Native American populations descend from three key migrations

Jul 11, 2012

Scientists have found that Native American populations — from Canada to the southern tip of Chile — arose from at least three migrations, with the majority descended entirely from a single group of First American migrants that crossed over through Beringia, a land bridge between Asia and America that existed during the ice ages, more than 15,000 years ago.

By studying variations in Native American DNA sequences, the international team found that while most of the arose from the first migration, two subsequent migrations also made important genetic contributions. The paper is published in the journal Nature today.

"For years it has been contentious whether the settlement of the Americas occurred by means of a single or multiple migrations from Siberia," said Professor Andres Ruiz-Linares (UCL Genetics, Evolution and Environment), who coordinated the study. "But our research settles this debate: Native Americans do not stem from a single migration. Our study also begins to cast light on patterns of human dispersal within the Americas."

In the most comprehensive survey of genetic diversity in Native Americans so far, the team took data from 52 Native American and 17 Siberian groups, studying more than 300,000 specific DNA sequence variations called Single Nucleotide Polymorphisms to examine patterns of genetic similarities and differences between the groups.

The second and third migrations have left an impact only in Arctic populations that speak Eskimo-Aleut languages and in the Canadian Chipewyan who speak a Na-Dene language. However, even these populations have inherited most of their genome from the First American migration. Eskimo-Aleut speakers derive more than 50% of their DNA from First Americans, and the Chipewyan around 90%. This reflects the fact that these two later streams of Asian migration mixed with the First Americans they encountered after they arrived in North America.

"There are at least three deep lineages in Native American populations," said co-author David Reich, Professor of genetics at Harvard Medical School. "The Asian lineage leading to First Americans is the most anciently diverged, whereas the Asian lineages that contributed some of the DNA to Eskimo–Aleut speakers and the Na-Dene-speaking Chipewyan from Canada are more closely related to present-day East Asian populations."

The team also found that once in the Americas, people expanded southward along a route that hugged the coast with populations splitting off along the way. After divergence, there was little gene flow among Native American groups, especially in South America.

Two striking exceptions to this simple dispersal were also discovered. First, Central American Chibchan-speakers have ancestry from both North and South America, reflecting back-migration from South America and mixture of two widely separated strands of Native ancestry. Second, the Naukan and coastal Chukchi from north-eastern Siberia carry 'First American' DNA. Thus, Eskimo-Aleut speakers migrated back to Asia, bringing Native American genes.

The team's analysis was complicated by the influx into the hemisphere of European and African immigrants since 1492 and the 500 years of genetic mixing that followed. To address this, the authors developed methods that allowed them to focus on the sections of peoples' genomes that were of entirely Native American origin.

"The study of Native American populations is technically very challenging because of the widespread occurrence of European and African mixture in Native American groups," said Professor Ruiz-Linares.

"We developed a method to peel back this mixture to learn about the relationships among Native Americans before Europeans and Africans arrived," Professor Reich said, "allowing us to study the history of many more Native American populations than we could have done otherwise."

The assembly of samples from such a diverse range of populations was only possible through a collaboration of an international team of 64 researchers from the Americas (Argentina, Bolivia, Brazil, Canada, Chile, Colombia, Costa Rica, Guatemala, Mexico, Peru, Russia and the USA), Europe (England, France, Spain and Switzerland) and Russia.

Explore further: Automating the selection process for a genome assembler

More information: 'Reconstructing Native American population history' is published in the journal Nature on 11 July 2012. DOI: 10.1038/nature11258

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Telekinetic
1.4 / 5 (11) Jul 11, 2012
It would be interesting to hear the folklore of these migrations; Were they forced to leave by necessity, or were they nomadic by nature? Siberia is very harsh, so moving to warmer climes is understandable. Also, were there marauders before Attila or Genghis Khan that spurred mass migrations? And the return to Siberia is another big question mark thrown in to the mix. I can also see the Oriental {East Asian) features in Native Americans. What a journey that must've been!
ryggesogn2
1.5 / 5 (10) Jul 11, 2012
What about the Europeans that migrated to the east coast thousands of years ago?
Vendicar_Decarian
1 / 5 (4) Jul 12, 2012
Impossible, since they are Christians and for them the world is only 7,000 years old. The Dinosaurs wouldn't have allowed them to cross the ocean.

"What about the Europeans that migrated to the east coast thousands of years ago?" - RyggTard
Harlan
2 / 5 (4) Jul 12, 2012
Bull plucky.... how can we make sense of this when Charles C. Mann in his book titled "1491: New Revelations of the Americas Before Columbus" debunks this land bridge myth?!?!? I have a strong feeling these non-Native scientists that are so tied to this land bridge theory is because it is rooted in the their christian dogma with biblical text of the tower of Babel. Western science should really take up the interconnected relation between itself and christainity. The questions that Vine Deloria brings up in his writings would give them a good place to start this discussion.

As a First Nation person, this land bridge theory and its non-Native supports is very problematic for us. As it is used to justify the colonization of the first peoples on this because we too are then viewed as colonizers and therefore do not have rights to this land, then it became an issue of might make right.

Once agian, a response to Mann and Deloria is required!
Claudius
1.5 / 5 (8) Jul 12, 2012
What about the Europeans that migrated to the east coast thousands of years ago?


Good point. Since they filtered out "contamination" of the "Native American" genes by Europeans, they eliminated the possibility of what seems certain to have been a European migration tens of thousands of years ago. It does seem impossible to do a genetic analysis of this, though.
Pediopal
1.5 / 5 (8) Jul 12, 2012
It looks like somebody has drunk the Stanford/Bradley Kool-Aid. You do know they published the book because their peers would not even waste their time to review their theory dont you? Erich von Däniken is another authority on the origins of the Indians based on the wishin makes is so ideology and wrote many books so I suppose you believe him too. When a theory is so far out and debunked no one will even waste their time to comment on it (think scientist vs. creationism) then just write a book and publish it as science no problem.
LuckyBrandon
1.8 / 5 (10) Jul 12, 2012
@Harlan-by that logic, then anyone in Europe or pretty much anywhere else in the world also do not have rights to their land because thir ancestors colonized it during our species (or predecessor species) migration out of africa.
BUT, that's not really valid...when they finished their migration, they settled down in Europe or wherever. The NA/SA tribes just had a longer walk to get to their ultimate destination :) That is not an insult to the tribes, its a tribute to some major intestinal fortitude!
It's the same thing, just a longer timescale in my mind. Everyone on this planet is a colonizer....we just pay to do it nowadays....

But I'm pretty sure I saw somewhere some very solid evidence the lad bridge existed. 99% chance native's didn't evolve here in the americas, which means there HAS to be a method of transpot into the americas in the first place.
Telekinetic
1.4 / 5 (11) Jul 12, 2012
Bull plucky.... how can we make sense of this when Charles C. Mann in his book titled "1491: New Revelations of the Americas Before Columbus" debunks this land bridge myth?!?!? I have a strong feeling these non-Native scientists that are so tied to this land bridge theory is because it is rooted in the their christian dogma with biblical text of the tower of Babel. Western science should really take up the interconnected relation between itself and christainity.
As a First Nation person, this land bridge theory and its non-Native supports is very problematic for us.

Harlan:
The DNA sampling from various groups is legitimate scientific evidence. If you were in court with Barry Scheck, I suppose you could upend the reliability of DNA evidence like he did in the O.J. trial. In this case, now that the science has been refined since that time, it seems pretty solid. There is really little doubt that Native Americans are the earliest "settlers" in the Americas that we know of.
Telekinetic
1 / 5 (9) Jul 12, 2012
This is another type of proof- the language connection. This was written in 2008, making the physorg piece a bit stale.

http://news.natio...ink.html
LuckyBrandon
1 / 5 (7) Jul 23, 2012
This is another type of proof- the language connection. This was written in 2008, making the physorg piece a bit stale.

http://news.natio...ink.html


This only speaks to one branch of native languages (there are MANY). It seems to me that IF there was an ancient commonality, than the tribes would not have had great difficulty in communicating (this btw is not the case...the language variations are VERY different).
I would be SHOCKED if this applied to my lineage (Blackfoot; ie Algonquin language family), because its nothing like the lineage described in the article you referenced. This would make sense for tribes that originated IN Siberia (or around the area), but not for tribes that come from eastern asia (which btw is the large majority afaik).