Modern Humans Traveled Across The Eurasian Steppe 45,000 Years Ago

"These objects existed before, in Siberia, but not to such a degree of standardization. The most intriguing (aspect) is that they are produced in a complicated yet systematic way -- and that seems to be the signature of a human group that shares a common technical and cultural background."

Researchers ruled out Neanderthals or Denisovans as the site's occupants. "Although we found no human remains at the site, the dates we obtained match the age of the earliest Homo sapiens found in Siberia," said Zwyns, adding that after carefully considering other options, we suggest that this change in technology illustrates movements of Homo sapiens in the region."

Evidence of soil development suggests that the climate for a period became warmer and wetter, making the normally cold and dry region more hospitable to grazing animals and humans.

Preliminary analysis identifies bone fragments at the site as large (wild cattle or bison) and medium size bovids (wild sheep, goat) and horses, which frequented the open steppe, forests and tundra during the Pleistocene -- another sign of human occupation at the site.

The dates for the stone tools also match the age estimates obtained from genetic data for the earliest encounter between Homo sapiens and the Denisovans.

"Although we don't know yet where the meeting happened, it seems that the Denisovans passed along genes that will later help Homo sapiens settling down in high altitude and to survive hypoxia on the Tibetan Plateau," Zwyns said.

"From this point of view, the site of Tolbor-16 is an important archaeological link connecting Siberia with Northwest China on a route where Homo sapiens had multiple possibilities to meet local populations such as the Denisovans."