Advancing in time by more than a million years, scientists reported on Wednesday that they had recovered the world’s oldest known mammoth DNA whose carcasses had been frozen in Siberian permafrost since the ice age.
Extracted from molars extracted from already extinct elephants, the DNA dates back some 1.2 million years, scientists reported in the journal Nature. Until now, the oldest known DNA belonged to a prehistoric horse that lived between 560,000 and 780,000 years ago in present-day Yukon territory, Canada.
The researchers reconstructed relatively complete DNA sequences from three specimens as part of an effort to study the mammoth family tree. Variations in genetic material showed how 10-ton behemoths evolved at a time when half-kilometer layers of ice covered much of the northern hemisphere and revealed an unknown ancestor of mammoths that previously roamed North America. .
“With this mammoth DNA, you can look directly at evolution over more than a million years of time,” said Alfred Roca, a conservation geneticist at the University of Illinois at Urbana-Champaign who studies the evolution of elephants but which was not part of the group that conducted the new research. “You can see the changes in DNA and see how one species evolves into a very different species.”
At the height of the ice age about 20,000 years ago — what scientists call the last glacial maximum — the cold, dry meadows where mammoths lived were the most extensive habitat on earth. It extended from Spain to the east through Eurasia to Canada and from the Arctic islands in the south to China.