Amazonians share an unexpected genetic link with Asian islanders,

[Ichingcarpenter]

Skoglund’s discovery — which is published online on 21 July in Nature2 — was that members of two Amazonian groups, the Suruí and the Karitiana, are more closely related to Papua New Guineans and Aboriginal Australians than other Native Americans are to these Australasian groups. The team confirmed the finding with several statistical methods used to untangle genetic ancestry, as well as additional genomes from Amazonians and Papuans. “We spent a lot of time being sceptical and incredulous about the finding and trying to make it go away, but it just got stronger,” says Reich.

Their explanation is that distant ancestors of Australasians also crossed the Bering land bridge, only to be replaced by the First Americans in most of North and South America. Other genetic evidence suggests that modern-day Australasians descend from humans who once lived more widely across Asia. “We think this is an ancestry that no longer exists in Asia, which crossed Beringia at some point, but has been overwritten by later events,” Reich says. The team calls this ghost population “Population Y”, after the word for ancestor, Ypykuéra, in the languages spoken by the Suruí and Karitiana. They contend that Population Y reached the Americas either before or around the same time as the First Americans, more than 15,000 years ago.



http://www.nature.com/news/ghost-population-hints-at-long-lost-migration-to-the-americas-1.18029?WT.mc_id=TWT_NatureNews

Timing dispute

[Ichingcarpenter]

1. I'm not buying they crossed the land bridge when

this gene is not found in North america.

[Yo_Mama]

2. It does seem to be in Aleutian groups

As part of a study tracing the timing of humans’ migration across the Bering land bridge, Eske Willerslev, an evolutionary geneticist at the Natural History Museum of Denmark in Copenhagen, and his colleagues also noticed the link. But they contend that Australasian DNA reached the Americas less than 9,000 years ago. They discovered traces of Australasian ancestry in contemporary Aleutian islanders living off the coast of Alaska and propose that ancient Aleutians introduced the DNA into other Native American groups after the islands were first settled. Their study is published in Science1.

That's a different study which separately found a similar kinship, but in a different group.

Studies are continuing.

My guess is that this is probably a boat faring culture, which would explain the wide dispersion. Also it's evident that Native American DNA is under sampled to represent true diversity in the population.

The earlier dating is probably better.

[Yo_Mama]

3. You might be interested in this separate article

http://www.nytimes.com/2011/09/23/science/23aborigines.html?_r=0

The Aborigine occupation of Australia presents a series of puzzles, starting with the nature of their stone tools. The early stone tools found in Australia are much simpler than the Upper Paleolithic tools that appear in Europe at the same era. “I don’t understand why they looked so primitive,” said Richard Klein, a paleoanthropologist at Stanford University.

Primitive as the tools may be, the first inhabitants of Australia must have possessed advanced boat-building technology to cross from the nearest point in Asia to Sahul, the ancient continent that included Australia, New Guinea and Tasmania until the rise of sea level that occurred at the end of the last ice age, 10,000 years ago. But there is no archaeological evidence for boats, Dr. Klein said.

[Ichingcarpenter]

4. Yes and here is another article of new discoverys in South America

Which hints at a world wide boat culture or raft culture from Africa and also ancient Polynesia to south america.


http://www.nytimes.com/2014/03/28/world/americas/discoveries-challenge-beliefs-on-humans-arrival-in-the-americas.html

[Judi Lynn]

5. Thank you. n/t