The exact process by which humanity introduced itself to the Americas has always been controversial. While there's general agreement on the most important migration—across the Bering land bridge at the end of the last ice age—there's a lot of arguing over the details. Now, two new papers clarify some of the bigger picture but also introduce a new wrinkle: there's DNA from the distant Pacific floating around in the genomes of Native Americans. And the two groups disagree about how it got there.
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The Athabascans and Aleutian islanders also have a rather unexpected contribution from Australo-Melanesians, the natives of Australia, New Guinea, and the Andaman Islands. That, this study found, was absent in populations farther south.Not so, says the study that focused on South American groups. Here, a strong signal from Australo-Melanesians was present in a number of Amazonian tribes; weaker affinities are scattered through South and Central America. At the same time, there are other groups in this region with no affinity to Australo-Melanesians.
It will be interesting to see if migration paths can be reconstructed as DNA from more locations in the Pacific can be sequenced.
(Score: 4, Funny) by Anne Nonymous on Wednesday July 22 2015, @04:01PM
> there's DNA from the distant Pacific floating around... two groups disagree about how it got there.
My theory: G'day. Mate?
(Score: 2) by Thexalon on Wednesday July 22 2015, @08:23PM
See, my hypothesis relates to some visitors engaging in a practice an Aussie I met on a train called "wombating": Eats, roots, and leaves.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 1, Interesting) by Anonymous Coward on Wednesday July 22 2015, @04:38PM
the peoples that came across the bering land bridge didn't ALL go across the bering land bridge. those people had the 'australian gene' before they ever went to australia.
some ancient group of people dispersed themselves by land to the north and by sea to the west and south. some went across the land bridge. some scattered out among the south pacific islands.
the more interesting and big mystery to me, then, is what caused this massive population to scatter? were they fleeing some great natural disaster?
(Score: 0) by Anonymous Coward on Wednesday July 22 2015, @06:52PM
No doubt it was the 1% of their time fleeing high taxes.
(Score: -1, Troll) by Anonymous Coward on Wednesday July 22 2015, @07:12PM
yeah, just 1% that went on to populate the half the world. get your head out your ass.
(Score: 0) by Anonymous Coward on Wednesday July 22 2015, @09:57PM
Not likely. That doesn't fit what is known from genetic studies. Australia was peopled a long time ago, before the folks who populated northern Asia arrived.
I still think there's room for an early trans-Pacific migration route. It's just hard to fit into the combination of the archaeological record and the genetic info that's available. There is evidence of a late trans-Pacific migration, but not much for an early one.
(Score: 1, Touché) by Anonymous Coward on Wednesday July 22 2015, @10:11PM
So, if they came over the Bering land bridge, why are they clustered in South America, rather than evenly dispersed across the New World?
(Score: 3, Interesting) by Runaway1956 on Wednesday July 22 2015, @04:47PM
I thought it was pretty well established that the Americas were settled in multiple waves. I'm not going looking for links today, but I seem to recall that some select American tribes could be traced back to western Europe, many other to southern Asia, and a good number of others to Polynesian/South Pacific. What's more, successive waves across the Bering straits originated from different places.
Considering how widely traveled the Polynesians were, it should surprise no one that they might have carried genes from around the world. What else would you expect from island hoppers? Many of them went out - and never came back. Others went out on the sea, and didn't come back for years. You can bet they were donating DNA samples during those years. Some of those who never did come back probably did the same.
One thing is for certain: South Pacific sailors a few thousand years ago never read any European charts with "Here there be dragon" warnings on them.
(Score: 2, Informative) by ese002 on Wednesday July 22 2015, @07:33PM
Considering how widely traveled the Polynesians were, it should surprise no one that they might have carried genes from around the world. What else would you expect from island hoppers? Many of them went out - and never came back. Others went out on the sea, and didn't come back for years. You can bet they were donating DNA samples during those years. Some of those who never did come back probably did the same.
It isn't too hard to come up with a late arrival theory. The Orang Asli are a Australo-Melanesian people from the Malay peninsula. So quite trivially some or the Polynesians would be carrying Australo-Melanesian genes when they started heading East. Further, we know that the Polynesians reached the Americas. Sweet Potatoes have been a staple food in Polynesians culture since before contact with Europeans. But sweet potatoes only grow natively in Central and South America.
Early arrival would mean people carrying Australo-Melanesian genes crossed over the Bearing land bridge. That seems probable though I haven't heard any suggestion that an actual Australo-Melanesian people crossed that way.
(Score: 2) by arslan on Thursday July 23 2015, @04:16AM
Tony Abbot, and most Aussie politicians from the 2 major camps (sounds like the U.S. doesn't it?), will ask "How much?" if an American politician says "Get bent!".