Earliest American Genome Proves Siberian Origins of Native Peoples

The sequencing of DNA from the earliest known North American remains has provided the first genetic confirmation of Native American ancestry, quashed a controversial alternative theory and hinted at possible migration patterns that may revise our understanding of population dispersal from modern-day Alaska to the southern tip of Chile.

Whew. Pretty impressive achievements for a baby.

Researchers today announced the successful whole-genome sequencing of Anzick-1, the remains of an infant boy who lived roughly 12,600 years ago. The remains were discovered in central Montana in 1968 during a construction project. Anzick-1 was a crucial find for archaeologists even before scientists completed the DNA analysis the childs remains are the oldest known burial in North America and the only human remains ever found that are definitively associated with the Clovis people, the continents first known indigenous culture.

Anzick-1s DNA allowed researchers to confirm genetically, for the first time, that all native peoples of North and South America descended from ancestors who arrived via land bridges from East Asia, possibly in a single migration. While there has been ample archeological evidence of the East Asian origin of Native Americans, conclusive proof based on DNA had been absent until now. Even a recent study comparing the genes of ancient Siberian remains with those of modern Native Americans had not been as conclusive.

The sequencing of Anzick-1s genome, however, revealed the child was part of a line that was directly ancestral to 80 percent of all American native peoples, and close cousins to the remaining 20 percent.

In addition, analysis of the childs mitochondrial DNA indicated Anzick-1 belonged to whats known as the D4h3a haplogroup, or lineage. The finding is important and surprising, according to researchers because the D4h3a line is considered to be a founder lineage, belonging to the first people to arrive in the Americas. Although rare in most Native Americans in the U.S. and Canada today, D4h3a genes are found more commonly in native people of South America, far from the Montana cliff beneath which Anzick-1 was laid to rest.

Placing Anzick-1 in the D4h3a haplogroup suggests greater genetic complexity among Native Americans than previously believed, including an early divergence in genetic lineage 13,000 years ago or more. One theory had suggested that after crossing into North America from Siberia, one group of early Americans, with the D4h3a lineage, moved south along the Pacific coast and eventually, over thousands of years, to Central and South America. Other groups may have moved inland, east of the Rockies, as ice sheets retreated.

Finding Anzick-1s D4h3a lineage in central Montana casts doubt on that theory, though researchers were quick to caution that we shouldnt draw conclusions about migration patterns more than 10,000 years ago by comparing one ancient genome with that of modern people. Only the discovery and genetic sequencing of other remains as old as Anzick-1 will clarify how and when populations spread from the far northwest of the Americas.

Anzick-1 was estimated to be 12-18 months old at the time of his death; a cause of death has not been identified. He was covered in red ochre, a natural pigment, and apparently buried with several tools made of bone or stone in the style of the Clovis people. The Clovis people are generally believed to be the first wholly indigenous culture of North America, though there is archaeological evidence some of it contentious of an earlier human presence in the Americas.

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Earliest American Genome Proves Siberian Origins of Native Peoples