A 14,000-year-old tooth discovered in Siberia once belonged to the oldest known close relative of Native Americans outside the Americas, representing the "deepest connection" between the peoples of Eurasia and the Americas ever found.
Reported in the journal Cell, geneticists from the Max Planck Institute for the Science of Human History in Germany sequenced the genome of 19 ancient humans found in the 1970s around the Lake Baikal region of Siberia. The individuals lived over a period of 10,000 years, providing the researchers with a detailed history of the Eurasian Steppe ranging from the Upper Paleolithic to the Early Bronze Ages.
One of the genomes, sequenced from a speck of tooth, is thought to be exceptionally old. Based on the radiocarbon dating of other remains found alongside the tooth, it's estimated to be about 14,000 years old. The genome revealed that the individual was a male with the same genes of Ancient North Eurasian and Northeast Asian ancestry found in present-day Native American people, making him a Eurasian “cousin” of Native Americans alive today.
“This study reveals the deepest link between Upper Paleolithic Siberians and First Americans,” He Yu, first author of the study from the Department of Archaeogenetics at Max Planck, said in a statement. “We believe this could shed light on future studies about Native American population history.”
All of this fits in neatly with the widely accepted story of the Americas. The early human settlement of the Americas is surprisingly hazy and full of disagreement, but most researchers believe humans arrived on the continent no earlier than 23,000 years ago. The traditional explanation says a population of hunters crossed the Bering Strait over a land bridge, known as Beringia, that stretched between Siberia to Alaska until around 12,000 BCE.
One surprising discovery from the project was the presence of Yersinia pestis, the notorious bacteria that’s responsible for the plague. Isotope analysis of one of the infected individuals from the Early Bronze Age shows that the strain of the bacterium was not from the local area. This indicates that people – along with their cultures, genetics, and pathogens – were highly mobile around this time.
“This easternmost appearance of ancient Y. pestis strains is likely suggestive of long-range mobility during the Bronze Age,” explains Maria Spyrou, one of the study’s co-authors. “In the future, with the generation of additional data we hope to delineate the spreading patterns of plague in more detail,” concludes Johannes Krause, senior author of the study.