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Categories: Geoscience: Geography, Paleontology: Fossils

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Birds across the Americas are getting smaller and longer-winged as the world warms, and the smallest-bodied species are changing the fastest.

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A new study provides the first observational evidence of the stabilization of the anti-cyclonic Beaufort Gyre, which is the dominant circulation of the Canada Basin and the largest freshwater reservoir in the Arctic Ocean.

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Scientists have used sub-surface imaging and aerial surveys to see through floodplains in the Red Lily Lagoon area of West Arnhem Land in Australia. These ground-breaking methods showed how this important landscape in the Northern Territory was altered as sea levels rose about 8,000 years ago.

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New research begins to unravel the role dust plays in nourishing global ocean ecosystems while helping regulate atmospheric carbon dioxide levels.

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For decades, scientists have used the amount of seaweed at the ocean's surface as a proxy for the health of coral reefs below. However, a new global study of more than 1,200 marine locations over a 16-year period reveals that this approach has been misleading -- and may even have hidden signs of reef stress.

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With glaciers melting at unprecedented rates due to climate change, invertebrates that live in the cold meltwater rivers of the European Alps will face widespread habitat loss, warn researchers. Many of the species are likely to become restricted to cold habitats that will only persist higher in the mountains, and these areas are also likely to see pressures from the skiing and tourism industries or from the development of hydroelectric plants.

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An international research team has for the first time successfully isolated ancient human DNA from a Paleolithic artefact: a pierced deer tooth discovered in Denisova Cave in southern Siberia. To preserve the integrity of the artefact, they developed a new, nondestructive method for isolating DNA from ancient bones and teeth. From the DNA retrieved they were able to reconstruct a precise genetic profile of the woman who used or wore the pendant, as well as of the deer from which the tooth was taken. Genetic dates obtained for the DNA from both the woman and the deer show that the pendant was made between 19,000 and 25,000 years ago. The tooth remains fully intact after analysis, providing testimony to a new era in ancient DNA research, in which it may become possible to directly identify the users of ornaments and tools produced in the deep past.

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Traces of sex hormones extracted from a woolly mammoth's tusk provide the first direct evidence that adult males experienced musth, a testosterone-driven episode of heightened aggression against rival males, according to a new study.

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In the face of global warming and other environmental changes, corals in the Atlantic Ocean have declined precipitously in recent years, while corals in the Pacific and Indian Oceans are faring better. By describing several species of symbiotic algae that these corals need to grow, an international team has found that these mutualistic relationships from the Indo-Pacific may be more flexible and ultimately resilient to higher ocean temperatures than those in the Atlantic.

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A recent study found that many of the fossils from Germany's Posidonia shale do not get their gleam from pyrite, commonly known as fool's gold, which was long thought to be the source of the shine. Instead, the golden hue is from a mix of minerals that hints at the conditions in which the fossils formed. The discovery is important for understanding how the fossils -- which are among the world's best-preserved specimens of sea life from the Early Jurassic -- came to form in the first place, and the role that oxygen in the environment had in their formation.

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According to researchers, a new analysis of an 80-million-year-old permineralized pollen cone found in the Campanian Holz Shale formation located in Silverado Canyon, California, offers a more accurate cycad natural history -- one where the plants diversified during the Cretaceous.

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Greenlandic ice is teeming with life, both on the surface and underneath. There are microscopic organisms that until recently science had no idea existed. There is even evidence to suggest that the tiny creatures color the ice and make it melt faster.

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The West Antarctic Ice Sheet is melting rapidly, raising concerns it could cross a tipping point of irreversible retreat in the next few decades if global temperatures rise 1.5 to 2.0 degrees Celsius (2.7 to 3.8 degrees Fahrenheit) above preindustrial levels. New research finds that 6,000 years ago, the grounded edge of the ice sheet may have been as far as 250 kilometers (160 miles) inland from its current location, suggesting the ice retreated deep into the continent after the end of the last ice age and re-advanced before modern retreat began.

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New research pushes back the oldest evidence of C4 grass-dominated habitats in Africa -- and globally -- by more than 10 million years, with important implications for primate evolution and the origins of tropical C4 grasslands and savanna ecosystems across the African continent and around the world.

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As the Arctic warms and loses sea ice, trans-Arctic shipping has increased, reducing travel time and costs for international trade. However, a new study finds that the Arctic Ocean is getting foggier as ice disappears, reducing visibility and causing costly delays as ships slow to avoid hitting dangerous sea ice.

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California sea lions have managed to maintain -- and, in the case of males, increase -- their average body size as their population grows and competition for food becomes fiercer. This is in contrast to other marine mammals, whose average body size tends to decrease as their numbers increase. Researchers report that sexual selection was a strong driving force for males to grow bigger and to strengthen muscles in their neck and jaw that help them fight for mates. Both male and female sea lions evaded food shortages by diversifying their diets and, in some cases, foraging further from the shore.

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Life in the ocean's 'twilight zone' could decline dramatically due to climate change, new research suggests.

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A major collaboration involving 80 scientists from Europe and South America has identified the regions of the Amazon rainforest where trees are most likely to face the greatest risk from drier conditions brought about by climate change. Based on the analysis, the scientists predict trees in the western and southern Amazon face the greatest risk of dying. They also warn that previous scientific investigations may have underestimated the impact of drought on the rainforest because those studies focused on the central-eastern part of the forest, which is the least vulnerable to drought.

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Researchers have identified a previously unknown group of bacteria, called UBA868, as key players in the energy cycle of the deep ocean. They are significantly involved in the biogeochemical cycle in the marine layer between 200 and 1000 meters.

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Genetic analysis links 3,000-year-old bone found in cave to modern Alaska Natives.