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Categories: Ecology: Research, Paleontology: Fossils

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Hispaniola once had among the highest diversity of rodents in the Caribbean. Today, only one rodent species remains, and its prospects for survival are uncertain. New carbon dates place the blame squarely on humans.

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Climate change will reshape ecosystems through two types of events: short-term, extreme events -- or 'pulses' -- and long-term changes, or 'presses.' Understanding the effects of presses and pulses is essential as conservationists and policymakers try to preserve ecosystems and safeguard biodiversity. Researchers have discovered how different presses and pulses impacted Magellanic penguins -- a migratory marine predator -- over nearly four decades and found that, though individual presses and pulses impacted penguins in a variety of ways, both were equally important for the future survival of the penguin population. They also found that these types of climate changes, taken together, are leading to an overall population decline at their historically largest breeding site.

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Save the ... parasites? Analyzing 140 years of parasite abundance in fish shows dramatic declines, especially in parasites that rely on three or more host species. The decline is linked to warming ocean temperatures. Parasitic species might be in real danger, researchers warn -- and that means not just fewer worms, but losses for the entire ecosystem.

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Smallpox was once one of humanity's most devastating diseases, but its origin is shrouded in mystery. For years, scientific estimates of when the smallpox virus first emerged have been at odds with historical records. Now, a new study reveals that the virus dates back 2,000 years further than scientists have previously shown, verifying historical sources and confirming for the first time that the disease has plagued human societies since ancient times.

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Using a new method based upon comparing DNA mutation rates between parents and offspring, evolutionary biologists have revealed the average age of mothers versus fathers over the past 250,000 years, including the discovery that the age gap is shrinking, with women's average age at conception increasing from 23.2 years to 26.4 years, on average, in the past 5,000 years.

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Researchers suggest that rising levels of humanmade chemicals, accumulating in marine plankton, might be used to monitor the impact of human activity on ecosystem health and perhaps study links between ocean pollution and land-based rates of childhood and adult chronic illnesses.

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This study, conducted from 2015-19 in the Thunder Basin National Grassland, may be the first to specifically examine the multispecies impacts of a wide-scale plague outbreak, which reduced the area covered by prairie dog colonies from nearly 25,000 acres to only about 125 acres in the study area. The 2017 outbreak was followed by abnormally high precipitation in 2018, which caused vegetation to grow quickly and taller without the presence of prairie dogs. The researchers found that the mountain plover, birds that thrive when vegetation is kept shorter by prairie dogs, almost disappeared from the study area, while migrant songbirds such as the lark bunting, which prefer taller vegetation, increased in number. Meanwhile, species including ferruginous hawks, badgers and swift foxes declined dramatically as their prey base crashed.

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Scientists have discovered for the first time that invasive rats on tropical islands are affecting the territorial behavior of fish on surrounding coral reefs. The new study shows that the presence of invasive black rats on tropical islands is causing changes in the territorial behavior of the jewel damselfish -- a herbivorous species of tropical reef fish that 'farm' algae in the branches of corals.

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Researchers have revealed the effects of high pathogenicity avian influenza virus infection on an Ezo red fox and a Japanese raccoon dog, linking their infection to a recorded die-off of crows.

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Existing conservation efforts are insufficient to protect Antarctic ecosystems, and population declines are likely for 65% of the continent's plants and wildlife by the year 2100, according to a new study.

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Ocean warming is driving an increase in the frequency and severity of marine heatwaves, causing untold damage to coral reefs. Tropical corals, which live in symbiosis with tiny single celled algae, are sensitive to high temperatures, and exhibit a stress response called bleaching when the ocean gets too hot. In the last 4 decades, marine heatwaves have caused widespread bleaching, and killed millions of corals. Because of this, a global search is underway for reefs that can withstand the heat stress, survive future warming, and act as sources of heat-tolerant coral larvae to replenish affected areas both naturally and through restoration.

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Microraptor was an opportunistic predator, feeding on fish, birds, lizards -- and now small mammals. The discovery of a rare fossil reveals the creature was a generalist carnivore in the ancient ecosystem of dinosaurs.

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Europasaurus is a long-necked, herbivorous dinosaur that lived in the Late Jurassic, about 154 million years ago, on a small island in modern-day Germany. Recently, scientists examined fossil braincase material of Europasaurus with the aid of micro-computed tomography (micro-CT). The digital reconstruction of the inner ear of Europasaurus gave the researchers new insights not only into its hearing ability, but also into its reproductive and social behavior.

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Scientists have discovered that the atmosphere contained far less CO2 than previously thought when forests emerged on our planet, the new study has important implications for understanding how land plants affect the climate.

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An international research team examines a rich fossil bed in the renowned Berlin-Ichthyosaur State Park in Nevada's Humboldt-Toiyabe National Forest, where many 50-foot-long ichthyosaurs (Shonisaurus popularis) lay petrified in stone. The study offers a plausible explanation as to how at least 37 of these marine reptiles came to meet their ends in the same locality -- a question that has vexed paleontologists for more than half a century. The research presents evidence that these ichthyosaurs died at the site in large numbers because they were migrating to this area to give birth for many generations across hundreds of thousands of years.

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Fossilized microbial skins can give us a glimpse of how the climate was in the deep geological past. By discovering the 'missing link' between such fossil skins and the skins of living bacteria, researchers have greatly improved the accuracy of climate reconstructions and predictions.

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Discoveries at a major new fossil site in Morocco suggest giant arthropods -- relatives of modern creatures including shrimps, insects and spiders -- dominated the seas 470 million years ago.

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Analysis of teeth of extinct lemurs has revealed fascinating clues to the evolution of humans, a new study has found.

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While the Diprotodon -- the extinct megafauna species that is distantly related to wombats but was the size of a small car -- is commonly (but incorrectly) thought of as Australia's 'giant wombat', researchers have shed light on a large species that does belong in the modern-day wombat family. The complete skull of this true fossil giant wombat, found in a Rockhampton cave in Queensland, Australia and estimated to be around 80,000 years old, has been described for the first time.

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Modern Papuans' immune system likely evolved with a little help from the Denisovans, a mysterious human ancestor who interbred with ancient humans, according to a new study.