A New History of the First Peoples in the Americas
Until Columbus, the Americas were populated by pockets of tribal groups distributed up and down both north and south continents. There are dozens of individual cultures that have been identified by age, location, and specific technologies—and via newer ways of knowing the past, including genetics and linguistics. Scholars have hypothesized various patterns of migration from Beringia into the Americas. Over time, it has been suggested that there were multiple waves, or that a certain people with particular technologies spread from north all the way south.
No people are completely static, and genes less so.
Both ideas have now fallen from grace. The multiple-waves theory has failed as a model because the linguistic similarities used to show patterns of migration are just not that convincing. And the second theory fails because of timing. Cultures are often named and known by the technology that they left behind. In New Mexico there is a small town called Clovis, population 37,000. In the 1930s, projectile points resembling spearheads and other hunting paraphernalia were found in an archaeological site nearby, dating from around 13,000 years ago. These were knapped on both sides—bifaced with fluted tips. It had been thought that it was the inventors of these tools who had been the first people to spread up and down the continents. But there’s evidence of humans living in southern Chile 12,500 years ago without Clovis technology. These people are too far away to show a direct link between them and the Clovis in such a way that indicates the Clovis being the aboriginals of South America.
Today, the emerging theory is that the people up in the Bluefish Caves [in Yukon, Canada] some 24,000 years ago were the founders, and that they represent a culture that was isolated for thousands of years up in the cold north, incubating a population that would eventually seed everywhere else. This idea has become known as Beringian Standstill. Those founders had split from known populations in Siberian Asia some 40,000 years ago, come across Beringia, and stayed put until around 16,000 years ago.