Fossil evidence of humans hunting mammoths in the Eurasian Arctic puts early humans in the region tens of thousands of years earlier than had previously been believed, researchers say.
A frozen mammoth carcass in Siberia showing cuts and scrapes form human hunting weapons has been dated to about 45,000 years ago, 10,000 years earlier than humans were thought to have reached that far north, they say.
"The mammoth is almost 72 degrees North," says Vladimir Pitulko, an archaeologist at the Institute for the History of Material Culture (IHMC) of the Russian Academy of Sciences in St. Petersburg.
The Arctic Circle, at the top of Canada and Russia, begins at 66.32 degrees North latitude.
That puts the new find more than a thousand miles further north than previously known old human habitation sites south of the Arctic Circle, says Pitulko, a co-author of a study appearing in the journal Science.
The frozen mammoth, excavated from permafrost in the central Siberian Arctic, showed marks and slices on a number of its bones resembling those seen on mammoth bones from a much younger archaeological site in Siberia where humans were known to hunt mammoths, the researchers say.
Dents in rib bones were likely made by spears, they note, while damage to one of the animal's tusks suggests the human hunters were attempting to chop part of it away.
Experts say the age of the finding, confirmed by radiocarbon dating of several bones of the carcass, suggest early humans learned how to cope and survive in the extreme cold of the Arctic much earlier than was previously considered.
That they did so is "a mighty, impressive achievement," says paleontologist Robin Dennell of the University of Sheffield in England, who wasn't involved in the recent work.
"What we don't know is whether this was a successful long-term adaptation or a short-lived heroic failure," he suggests.
The findings may also lend support to the possibility that early humans made their way out of Africa earlier than previously thought, other experts say.
"To penetrate beyond 70 degrees North as early as this evidence is suggesting, our tropics-born ancestors — assuming these Arctic pioneers belonged to our own species Homo sapiens — had to probably start their out-of Africa-and-into-Eurasia odyssey much earlier than 50 or 60 thousand years ago," says Paleolithic archaeologist Leonid Vishnyatsky, an IHMC colleague of Pitulko who was not directly involved in the study.
Eventually, arriving so far north would have involved learning to survive in many varied kinds of environments, he says.
"[A]nd that doesn't happen overnight," he says.