By Bruce Bower, Science News
In Asia’s northern hinterlands not far from the Arctic Circle, Stone Age toolmakers left an evolutionary calling card that’s hard to read.
Artifacts found in this desolate region imply that the toolmakers adapted to frigid temperatures and dark winters, says a team led by archaeologist Ludovic Slimak of the University of Toulouse, France. Around that time, modern human groups in Europe and southwestern Asia underwent pivotal cultural changes. Some groups even reached Arctic spots near the new finds and left behind artifacts associated with that human cultural transition.
The new Arctic discoveries present a much tougher call. The stone implements—manufactured between 34,000 and 31,000 years ago at Byzovaya, a site in Russia’s Ural Mountains—resemble scraping and cutting tools associated with 130,000- to 30,000-year-old European Neandertals, Slimak and his colleagues report in the May 13 Science. To complicate matters, groups of Homo sapiens that lived in northern Africa and southwestern Asia between 200,000 and 45,000 years ago made tools like those of Neandertals.
If Neandertals held court at Byzovaya, then these stocky members of the human evolutionary family lived near groups of H. sapiens that reached the Russian Arctic by 36,000 years ago. If modern humans made the distinctive Byzovaya tools, “it would imply that Arctic H. sapiens groups preserved an older Stone Age culture after the expansion of modern societies in the rest of Eurasia,” Slimak says.
Stone tools attributed to anatomically modern human societies, which date to as early as 45,000 years ago in southern Russia, include small, rectangular blades and spear points. Such implements haven’t been found at Byzovaya.
Slimak’s discoveries resemble stone tools used not only by Stone Age people but by some recent hunter-gatherers to kill and butcher game, comments archaeologist John Hoffecker of the University Colorado at Boulder.
“Byzovaya probably provides more evidence that Stone Age humans rapidly pushed into the Arctic from lower latitudes in western Asia, at least on a seasonal basis,” Hoffecker says.
Human-made, old-school tools at Byzovaya would support the idea that stone blades and other cultural signatures of modern societies emerged in Europe, where people migrating from Africa competed for resources with native Neandertals, suggests archaeologist John Shea of Stony Brook University in New York.
It’s also possible that Byzovaya tools were the handiwork of a recently identified Neandertal relative, Shea says.
Slimak and his colleagues studied more than 300 stone artifacts and 4,000 animal bones that have been excavated by their team and another group since 1996. The artifacts include cutting tools and large rocks from which these implements had been removed with pounding stones. Nearly two dozen mammoth, reindeer and brown bear bones display butchery marks.
Age estimates for the Arctic site rest on measurements of carbon decay rates in animal bones from different soil layers and a calculation of the time elapsed since stone artifacts were buried.