"America Unearthed" Guest Jim Chatters: New DNA Evidence Links Paleoindians to Modern Native Americans

Several alert readers sent me links to a variety of news articles announcing the discovery of a 12,000 year old skeleton in the Yucatán Peninsula, which was reported yesterday in the online version of the journal Science in the article “Late Pleistocene Human Skeleton and mtDNA Link Paleoamericans and Modern Native Americans.” The bones, which were discovered underwater along with the remains of Ice Age fauna, are among the oldest ever found in the Americas. Tests of her mitochondrial DNA, however, are causing even more of a stir, helping to pinpoint the origin of the first Americans—and suggesting that some of the wilder claims about their origins are wrong.

First, a word of caution: Because the DNA sample came from only one individual, the conclusions are not, strictly speaking, definitive. However, the scientists who tested the bones of the girl they named Naia, who died around the age of 15, found that her mitochondrial DNA provided a direct connection to the people of Beringia, long thought to be the origin point for the first Americans. She had a DNA marker common throughout the Americas and which is believed to have evolved in Beringia among a genetically isolated population before the peopling of the Americas.

According to the researchers, this has several dramatic implications:

1. The first Americans therefore came from Beringia and not, as some have suggested, from the East Asian population that gave rise to the Polynesians, or from Europe.
2. The Americas were most likely populated in one major wave rather than a series of smaller migrations.
3. Morphological changes between Paleoindians and modern Native Americans are the result of rapid evolution within the Americas, not due to an influx of genes from Asia or Europe, or the “replacement” of the Paleoindians with successive migrations from Asia.

As the paper put it, “The differences in craniofacial form between Native Americans and their Paleoamerican predecessors are best explained as evolutionary changes that postdate the divergence of Beringians from their Siberian ancestors.”

These conclusions appear in a paper whose lead author is none other than James Chatters, whom Scott Wolter has repeatedly praised, as recently as April 22 on Frank from Queens’s podcast, as being one of the few archaeologists open to the possibility that Kennewick Man was not related to modern Native Americans. You will recall that Chatters appeared on America Unearthed a few months ago to talk about his previous conclusion, before the most recent evidence, that based on skull shape Kennewick Man was most closely related to Polynesians and the Ainu of Japan, prompting Wolter to incorrectly conclude that Polynesians were in the Americas at least 9,600 years ago. (Polynesians would not become a separate people and culture for at least 8,000 years.) Both Chatters and Wolter placed a great deal of emphasis on the importance of skull shape for determining affiliation. At the time I noted that Chatters was an outlier among physical anthropologists, who preferred to see Paleoindian skulls as examples of genetic diversity in the founding population of the Americas which gradually diminished over time.

Chatters has now concluded that the Polynesian hypothesis is no longer supportable given the new DNA evidence. The “Polynesian” appearance of Paleoindian skulls reflects an ancestral Beringian population which evolved over time in a different direction. Chatters now believes that Paleoindians and modern Native Americans are a single people. “Do they come from different parts of the world? This comes back with the answer, probably not,” he told the Washington Post yesterday. His coauthor, Deborah Bolnick, was more explicit. According to her, the weight of evidence shows that “Native Americans can be traced to a Beringian source population.”

This newest evidence does not conclusively exclude other Asian or even European migrations to the Americas, but it narrows the area where such migrants could have conceivably impacted American prehistory. In theory, of course, the Solutreans could have come around 20,000 BCE and then been killed off by the Paleoamericans in 11,000 BCE, as some fringe history believers argue. But the evidence that the supposed “Caucasoid” skeletons of the Americas, like Kennewick Man and other Paleoamericans, are morphologically identical to one now shown to be genetically related to modern Native Americans and ancestral Beringian populations makes such claims much less likely.