Ancient DNA study suggests first humans arrived in Americas 20,000 years ago

A new genetic review published in ‘Current Opinion in Genetics & Development’ by researchers from the University of Kansas suggests that the ancestors of Indigenous peoples arrived in the Americas during the extreme conditions of the last Ice Age, approximately 20,000 years ago.

By cross-referencing ancient DNA from roughly 257 complete genomes and 1,204 partial genomes with archaeological sites, the study aims to narrow the long-standing debate regarding human arrival. The findings indicate that these ancestors were related to ancient populations from North Asia and Beringia, a land bridge that connected Asia and North America when sea levels were low.

The research helps contextualize various archaeological sites, such as White Sands in New Mexico and Swan Point in Alaska, while noting that genetic patterns make it difficult to support much older arrival theories, such as those proposed at the Cerutti site in California.