First complete genome sequence of an ancient North American offers clues to Native American ancestry
A new study published in the journal Nature has revealed the first ever genome sequence of an individual that belonged to the Clovis culture, a prehistoric culture that inhabited the Americas around 13,500 years ago. The study is helping to piece together Native American ancestry.
The genetic analysis was carried out on a male infant discovered in 1968, known as ‘Anzick boy’, who lived 12,600 years ago. He was found at a burial site along with about 125 artefacts, including Clovis fluted spear points and tools made from antlers. It is the oldest burial found in North America, and the only known Clovis burial.
Scientists investigated a prehistoric culture known as the Clovis, named after sites discovered near Clovis, New Mexico. For more than 20 years anthropologists have debated whether they arrived in the New World by walking over a land bridge across the Bering Strait, or by sea from southwest Europe millennia earlier, the so-called ‘Solutrean hypothesis’. There has also been debate over whether the Clovis were the first people to arrive in the Americas. For more than half a century, archaeologists thought the Clovis were the first, but recently, evidence has emerged showing that humans were in the New World before the Clovis. These controversies have made it difficult to piece together the true origins of the Native American population. However, the findings of the latest study help to resolve some of the unanswered questions.
The study found that the Clovis people are the direct ancestors of many contemporary Native Americans, and are closely related to all Native Americans. "We found the genome of this boy is closely related to all Native Americans of today than to any other peoples around the world," study co-author Eske Willerslev of the University of Copenhagen
The DNA analysis also links Native Americans today to ancient migrants from easternmost Asia. This research "has settled the long-standing debate about the origins of the Clovis," Willerslev said. "We can say the Solutrean theory suggesting Clovis originated from people in Europe doesn't fit our results." Anthropological geneticist Jennifer Raff of the University of Texas, added that the study “is the final shovelful of dirt” on the European hypothesis.
The scientists also discovered evidence of a deep genetic divergence that occurred between northern Native American groups and those from Central and South America that happened before the Clovis era. Specifically, although most South Americans and Mexicans are part of the Anzick lineage and therefore Clovis, northern Canadian groups belong to another lineage.
However, not all experts are convinced. "We definitely have some stuff here in the east of the United States that is older than anything they have in the west," said anthropologist Dennis Stanford of the Smithsonian Institution, a proponent of the out-of-Europe model. "They've been reliably dated to 20,000 years ago," too early for migrants from Beringia to have made the trek, he said, and strongly resemble Solutrean artefacts.
The debate about Native American origins is far from over, but scientists hope the Anzick boy has yielded all his secrets:, he will be reburied in a traditional ceremony by early summer.