DNA gleaned from a roughly 14,000-year-old fragment of a human
tooth suggests that people inhabiting a surprisingly large swath of Asia were the
ancestors of the first Americans.

This tooth, unearthed at a site just south of Lake Baikal in
southern Siberia, provides
the oldest known genetic link
between Stone Age Asians and ancient American
settlers, scientists report May 20 in Cell.
Present-day Native Americans in North and South America are partly related to
those early arrivals, the team says.

Like a previously studied, nearly
10,000-year-old man in northeastern Siberia
(SN: 6/7/19), the southern Siberian individual inherited genes from
two Asian populations that contributed to the
genetic makeup of Native Americans
(SN:
2/10/10
).

DNA from a partial tooth (shown from different angles) found in Siberia represents the oldest known genetic connection between Stone Age Asians and the first Americans.G. Pavlenok, H. Yu et al/Cell 2020
DNA from a partial tooth (shown from different angles) found in Siberia represents the oldest known genetic connection between Stone Age Asians and the first Americans.G. Pavlenok, H. Yu et al/Cell 2020

Using DNA already extracted from human remains at several
ancient Siberian sites, archaeogeneticist He Yu of the Max Planck Institute for
the Science of Human History in Jena, Germany, and her colleagues conclude that
one of those ancestral populations originated in northeastern Asia, east of
Lake Baikal. The other hailed from north-central Asia, west of the lake.

It’s unclear where and when members of those two populations
met up and mingled. But mating between them produced a mix of DNA that
characterized people who crossed a
land bridge to what’s now Alaska
perhaps 16,000 years ago or more, the
researchers say (SN: 8/8/18).

Until now, many researchers have assumed that Native Americans’ genetic roots lay only in northeastern Asia.