It has become commonplace to accept that humans came to the New World from Asia across the Bering Strait. It has also become commonly accepted that the people who crossed this strait were in fact Homo sapiens sapiens (and not some earlier form of the species) and that they did not begin this migration before the terminal Pleistocene era.
These assumptions are based upon a number of aspects of the archaeological and biological record. The lack of human skeletal remains in the New World before the end of the Pleistocene sets the period before which migration seems unlikely to have occurred. The biological connections between the peoples of Asia and the native peoples of the Americas suggest that at one time these groups formed a common and united gene pool. And the fact that dental variation in the Americas is less than that in Asia suggests that the American populations are of relatively recent settlement (Greenberg, Turner, & Zegura, 1986, p. 477).
So far, this presents a fairly simple and fairly straightforward view of this major and significant migration, and one with which most people are fairly familiar. However, these points of evidence also raise interesting questions. The most common picture that the lay person probably has of this migration is an event that occurred with relative speed. In other words, a single (if extended) migration during which a large number of people traveled as a single group over the land bridge to the New World and then settled here, after which they became (because of geological changes) permanently isolated from their Asian ancestors.
However, the biological, linguistic and archaeological evidence suggests that in fact this was not the case at all, but rather that Homo sapiens came to the New World in three separate waves. This paper examines the evidence supporting that assertion, weighing the strength of three different areas of evidence รป that having to do with the dentition of both Asian...