A new old link between Siberia and America

Researchers have revealed the oldest and deepest connection yet found between the peoples of Siberia and the Americas, dating back 14,000 years. 

Their study of prehistoric hunter-gatherers around Lake Baikal in southern Siberia also demonstrates human mobility, and hence connectivity, across Eurasia during the Early Bronze Age, they say.

Led by Germany’s Max Planck Institute for the Science of Human History, the work involved human population genetics, ancient pathogen genomics and isotope analysis, and included the sequencing of 19 human genomes.

“This study reveals the deepest link between Upper Paleolithic Siberians and First Americans,” says He Yu, first author of a paper in the journal Cell. “We believe this could shed light on future studies about Native American population history.”

Previous studies have indicated a connection between Siberian and American populations, but a 14,000-year-old individual analysed in the new study is the oldest to carry the mixed ancestry present in Native Americans. 

Using an extremely fragmented tooth excavated in 1962 at the Ust-Kyahta-3 site located on Selenga River in the Kyakhtinski region of Russia, the researchers generated a shotgun-sequenced genome enabled by cutting edge techniques in molecular biology.

They found that both this individual and a younger one from northeast Siberia share the same genetic mixture of Ancient North Eurasian (ANE) and Northeast Asian (NEA) ancestry found in Native Americans.

This suggests, they say, that the ancestry which later gave rise to Native Americans in North and South America was much more widely distributed than previously assumed, and that this population experienced frequent genetic contacts with NEA populations, resulting in varying admixture proportions across time and space.

The study also presents connectivity within Eurasia, as evidenced in human and pathogen genomes as well as stable isotope analysis. Combining these lines of evidence, the researchers were able to produce a detailed description of the population history in the Lake Baikal region, which began some 40,000 years ago.

The presence of Eastern European steppe-related ancestry is evidence of contact between southern Siberian and western Eurasian steppe populations in the preamble to the Early Bronze Age, the researchers say, an era characterised by increasing social and technological complexity. 

The surprising presence of Yersinia pestis, the plague-causing pathogen, points to further wide-ranging contacts. Isotope analysis of one of the infected individuals revealed a non-local signal, suggesting origins outside the region of discovery.