Tens of thousands of years ago, the places that have since been named Russia and Alaska were not separated by water, but connected by a continuous bridge of land. People walked across that land, heading eastward from Asia. For a time, their journey was blocked by two gigantic ice sheets that smothered most of what is now Canada. But once the ice started melting, those early pioneers—the ancestors of today’s Native Americans—spread southward.
Sometime between 14,600 and 17,500 years ago, they split into two main lineages: a northern group and a southern one. The northern group gave rise to the Algonquian-, Na-Dené-, Salishan-, and Tsimshian-speaking peoples of Canada, and to the Ancient One—a famous 8,500-year-old skeleton found in Kennewick, Washington. The southern group included the ancestors of modern Central and South Americans, as well as Anzick-1—a 12,600 year old infant skeleton from the widespread Clovis culture.
This narrative comes from archaeology, linguistics, and most recently, genetics. By studying and comparing the DNA of the Ancient One, Anzick-1, and two infants from Upward Sun River in Alaska, scientists have started to piece together the movements—and existence—of ancient peoples. “There have been a lot of interesting ancient DNA findings in the Americas, but always based on one or two genomes,” says Christiana “Freddi” Scheib, from the University of Tartu. “I wanted to see if we could fill out this picture by getting as many ancient genomes as we could.”