At this time of year, many Canadians find themselves hankering for a tropical vacation to escape the cold, but a spectacular find on the Siberian tundra reveals that humans have been adept at making a living in the far north for much longer than previously thought. The discovery could even push back the clock on how soon the early peoples of Eurasia acquired the survival skills they needed to cross the Bering land bridge into North America.
The evidence is subtle: a set of telltale nicks, cuts and blows on a mammoth skeleton that was found near the Yenisei Gulf in northwestern Siberia and excavated by a team of Russian scientists in 2012.
Reporting in the journal Science on Thursday, team members said the damage to the skeleton is the unmistakable calling card of human hunters who brought down the mighty beast with stone tools. The researchers say the marks are similar to those found on other mammoth remains that are known to have been the work of human hunters because they were found with pieces of stone tools still embedded in the bone.
What makes the new discovery so remarkable is where and when the presumed hunt took place. The mammoth carcass was well above the Arctic Circle at a latitude that corresponds roughly to the northern end of Baffin Island. Radiocarbon dating of a tibia bone reveals it lay in the ground for some 45,000 years after the mammoth died, an age confirmed by additional clues from the soil layers above and below it.
Together with the remains of a settlement more than 1,000 kilometres to the east that has been shown to be of similar age, the new evidence points to a widespread human presence in the far north at least 10,000 years sooner than is widely accepted by anthropologists.
"Apparently, humans' ability to survive in the Arctic environment and their spread within the region … represents an important cultural and adaptational shift," the researchers wrote in their study. The northern expansion may have been triggered by developments in mammoth hunting techniques, they added.
The injuries on the skeleton suggest it was the work of hunters who were familiar with the mammoth's vulnerabilities and accustomed to felling such an enormous creature.
The team also speculates that the early arrival in Siberia would have set the stage for nomadic communities to penetrate into North America, perhaps even before the peak of the last ice age some 26,000 years ago.
"I think it's an important discovery that certainly seems to push back the time frame for human occupation of northern latitudes," said Greg Hare, senior projects archaeologist with the Yukon government. "Whether or not it has direct consequences for the peopling of the New World remains to be seen."
Currently, the oldest known traces of ancient people in Alaska, from a site known as Upward Sun River, are dated at about 11,500 years ago.
An earlier version of this story incorrectly stated that the 45,000 year old bones of a mammoth in Siberia were found embedded with small pieces of the stone weapons used by hunters. Such traces have been found in other, less-ancient mammoth skeletons.