Washington, December 15 (ANI): An international team has used DNA samples from frozen dirt, not fossilized bones, to show that megafauna like the woolly mammoths survived the Ice Age and were possible alive as recently as 7,600 years ago.
This research, led by University of Alberta (U of A) Earth and Atmospheric Sciences professor Duane Froese, counters an important extinction theory, based on radiocarbon dating of bones and teeth.
That analysis concluded that more than half of the large mammals in North America (the 'megafauna') disappeared about 13,000 years ago.
In the new research, DNA samples recovered from Alaskan permafrost showed that woolly mammoths and ancient horses were still roaming through central Alaska about 10,000 years ago, and possibly as recently as 7600 years ago.
That predates the established record from fossil bones and teeth by at least 3,000 years.
The DNA samples were recovered from permafrost near the central Alaskan community of Stevens Village, on the banks of the Yukon River.
Analysis of the samples from soils that formed between 10,000 and 7600 years ago showed the presence of mammoth and horse DNA together with animals typically found in the region today, such as moose and arctic hare.
The challenge of dating extinction events is finding fossilized remains from the last animal left standing of any given species.
The chances of finding those exact bones are remote.
But, animals are constantly leaving behind tell-tale samples of DNA in the form of skin cells and feces in the environment.
That's what Froese and the other researchers found in the permafrost, at a depth and time line that radically changes the extinction date for two members of North America's megafauna in he late Pleistocene. (ANI)