More than a million years ago, scientists reported Wednesday that they had recovered the world’s oldest known DNA from mammoths whose carcasses had been frozen in the Siberian permafrost since the Ice Age.
The DNA, extracted from molars from the long-extinct elephants, dates back about 1.2 million years, the 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 what is now the Yukon Territory in Canada.
The researchers reconstructed relatively complete DNA sequences from three copies as part of an effort to study the mammoth family tree. Variations in the genetic material showed how the 10-ton tusk giants evolved in an era when miles of ice sheets covered much of the Northern Hemisphere – revealing a previously unknown ancestor to the mammoths that once roamed North America.
“With this gigantic DNA, you can look directly at evolution for over a million years,” said Alfred Roca, a conservation geneticist at the University of Illinois at Urbana-Champaign who studies elephant evolution but was not part of the group. who conducted the new research. “You can see the changes in the DNA and see how one species evolves into a completely different species.”
At the height of the Ice Age, some 20,000 years ago – what scientists call the last glacial maximum – the cold, dry grassland where the mammoths lived was the most extensive habitat on Earth. It stretched from Spain eastward across Eurasia to Canada and from the Arctic islands southward to China.