Ancient DNA Studies Show the Paleo-Indians’ Deep Roots in Both North and South America

Remnants of the Anzick child could only be found in 1968 in Montana, USA, and more so, his genetic basis came out only in 2014. The genetic analysis could establish the fact that the Anzick child was part of the population that formed the North, Central and South American populations. Nevertheless, the genetic information of the Native Americans is still sparse, and thus, telling how the ancient peoples spread across the continents has been a difficult task. Recently published two papers, one in Science and another in Cell have provided much input to the genetic record of the Americas.

Both of the papers come to the conclusion that people related to the Anzick child, part of Clovis culture, were spreading quickly across North and South America as old as 13,000 years ago.

The studies include data of 64 newly sequenced ancient DNA samples from Alaska to Patagonia. The data spans a genetic history of more than 10,000 years. Prior to these studies, the sequenced DNA consisted only six genomes older than 6000 years only.

University of Copenhagen evolutionary geneticist Eske Willerslev – one that led the team that published in Science – worked closely with the Fallon Paiute-Shoshone tribe in Nevada. In their effort to get access to some of the new samples, the team had to face tough time to convince the tribe. The team vowed that they would work only with the permission of the tribe, and only then the tribe agreed to cooperate. The tribe had been fighting for the repatriation of 10,700 years’ remains found in Nevada’s Spirit cave. They believed that the new genetic study would strengthen their case for repatriation, and cooperated.

Willerslev found that the remains from the spirit cave were very close to the living Native Americans. This strengthened the Fallon Paiute-Shoshone tribe’s claim to the bones from where the DNA were extracted and returned to them in 2016 and reburied. Willerslev added extra 14 new whole genomes to the Spirit Cave data collected from various sites from Alaska to Chile that dates back to 10,700 to 500 years.

The team that published in Cell was led by Harvard Medical School, Boston’s population geneticist David Reich. Their data contained the DNA analysis from 49 new samples from Central and South America dating back to 10,900 to 700 years. This data set is even bigger than the one taken by Willerslev’s team.

The findings strongly dispel suggestions that early populations had a different ancestral history from today’s Native Americans.

How ancient Americans moved across the continent some 13,000 years ago has been captured in these studies, and they are able to give an unprecedented view of the ancient Americans’ movement. It had been thought from earlier genetic studies that the ancestors of Native Americans split from Siberians and East Asians some 25,000 years back. They entered Beringia, the place that bridged the Russian Far East and North America. Beringia is now an almost drowned landmass. Eventually, some populations stayed isolated in Beringia and Willerslev’s team could found the DNA sample of such an old Beringian, 9,000 years old remains from Alaska’s Seward Peninsula. Meanwhile, the other part of the population headed Southward, and at some point, they further spilt into two groups, namely the Southern Native Americans and Northern Native Americans. These two groups continue to populate the two American continents.

Willerslev’s team detected Anzick-related ancestry in both the samples— one from the spirit cave, and the other from Lagoa Santa in Brazil. Reich’s team found a more close relationship between Anzick and 9300-10900 year old sample that was collected from Chile, Brazil and Belize.