DNA reveals clues to the Siberian ancestors of the first Americans
Previously unknown Ice Age travelers crossed a land bridge from Russia into North America
New findings offer a clearer picture of the ancestors of modern Siberians — and Native Americans. They come from groups that lived long ago in Asia. Some of their members mixed and then later spread into North America.
Three distinct groups of people migrated to Siberia. During the later Ice Age, some of them migrated into North America.That’s the finding of a new study. Clues to those migrations can be seen today in the genes of Siberians and Native Americans.
The story of these peoples is complex. Each incoming group largely replaced people already living in an area. But some mating between the newcomers and old-timers also took place, notes study leader Martin Sikora. An evolutionary geneticist, he works at the University of Copenhagen in Denmark.
His team’s findings appeared online June 5 in Nature.
Sikora’s group analyzed DNA from 34 people. All had been buried between 31,600 and 600 years ago in Siberia, in East Asia or in Finland. Sikora’s group compared their DNA with DNA collected earlier from very ancient and modern people who had lived across Europe, Asia and North America.
Two teeth proved important. They had been dug up at a Russian site. Known as Yana Rhinoceros Horn. This site was some 31,600 years old. The teeth there came from an unknown group of people. The researchers named this population the Ancient North Siberians. Around 38,000 years ago, these people migrated to Siberia from Europe and Asia. They adapted quickly to the region’s frigid Ice Age conditions, the team reports.
Some 30,000 years ago, ancient North Siberians traveled onto a land bridge. It linked Asia and North America. There, these people mated with East Asians who also had moved to the land bridge. Their mixing created another genetically distinct group. The researchers named them the Ancient Palaeo-Siberians.
Over the next 10,000 years the climate warmed. It also became less harsh. At this point, some of the Ancient Palaeo-Siberians returned to Siberia. There, they slowly replaced the Yana people.
Other Ancient Palaeo-Siberians trekked from the land bridge into North America. Over time, rising waters swamped the land bridge. Later, between 11,000 and 4,000 years ago, some of their relatives returned to Siberia by sea. They became the ancestors to many of today’s Siberians.
A nearly 10,000-year-old Siberian man held the key to linking all these groups. His DNA helped identify genetic similarities between Ancient Palaeo-Siberians and modern peoples.