Asian migration to north americaUploader: Brycen 19 days ago Subscribe 1960
The oldest of these is a site in Texas, 40 miles northwest of Austin, which dates to 15, years ago. He thought the land bridge was still in existence during his lifetime. Genetics Society of America. There exist a number of theories for pre-Columbian trans-oceanic migrations into the Americas. A third model, the "Recurrent Gene Flow" [RGF] model, attempts to reconcile the two, arguing that circumarctic gene flow after the initial migration could account for morphological changes. The second theory is the long chronology theory, which proposes that the first group of people entered the Americas at a much earlier date, possibly before 40, years ago,    followed by a much later second wave of immigrants.