The study follows up on earlier research that found a unique variant of a genetic marker in the DNA of modern descendants of Native Americans. “While earlier studies have already supported this conclusion, what’s different about our work is that it provides the first solid data that simply cannot be reconciled with multiple ancestral populations,” said Kari Britt Schroeder of the University of California, one of the authors of the study.
As a result of the previous research, the so-called “9-repeat allele” (or variant) was found in all of the 41 Native American and Asian (from the western side of the Bering Strait) populations that were sampled. At the same time, the allele was absent in all 54 of the Eurasian, African and Oceanian groups that were also sampled in the study.
The researchers supposed that the distribution of the allele was due to the fact that all these ethnic groups (modern Native Americans, Greenlanders and western Beringians) derived from a common founder population, which had been isolated from the rest of the Asian continent thousands of years prior to their migration to the Americas.
This explanation was persuasive enough; however, there was no strong evidence to support it. There were two other plausible versions to explain the distribution of the 9-repeat allele among the modern descendants of Native Americans.
