The human populations now predominant in Eurasia and East Asia probably split between 36,200 and 45,000 years ago, according to a study released Thursday.

Researchers used new techniques to analyze genetic samples from the shin bone of a young man who died at least 36,200 years ago near Kostenki-Borshchevo in what is now western Russia. The study, published in the journal Science, concludes that Kostenki man shared genetic sequences with contemporary Europeans, but not East Asians.

A separate study published in the journal Nature determined that a 45,000-year old sample found in Siberia contained sequences ancestral to both modern East Asians and Europeans. Taken together, these two studies suggest a time frame of about 9,000 years in which the two genetic populations could have diverged, said Eske Willerslev, an evolutionary biologist at the University of Copenhagen, Denmark.

Associated Press