary conclusions were reached: (1) the results strongly supported the monophyly of the Pterioidea; (2) none of the previously defined families (except for the monotypic Pulvinitidae) were monophyletic; (3) the arrangement of the genera was novel and unanticipated, however strongly supported and robust to changes in alignment parameters; and (4) optimizing key morphological characters onto topologies derived from the analysis of molecular data revealed many instances of homoplasy and uncovered synapomorphies for major nodes. Additionally, a complete species-level sampling of the genus Pinctada provided further insights into the on-going controversy regarding the taxonomic identity of major pearl culture species. © 2010 Tmkin; licensee BioMed Central Ltd.


Wagner P.J.,National Museum of Natural History | Estabrook G.F.,University of Michigan
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014

Evolution provides many cases of apparent shifts in diversification associated with particular anatomical traits. Three general models connect these patterns to anatomical evolution: (i) elevated net extinction of taxa bearing particular traits, (ii) elevated net speciation of taxa bearing particular traits, and (iii) elevated evolvability expanding the range of anatomies available to some species. Traitbased diversification shifts predict elevated hierarchical stratigraphic compatibility (i.e., primitive→derived→highly derived sequences) among pairs of anatomical characters. The three specific models further predict (i) early loss of diversity for taxa retaining primitive conditions (elevated net extinction), (ii) increased diversification among later members of a clade (elevated net speciation), and (iii) increased disparity among later members in a clade (elevated evolvability). Analyses of 319 anatomical and stratigraphic datasets for fossil species and genera show that hierarchical stratigraphic compatibility exceeds the expectations of trait-independent diversification in the vast majority of cases, which was expected if traitdependent diversification shifts are common. Excess hierarchical stratigraphic compatibility correlates with early loss of diversity for groups retaining primitive conditions rather than delayed bursts of diversity or disparity across entire clades. Cambrian clades (predominantly trilobites) alone fit null expectations well. However, it is not clearwhether evolution was unusual among Cambrian taxa or only early trilobites. At least among post-Cambrian taxa, these results implicate models, such as competition and extinction selectivity/resistance, as major drivers of trait-based diversification shifts at the species and genus levels while contradicting the predictions of elevated net speciation and elevated evolvability models.


Lavelle C.,National Museum of Natural History | Lavelle C.,French National Center for Scientific Research | Lavelle C.,French Institute of Health and Medical Research
Current Opinion in Genetics and Development | Year: 2014

Molecular motors such as polymerases produce physical constraints on DNA and chromatin. Recent techniques, in particular single-molecule micromanipulation, provide estimation of the forces and torques at stake. These biophysical approaches have improved our understanding of chromatin behaviour under physiological physical constraints and should, in conjunction with genome wide and in vivo studies, help to build more realistic mechanistic models of transcription in the context of chromatin. Here, we wish to provide a brief overview of our current knowledge in the field, and emphasize at the same time the importance of DNA supercoiling as a major parameter in gene regulation. © 2014 Elsevier Ltd.


Grant
Agency: European Commission | Branch: FP7 | Program: MC-IRSES | Phase: FP7-PEOPLE-2009-IRSES | Award Amount: 478.80K | Year: 2011

The project is finalized to establish long-term research co-operations through a coordinated joint program of research staff exchanges for short periods on the following topics: selection of plant species according to ethnobotanical and ethnopharmacological approaches; breeding to preserve biodiversity and gene reservation of food, medicinal and aromatic plants; cultivation of food, medicinal and aromatic plant species to improve the quality of the starting material for industrial use (using good agrotechnological guidelines); biotechnological protocols for the production of standardized plant material or for the maintainance of plant species; identification of rural areas which have to be examined as mapped sites and official knowledge degree of the nutraceuticals field; extraction, isolation and structural elucidation of secondary metabolites from plants in order to evaluate biological properties of plant extracts and their bioactive constituents as nutraceutical ingredients with innovative techniques and facilities; development of extraction and quali-quantitative evaluation of plant constituents with medicinal, food, agronomic and industrial interest (bioactive compounds, essential oils, natural aroma, flavour, fragrances, natural dyes); chemical profile of essential oils and volatile fractions for the selection of essential oil from different plant families; development and validation of bio-analytical methods devoted to biomarkers and active compounds in plant extracts; evaluation of antibacterial, antioxidant, cytotoxic, genotoxic, mutagen and antimutagen, apoptotic activity of plant extracts and derivatives; structure-activity relationship studies on standardized extracts or new bioactive compounds isolated from the selected plant material; Emi- or total synthesis of novel products from natural products identified as molecular target to development new drugs.

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