Sequencing DNA from the 12,600-year-old skeleton of an infant found in central Montana, scientists have confirmed that early Native Americans descended from ancient Asians, not from Western Europeans, according to a study published in Naturetoday (February 12). This work, led by ancient DNA expert Eske Willerslev of the University of Copenhagen and his colleagues, marked the first ancient North American genome to have been fully sequenced.
The male infant, “Anzick-1,” who was thought to have been between 12 to 18 months old when he died, was excavated in 1968 from a burial site. His skeleton is the oldest known specimen unearthed in North America belonging to the Clovis people, who populated the continent between 13,000 and 12,600 years ago. The boy was buried alongside 125 ancient artifacts including, antler tools.
Tool remains from the Clovis culture form the most widespread archaeological complex throughout North America. But genetic samples of ancient Americans more than 5,000 years old are rare, making it difficult for scientists to piece together the migration patterns of ancient humans in the New World. For the present study, Willerslev’s team has shown that the infant shared about one-third of his genome with ancient people from Malta in Siberia, who also provided genes to people of present day Western Eurasia. The rest of Anzick-1’s DNA seems to have come from ancient East Asian people.
“This study provides direct evidence that modern Native Americas are directly descended from populations coming from eastern Asia, probably no more than a few thousand years before Clovis,” said archaeologistDavid Anderson from the University of Tennessee, who was not involved in the work.
Both genetic and archeological evidence previously pointed to this conclusion, but another theory, supported only by archaeological evidence, was that ancient Native Americans came from people who migrated across the Atlantic Ocean from Western Europe before the last Ice Age—the so-called Solutrean hypothesis. “This genetic study provides unequivocal evidence that this did not happen,” said coauthorMichael Waters, a geoarcheologist at the Texas A&M University.
Anzick-1’s genome also suggests that modern Native Americans are direct descendants of the Clovis population. The ancient genome is similar to those of peoples from both North and South America, suggesting that a single founding population migrated into the Americas close to the time of the last Ice Age.
“So there is a continuity of contemporary Native American populations with this Clovis individual dating back 12,600 years ago,” said Brian Kemp, a molecular anthropologist at the Washington State University, who was not involved in the study.
Comparisons of the ancient boy’s genome with genomic data from native North, Central, and South Americans further revealed that some native North American populations may have diverged early in the history of the first American people. Additional North American genomes will be needed to trace the evolution of the people that gave rise to the modern populations of the Americas.
Written By: Anna Azvolinsky
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