Reaching back in time more than a million years, scientists reported Wednesday that they had recovered the world’s oldest known DNA from mammoths whose carcasses had lain frozen in the Siberian permafrost since the Ice Age.
Extracted from molars taken from the long-extinct elephants, the DNA dates back about 1.2 million years, the scientists reported in the journal Nature. Until now, the most ancient 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 sequences of DNA from three specimens as part of an effort to study the mammoth family tree. Variations in the genetic material showed how the 10-ton tusked behemoths evolved in an era when mile-thick ice sheets covered much of the Northern Hemisphere—and revealed a previously unknown ancestor of the mammoths that once roamed North America.
“With this mammoth DNA, you can look directly at evolution across more than a million years of time,” said Alfred Roca, a conservation geneticist at the University of Illinois at Urbana-Champaign who studies elephant evolution but who wasn’t part of the group that conducted the new research. “You can see the changes in the DNA and watch one species evolve into a very different species.”
At the height of 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.
Read More: World’s Oldest DNA Unlocks Lineage of Ice Age Mammoths