DNA uncovers mystery migration to the Americas

[Skywizard]

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Modern day native people in Brazil have traces of Australasian DNA, raising new questions
about how and when the first Americans arrived.


Two separate genetic analyses have found evidence for a surprising genetic link between
the native populations of the Americas and Oceania.

The DNA of some native Amazonians shows significant similarity to indigenous inhabitants of Australia and Melanesia.

The two research groups, however, offer contrasting interpretations of how the Americas were first peopled.

The studies have been published in the journals Science and Nature.

There is agreement that the first people to populate the Americas came though Siberia - along a land bridge connecting it with Europe and Asia. But just where these people came from and when they arrived has been a matter of some debate.

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Could this have been the route of the first Americans?

By analysing the DNA of modern native Americans and ancient human remains, the group writing in Science concluded that all present-day Native Americans arrived in a single migration no earlier than 23,000 years ago.

Then, they argue, Native Americans split into two branches around 13,000 years ago: one that is now dispersed across North and South America while the other is restricted to North America.

"Our paper shows that the simplest possible model seems by and large to be true, with [that] one notable exception," Prof Rasmus Nielsen from the University of California, Berkley, told BBC News.

"[So] the fanciful ideas that somehow the Americas were populated by people coming from Europe and all kinds of other places are wrong."

The analysis also rules out a theory, favoured by some, of a staggered migration from Siberia: the first more than 30,000 years ago which was stemmed for 15,000 years because of ice blocking the route, and then a second wave when the route was clear.

But, in agreement with the study in Nature, Prof Nielsen's team does report traces of "Australo-Melanesian" ancestry in certain populations, including those of the Aleutian islands (off Alaska) and the Surui people of the Brazilian Amazon.

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This map from the Nature paper highlights the similarity between indigenous
Amazonians and Australasians

Prof David Reich, from Harvard Medical School, led the separate study in Nature. He told the BBC that "both studies show that there have been multiple pulses of migration into the Americas".

According to Prof Reich, the discovery of Oceanian ancestry among certain Native American groups indicates that the Americas were peopled by a more diverse set of populations than previously accepted.

"The simplest possible model never predicted an affinity between Amazonians today and Australasians," he said.

"This suggests that there is an ancestral population that crossed into the Americas that is different from the population that gave rise to the great majority of Americans. And that was a great surprise," he said.

Prof Reich believes that the most plausible explanation is that there was a separate migration from Australasia, possibly around 15,000 years ago. This group, he speculates, was probably more widely dispersed across North America but was eventually pushed out by other native American groups.

Prof Nielsen, however, has a different interpretation. He believes that the traces of Australasian DNA stem from a later migration, around 8,000 years ago, which progressed around the Pacific coast.



Source: http://www.bbc.com/news/science-environment-33612869



peace...

[Delight]

According to Prof Reich, the discovery of Oceanian ancestry among certain Native American groups indicates that the Americas were peopled by a more diverse set of populations than previously accepted.

Thanks for posting.

Here is a really interesting website "Polynesian Pathways" (http://www.polynesian-prehistory.com/) written by Peter Marsh. He reports that the latest movement of Polynesians was about 2000 years ago. In investigating the story he also realized that the true history of Polynesians was also the history of ignored global civilizations (Atlantis and others). The following videos and quotes are all from Peter Marsh.

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His synthesis is a very significant contribution to the chronology of human development and periodic diaspora.


The general consensus of geneticists is that the present species of humans - Homo Sapiens began in Africa 150,000 years ago. This has been spelled out fairly clearly by Bryan Sykes in his book 'The Seven Daughters of Eve'. Despite this, we must not forget that there have been many species of humans or bipetal hominids with opposing thumbs that have populated the world before us. The Leaky family did extensive studies in Africa on a 3 million year old bipetal hominid they called Lucy. Recently a 7 million year old bipetal hominid (human) skull was unearthed in Chad by professor Michel Brunet of the University of Poitiers in France. There is also a variety of Homo erectus, Java man, Peking man and Australopithecus, Giganthropus to name a few, some were less than a metre tall others were over four metres tall. With their opposing thumbs, they were all capable of using tools such as hammers, axes and spears. Large 20kg axe heads have been found associated with 60cm footprints in New South Wales, which indicates the size and technological development of these people 800,000 years ago. The tools are thought to have been made by 'Java Man', as similar aged tools have been found in Indonesia. Just as we see a great range of body sizes in the canine species, from Great Danes to Chihuahuas, it is only logical to assume there has been a similar variation with humans. When Sabre toothed tigers, Diprotodons, Woolly Mammoths and other large and powerful beasts dominated the environment, large and powerful people would have had a better chance of survival against these predators. On the other hand, smaller people would have had a better chance of survival after a natural catastrophe, such as a comet impact, where dust was thrown up into the atmosphere, dimming the earth for a few years, causing cooling, massive droughts and a scarcity of food. The locality of impacts, eruptions and tsunamis would have played a big part in who the survivors were. Rather than 'survival of the fittest', chance, had a much bigger part to play in determining who the survivors were.

Proof of the diversity in humans can be seen from recent studies in Indonesia where they unearthed 'the Hobbit' a very small human, from about 13,000 years ago. The skeleton was about one metre tall.

Skeletons at Kow Swamp in New South Wales shows that Homo Erectus was alive and well in Australia only 10,000 years ago. Clear evidence that there were many breeds of humans right up to less than 10,000 years ago.

[Ellisa]

Kow swamp and Lake Mungo dating of finds has been pushed back to 40-50,000 years ago, and possibly more. This research is still on-going in Australia and is giving surprising results, for example it was only recently that Aboriginals were discovered to have Denisovian (spelling!) DNA! It looks as though there were different waves of immigration from many other places--- but where? that's what is unknown. I have lived in Australia for 50+ years and when I come here it was accepted that the Aborigines had been here for, at the most, 10,000 years! At the time, much to everyone's surprise, a new group of Aboriginal people had just been discovered living in the 'inhospitable' interior of the country.

There is a lot to learn about early human history, and it seems that humans and humanoids have been in many places for much longer than expected, maybe 800,000 years ago!

Thanks for such an interesting post Skywizard.