We have reasonably clear genetic evidence that the most likely candidate for the source of Native American populations is somewhere in east Asia, says Noah A. Rosenberg, Ph.D., assistant professor of human genetics and assistant research professor of bioinformatics at the Center for Computational Medicine and Biology at the U-M Medical School and assistant research professor at the U-M Life Sciences Institute.
If there were a large number of migrations, and most of the source groups didnt have the variant, then we would not see the widespread presence of the mutation in the Americas, he says.
Rosenberg has previously studied the same set of 678 genetic markers used in the new study in 50 populations around the world, to learn which populations are genetically similar and what migration patterns might explain the similarities. For North and South America, the current research breaks new ground by looking at a large number of native populations using a large number of markers.
The pattern the research uncovered that as the founding populations moved south from the Bering Strait, genetic diversity declined is what one would expect when migration is relatively recent, says Mattias Jakobsson, Ph.D., co-first author of the paper and a post-doctoral fellow in human genetics at the U-M Medical School and the U-M Center for Computational Medicine and Biology. There has not been time yet for mutations that typically occur over longer periods to diversify the gene pool.
In addition, the studys findings hint at supporting evidence for scholars who believe early inhabitants followed the coasts to spread south into South America, rather than moving in waves across the interior.
Assuming a migration route along the coast provides a slightly better fit with the pattern we see in genetic diversity, Rosenberg says.
The study also f
|Contact: Anne Rueter|
University of Michigan Health System