Human evolution; migration from Asia to N. America (Introduction)

by David Turell , Wednesday, May 20, 2020, 18:57 (1436 days ago) @ David Turell

Across an old land bridge:

https://www.sciencenews.org/article/oldest-genetic-link-asians-native-americans-siberia

"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, the southern Siberian individual inherited genes from two Asian populations that contributed to the genetic makeup of Native Americans.

"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."

Comment: Migrating out of Africa, modern humans did not reach the Americas until about 16,000 years ago. And yet many of the Pacific islands were fully colonized much earlier. Not Hawaii which occurred less than 3,000 years ago. Interesting that travel by sea was faster than over land. At sea you have no idea what is over the horizon, but they apparently had enough provisions to live to see new unknown islands.