A Texas A&M TAMU Times report notes that a DNA study of skeletal remains believed to be that of a young boy who lived and died about 24,000 years ago in Siberia, could turn the archaeological world on its head. DNA sequencing of the ancient child’s genome shows that while up to one-third of his ancestry can be traced back to Europe, nearly 30 percent of modern Native Americans’ ancestry also came from this youngster’s gene pool. Which suggests that First Americans came directly from Siberia, according to a research team that includes Dr. Kelly Graf, an assistant professor in the Center for the Study of First Americans and Department of Anthropology at Texas A&M.
The international team is spearheaded by palaeogeneticist Eske Willerslev, director of Centre of Excellence in GeoGenetics and the National CryoBank and Sequencing Facility at the National History Museum and the Biological Institute, University of Copenhagen, and Maanasa Raghaven from the Centre for GeoGenetics at the University of Copenhagen, Denmark, and includes researchers from Sweden, Russia, United Kingdom, University of Chicago and University of California-Berkeley. Their work, funded by the Danish National Science Foundation, Lundbeck Foundation, and the National Science Foundation, is published in the current issue of Nature magazine.
A Science magazine article by science writer Ed Jong, entitled “America’s natives have European roots,” reports that the palaeolithic era skeleton, along with flint tools, a beaded necklace and what appears to be pendant-like items, all apparently placed in the burial as “grave goods,” first discovered in the late 1920s near the village of Mal’ta near Lake Baikal in south-central Siberia, and excavated by Russian archaeologists over a 20-year period ending in 1958 ” The remains, since then referred to as “the Mal’ta child,” add a new root to the family tree of indigenous Americans. While some of the New World’s native ancestry clearly traces back to east Asia, sequencing of the 3 to 4 year old Mal’ta boy’s genome — the oldest known of any modern human — reveals that up to one-third of that ancestry can also be traced back to Europe.
The co-authors of the Science study, entitled “Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans” (Nature 2013 doi:10.1038/nature12736) say that to their knowledge the Mal’ta boy’s skeleton (MA-1) carries the oldest anatomically modern human genome reported to date, and that its mitochondrial genome belongs to haplogroup U, commonly found among modern humans who first populated Europe about 44,000 years ago, and which has also been found at high frequency among Upper Palaeolithic and Mesolithic European hunter-gatherers. They note that the Y chromosome of MA-1 is basal to modern-day western Eurasians and near the root of most Native American lineages as well. Similarly, they found autosomal evidence that MA-1 is basal to modern-day western Eurasians and genetically closely related to modern-day Native Americans, with no close affinity to east Asians. Those findings suggest that populations related to contemporary western Eurasians had a more north-easterly distribution 24,000 years ago than commonly thought, and moreover, they estimate that 14 to 38% of Native American ancestry may originate through gene flow from this ancient population.
In a nutshell, the researchers’ findings “reveal that western Eurasian genetic signatures in modern-day Native Americans derive not only from post-Columbian admixture, as commonly thought, but also from a mixed ancestry of the First Americans.”
“At some point in the past, a branch of east Asians and a branch of western Eurasians met each other and had sex a lot,” Dr. Willerslev, who also led the sequencing of the boy’s genome, told Ed Jong, adding that this mixing of genes created Native American races that later populated both North and South America.
Drs. Graf and Willerslev conceived the project and in 2009 traveled to the Hermitage State Museum in St. Petersburg, Russia, where the remains are now housed, and arranged to collect a DNA sample from one of the Mal’ta boy’s arm bones. “We hoped that he could tell us something about the early peopling of the Americas, but it was a complete long shot,” Dr, Willerslev told Jong, “Genetically, this individual had no east Asian resemblance but looked like Europeans and people from west Asia. The thing that was really mind-blowing was that there were signatures you only see in today’s Native Americans,” and that are consistent among peoples from across the Americas, implying that it could not have come from European settlers who arrived after Columbus and must reflect ancient ancestry. This study sheds new light on why some early Native American skeletons such as Kennewick Man were interpreted to have some European traits.
Texas A&M’s Dr. Kelly Graf, who helped extract DNA material from the boy’s upper arm, comments in the TAMU Times report that “the result surprised all of us quite a bit. It shows he had close genetic ties to today’s Native Americans and some western Eurasians, specifically some groups living in central Asia, South Asia, and Europe. Also, he shared close genetic ties with other Ice-Age western Eurasians living in European Russia, Czech Republic and even Germany. We think these Ice-Age people were quite mobile and capable of maintaining a far-reaching gene pool that extended from central Siberia all the way west to central Europe.”
The genetic research adds a new element to the controversy over the time line of human migration into the Western Hemisphere via the Beringia land bridge and ultimately North America. “Though our results cannot speak directly to this debate, they do indicate Native American ancestors could have been in Beringia — extreme northeastern Russia and Alaska — any time after 24,000 years ago and therefore could have colonized Alaska and the Americas much earlier than 14,500 years ago, the age suggested by the archaeological record,” says Dr. Graf. “What we need to do is continue searching for earlier sites and additional clues to piece together this very big puzzle.”
Texas A&M University
University of Copenhagen
Texas A&M University
Hermitage State Museum, St. Petersburg, Russia
University of Copenhagen