The mammoths' swan song revised

[Adsos Letter]

Source: EurekAlert
University of Copenhagen
Professor Eske Willerslev

Woolly mammoths and prehistoric horses grazed on the North American plains for several thousand years longer than hitherto assumed
This is shown by samples of ancient DNA, analysed by an international team of research scientists under the leadership of Professor Eske Willerslev from Copenhagen University. Analyses of ancient DNA thereby once again revoke results of more common methods of dating, such as carbon 14 analysis of bone and tooth remains from extinct animals. These methods which had previously dated the extinction of mammoths and prehistoric horses in Central Asia to within 13-15,000 years ago. But with the DNA-test methods of Eske Willerslev and his colleagues, this boundary has now moved between 2,600 and 5,600 years closer to our time and has thus revised our previous opinion of when the last mammoths and prehistoric horses grazed on the North American Plains.

The ancient DNA that formed the basis for this sensational result, was discovered by scientists in samples of soil from the permafrost tundra surrounding the windswept town of Stevens Village on the bank of the Yukon River in Central Alaska.

Professor Eske Willerslev says about his discovery:

"In principle, one can take a pinch of soil and uncover which living creatures, animals and plants lived in the area half a million years back in time. With ancient DNA analysis, we are completely independent of skeletons, bones, teeth and other macro-fossil evidence from extinct animals. This greatly increases the possibility of finding evidence of the existence of a species through time. Whilst an animal leaves only a single corpse when it dies, it leaves quantities of DNA traces through urine and faeces whilst it is still alive. It is these DNA traces which we find in the soil."

When the remains of the last member of an extinct species were hard to find, Willerslev and a team of international research scientists decided to carry out an expedition to Central Alaska to solve the riddle of "The last surviving mammoths" using ancient-DNA tests from permafrost soil.

http://www.eurekalert.org/pub_releases/2009-12/uoc-tms121409.php