In a big step forward for cloning research, scientists have produced healthy clones of mice that were dead and frozen for 16 years. Researchers say the new technique could allow conservationists to freeze tissue from endangered species, which could then be used to produce clones if those species become extinct. The finding also raises hopes of one day being able to resurrect extinct animals frozen in permafrost, such as the woolly mammoth, says [lead researcher] Teruhiko Wakayama…. “It would be very difficult, but our work suggests that it is no longer science fiction,” he says [New Scientist].
Researchers have previously produced clones from frozen animal tissue, but only from specimens that were preserved with special chemicals to protect cells from damage during the deep freeze. In this study, published in the Proceedings of the National Academy of Sciences [subscription required], no such special precautions were taken when the mice were stowed in a freezer 16 years ago. Many zoos are not in a position to collect cells and freeze them in such a way as to preserve their viability, says [cloning expert] Robert Lanza … but they can put a dead animal “in a plastic bag and throw it in the freezer”, he adds. “With a kitchen freezer you could store the genetic diversity of every panda in existence” [New Scientist].
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Several rare varieties of staghorn coral have begun mating across species lines and are creating surprisingly robust hybrids, according to a new study; researchers believe the unusual step is an effort to adapt to changing ocean conditions and avoid extinction. The findings are an unexpected piece of promising news about coral reefs, which usually make the headlines for their potential fate as one of the first victims of global warming.
Coral reefs around the world are under pressure from pollution and gradually warming oceans, and researchers have worried that rare species are particularly vulnerable to extinction. But in the case of these staghorns, the new study shows that when faced with a shortage of mates of their own kind, these rare corals have cast a wider net and started cross-breeding with other coral species, producing hybrids. “It pushes the boundaries of our traditional understanding of species,” said a researcher, Zoe Richards. “They are being a little promiscuous” [Sydney Morning-Herald].
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Global warming isn’t just a threat to polar bears in the rapidly warming Arctic, a new study says: Species in the tropics are beginning to feel the effects as well, and it will only get worse. Researchers surveyed more than 1,900 species of plants, insects, and fungi in a Costa Rica rainforest and came to the troubling conclusion that if world temperatures continue to rise as predicted over the next 50 years, half of those species will have to move to completely new territory to find an appropriate habitat.
The situation is complicated for tropical species, says lead researcher Robert Colwell; shifting north or south doesn’t bring significantly lower temperatures, so species will have to take up residence at higher altitudes to survive. In the absence of mountainsides to serve as a cool refuge, those plants and insects that cannot face higher temperatures may disappear as it would require migrations of hundreds or even thousands of miles to find a suitable cooler climate—crossing habitats utterly changed by human impacts. “For lowland tropical species whose geographical range lies far from mountains, for example in the middle of the Amazon,” Colwell says, “the prospect for extinction cannot be dismissed” [Scientific American].
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An international group of researchers has issued a dire warning about the state of the world’s wild animals. A new report from the International Union for the Conservation of Nature (IUCN) lists one in four land mammals as endangered, as well as one in three marine mammals. Life on Earth is disappearing fast with man inflicting most of the damage…. On land more species face oblivion because of loss of habitat, hunting and climate change while in the oceans pollution and the side effects of fishing are taking a huge toll [Telegraph].
The new assessment — which took 1,700 experts in 130 countries a total of five years to complete — paints “a bleak picture,” leaders of the project wrote in a paper being published in the journal Science. The overview … covers all 5,487 wild species identified since 1500. It is the most thorough tally of land and marine mammals since 1996 [Washington Post].
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Researchers may be able to recreate a species of giant tortoise that went extinct from the Galapagos Islands with a program of careful breeding. The new possibility hinges on the discovery that a species of giant tortoise living on the biggest island, Isabela, is very similar genetically to the extinct species, Geochelone elephantopus, which vanished from the island Floreana over a hundred years ago.
By mating Isabela tortoises that are most genetically similar to G. elephantopus, selecting the offspring that are most similar and mating those, through successive generations the species’ genetic makeup may be largely restored [The New York Times]. Says lead researcher Gisella Caccone: “We might need three or four generations to do this…. But in theory it could be done, and I think it’s pretty exciting to bring back from the dead a genome that we thought was gone” [BBC News].
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The dinosaurs that held dominion over the Earth in the Jurassic Period didn’t rule the lands because they out-competed every rival, a new study says. Researchers studied fossil evidence from an earlier epoch, the Triassic Period, and say that dinosaurs showed no evidence of being better adapted to their environment than their challengers. “For a long time it was thought that there was something special about the dinosaurs that helped them become more successful during the Triassic, the first 30 million years of their history, but this isn’t true,” said lead author of the study, Steve Brusatte [LiveScience].
Instead they may have just been lucky enough to survive a drastic climate shift when their rivals didn’t. Researchers compared fossils from the 30 million years in the Triassic when dinosaurs coexisted with crurotarsan archosaurs, a group whose only living relative is crocodiles. They found that not only did the groups evolve at the same rate, but the crurotarsans even developed a wider range of body types than dinosaurs, suggesting that the group as a whole was more successful at developing to live in different habitats and ecosystems [Telegraph].
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The last woolly mammoths, who tromped around the Siberian tundra before going extinct about 10,000 years ago, had North American roots, according to a new genetic analysis. Scientists studied DNA from the remains of 160 mammoths from across North America and Eurasia, and determined that the last remaining mammoths were migrants who had come to Siberia via the Bering land bridge, and somehow replaced the endemic population.
Researchers believe that mammoths originally spread from Asia to North America via the land bridge, creating two genetically distinct populations. Now, they’re hypothesizing that some members of the North American group eventually made a return trip and proved hardier survivors than the Siberian group. “For some reason the North American guys went back over and became kings,” says [lead researcher] Hendrik Poinar [New Scientist].
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Dinosaurs—they grow up so fast, especially if they’re trying not to get eaten.
Hypacrosaurus, a duck-billed dinosaur that could reach more than 30 feet in length, was a preferred meal of the Tyrannosaurus Rex. But this prey dinosaur had a trick to keep the species alive—Hypacrosaurus grew to adulthood remarkably quickly, according to a new study in the Proceedings of the Royal Society B [pdf]. The research suggests that it took 10 to 12 years for Hypacrosaurus to become fully grown. Tyrannosaurs, however, reached adulthood after 20 to 30 years, said Drew Lee, a postdoctoral fellow in Ohio University’s College of Osteopathic Medicine who co-authored the paper [Science Daily].
The Hypacrosaurus’ accelerated growth rate allowed it to reach sexual maturity at only two or three years old, giving it the chance to reproduce before predators gobbled it up, according to study co-author Lisa Noelle Cooper. “That’s another added bonus when facing predators—if you can keep reproducing, you’re set, it’s the stuff of evolution,” said Cooper [AFP].
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An ambitious study of all the primates on planet Earth has found that almost half of all species are threatened by extinction because of habitat loss and poaching. The latest Red List of Threatened Species, drawn up by the International Union for Conservation of Nature (IUCN), says that almost 50 per cent of the world’s 634 types of primate may disappear forever [Telegraph].
The findings highlight the multiplying threats facing primates throughout Africa, Asia, and South America, says IUCN official Russell Mittermeier: “Tropical forest destruction has always been the main cause, but now it appears that hunting is just as serious a threat in some areas, even where the habitat is still quite intact. In many places, primates are quite literally being eaten to extinction” [Bloomberg]. The study results were announced at the current International Primatological Society meeting.
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An extinct ancestor of the great white shark had a powerful bite that wouldn’t just put Jaws to shame, according to a new fossil analysis by Australian researchers. The colossal force of Carcharodon megalodon – also known as Big Tooth – made even Tyrannosaurus rex look puny [Telegraph].
In the study, to be published in an upcoming issue of the Journal of Zoology [subscription required], researchers took CT scans of both the skulls of great white sharks and those of the prehistoric megalodon, who swam the oceans about a million and a half years ago. They made computer models of the skulls, and then ran an analysis on the models that engineers use to determine how machinery holds up under stress.
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The Cretaceous period was such a good time for evolution that researchers talk about the “Cretaceous Terrestrial Revolution,” when as an explosion of new plant and animal species appeared. But researchers say that a detailed analysis of dinosaur diversity during this period debunks the prevailing theory that dinosaurs took part in this evolutionary spree; instead, their rapid evolution had taken place millions of years before.
The Cretaceous period, which lasted from 145 million years ago to 65 million years ago… saw the diversification of pollinating insects such as bees, butterflies, and moths. New forms of lizards, crocodiles, and snakes appeared, as did many of the ancestors of modern groups of birds and mammals. The Cretaceous also saw the explosion of angiosperms, or flowering plants [ScienceNOW Daily News]. Some researchers have previously suggested that the wide availability of those flowering plants sparked an evolutionary surge in dinosaurs who fed on the plants, and others who fed on the plant-eaters.
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A federal judge declared that California’s water management system is jeopardizing the existence of the state’s salmon and steelhead, which have to navigate the complicated network on their journeys out to the ocean and back to their riverine spawning grounds. The judge’s ruling established that the canals and pumps that deliver water to 23 million Californians are causing “irreparable harm” to two salmon species, as well as the threatened Central Valley steelhead [AP].
The judge stopped short of ordering immediate remedies like storing more water behind Shasta Dam, which could be released later to help migrating fish. But the judge’s conclusions mean regulators will be forced to impose more protective conditions when they issue a new permit in March, lawyers said. “It’s a clear signal that business as usual in the Delta is not going to be acceptable,” said Kate Poole, a lawyer for the Natural Resources Defense Council [Contra Costa Times].
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Researchers have already noted that global warming is causing some species to shift their habitats, like mountain animals that are moving to higher latitudes to find the cooler temperatures that they’re adapted for. But now some conservationists say it’s time to consider relocating species that are threatened with extinction due to their rapidly changing habitats. It’s a process called “assisted colonization.”
Some researchers say that as the extinction rate zooms upwards, humans will have no choice but to step in to save some animals. “It’s a showdown. The impacts of climate change on animals have become apparent. And it’s time to decide whether we’re going to do something,” said ecologist Jessica Hellmann…. “Reducing CO2 is vital, but we might have to step in and intervene” [Wired News].
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About 93 million years ago, a burst of volcanic activity on the ocean floor led to a massive extinction event that killed one-tenth of the world’s marine invertebrates, according to a new study. The Caribbean region was the likely source of the sea-floor eruptions, says [study coauthor Steven] Turgeon. He says massive amounts of lava would have burbled and blasted up from inside the earth, setting off a “chain reaction” that took thousands of years to play out [Canwest News Service].
[T]he volcanoes spewed out metal-rich fluids that seeded the upper level of the ocean with micronutrients…. Tiny life forms on the sea surface, called phytoplankton, gorged on the food, and storing up carbon as they grew. They then sank to the sea floor and decayed, stripping the ocean of oxygen [BBC News] in a large-scale example of the phenomenon that causes the annual “dead zone” in the Gulf of Mexico. The oxygen-starved waters were a poor environment for marine life, and creatures from giant clams to tiny invertebrates went extinct.
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Australia’s Tasmanian devils are breeding at younger ages in response to a strange form of infectious cancer that is spreading rapidly through devil populations. The feisty marsupials are now reproducing before the lethal cancer strikes them down—a response that may be the species’ only chance to avoid extinction.
Researcher Shelly Lachish explains: “In a normal, healthy devil population the females would rarely breed before the age of two, but now 60 per cent of one-year-olds in diseased populations have produced young…. They are teenagers in human terms. It’s a remarkable change given early breeding was once very, very rare” [Sydney Morning Herald]. While some researchers believe this to be an example of rapid evolution, skeptics say the case is not yet closed.
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