A female infant who died about 11,500 years ago is shedding light on the Asian origins of Native Americans thanks to her DNA.
In a new study published on Nature, researchers decoded the infant’s complete DNA set and estimated the timing of key events in the ancestral history of Native Americans and indigenous communities in North, Central and South America.
The infant’s remains were discovered in a circular pit suspected of holding a ritual burial at the Upward Sun River archaeological site in Alaska in 2013. Locals named her “Xach’itee’aanenh t’eede gay” or “Sunrise Child-girl.”
Now, researchers led by academics from the Universities of Cambridge and Copenhagen have taken DNA from her skull, run a full genome sequence, and found that she descended from a single wave of migrants that crossed a land bridge along the Bering Strait during the last Ice Age.
“The study provides the first direct genomic evidence that all Native American ancestry can be traced back to the same source population during the last Ice Age,” Ben Potter, archaeologist at the University of Alaska Fairbanks, said via Reuters.
That source population was Asian. Around 36,000 years ago, a single ancestral Native American group separated from East Asians and crossed Beringia, the land bridge that previously connected Asia to Alaska.
Then, 16,000 years later, the group diverged into two lineages. The first spread throughout North and South America and became the ancestors of today’s Native Americans.
The second lineage, on the other hand, were the female infant’s people.
They were the Ancient Beringians, a newly-identified population that eventually disappeared and were likely absorbed by another group that settled in Alaska later.
“The Ancient Beringians diversified from other Native Americans before any ancient or living Native American population sequenced to date,” Eske Willerslev, lead author of the study holding positions at the University of Cambridge and University of Copenhagen, said via the University of Cambridge. “It’s basically a relict population of an ancestral group which was common to all Native Americans, so the sequenced genetic data gave us enormous potential in terms of answering questions relating to the early peopling of the Americas.”
“We were able to show that people probably entered Alaska before 20,000 years ago,” Willerslev added. “It’s the first time that we have had direct genomic evidence that all Native Americans can be traced back to one source population, via a single, founding migration event.”
Willerslev acknowledged claims that humans have been in the Americas up to 40,000 years, but such assumptions have not been proven.
If they were true, “they could not possibly have been the direct ancestors to contemporary Native Americans,” he said.