Miller said the question remains what impact, if any, humans had on the global decline and extinction of mammoths. "This happens in the vertebrate record as well." When you see shells on the beach, some could be from animals that died recently while others might be from shellfish that died millennia ago," Simpson said. "Seashells can sit on the seafloor for thousands of years. Simpson said his work studying marine environments from recently eroded hillsides demonstrates how difficult it is to date ancient specimens. But the most recent mammoth fossils found in the Siberian area were entombed in permafrost 11,000 years ago. In some remote parts of the Arctic, it's not unusual to find 2,000-year-old caribou antlers on the surface, Miller said. The paper notes that the mummified remains of elephant seals near Antarctica can be more than 5,000 years old. The researchers say the slow decomposition of animals in Arctic regions could explain how mammoth DNA is showing up thousands of years later than the most recent mammoth fossil discovered. In the Arctic and other cold-weather places, it can take thousands of years for something to decompose." In places where decomposition is slow, that means long-dead and even long-extinct species can continue to make their way into surrounding sediments. "In fact, DNA continues to be shed long after the animal dies. "DNA is shed from organisms all the time," Miller said. Miller said researchers can't tell whether environmental DNA preserved in sediment was shed from a living or dead animal. But currently we can't independently date DNA found in sediments," Miller said.įrom recent discoveries like the baby mammoth found in Canada this year, we know that many ice age animals that died tens of thousands of years ago can become mummified in the Arctic's dry, cold environment. "We can radiocarbon date all kinds of things: bones, teeth, charcoal, leaves. But not everything can be dated, Miller said. Researchers have many tools to date sedimentary deposits and the materials contained in them. Materials of different ages are routinely buried together." "The issue is you have no idea how old that DNA is," Miller said. An international team of researchers examined environmental DNA of mammoth remains and more than 1,500 Arctic plants to conclude that a wetter climate quickly changed the landscape from tundra grassland steppe to forested wetlands that could not support many of these big grazing animals, driving mammoths to extinction as recently as 3,900 years ago.īut in a rebuttal paper in Nature, UC College of Arts and Sciences assistant professor Joshua Miller and co-author Carl Simpson at the University of Colorado Boulder argue that the environmental DNA used to establish their updated timeline is more complex than previously recognized. So it's only natural to wonder if humans contributed to the extinction of these enormous beasts of the ice age more than 10,000 years ago.Ī University of Cincinnati paleontologist refutes the latest timeline published in 2021 in the journal Nature that suggested mammoths met their end much more recently than we believed.
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