Monday, December 9, 2013

New Evidence Shows Native Americans' Origins are Older than Previously Thought

This pretty well nails it.  We have been posting on this likelihood for a long time wondering just when the DNA work would lock it down.  This is it.

Siberian stock was largely congruent with European stock and its natural extension into the Americas.  That likely held true for the several thousands of years prior to the Pleistocene Nonconformity of 12900 BP.  After the Ice Age life way ended so abruptly, adjacent populations moved northward into these new territories and these were mostly East Asian associated with the types out of the highlands of the Himalayas.

They likely made the crossings by sea along the coasts.

There will be plenty more DNA surprises but we now have blocked out the shape of the migrations.  This includes our recent report on DNA in Mexico from 24000 BP that is clearly European.

New evidence shows Native Americans' origins are older than previously thought

The new evidence shows that pre-Columbian American Indians had European ancestors.

A genetic analysis of human remains from 24,000 years ago has given scientists an important bit of evidence in resolving remaining questions over the origins of pre-Columbian Americans. A genome sequence of the ancient Siberian by a team led by the Center forGeoGenetics of the Natural History Museum at the University of Copenhagen shows signatures that relate to peoples of western Eurasia (in other words: Europe) and also to modern Native Americans. The breakthrough reveals much about the genetic composition of human beings living ages ago on the Eurasia landmass.  It is believed, as a result of the study, that pre-Columbian or First Americans have ancestors who were a mixture of at least two populations. One of these is related to modern East Asians such the Koreans and Japanese, and the other to modern people of western Eurasia. This may explain why Native Americans show mitochondrial lineage X in their genetic make up.

"The result came as a complete surprise to us. Who would have thought that present-day Native Americans, who we learned in school derive from East Asians, share recent evolutionary history with contemporary western Eurasians?” said Eske Willerslev ofGeoGenetics. Of the study, Kelly Graf from Texas A&M University said "Our findings are significant at two levels. First, it shows that Upper Paleolithic Siberians came from a cosmopolitan population of early modern humans that spread out of Africa to Europe and Central and South Asia. Second, Paleoindian skeletons with phenotypic traits atypical of modern-day Native Americans can be explained as having a direct historical connection to Upper Paleolithic Siberia."

 It was at the Russia’s Hermitage Museum in St. Petersburg that researched conducted samples in 2009 of the remains of a teenaged individual (MA-1) from Mal’ta – a site in the south central region of Siberia where artifacts from the Upper Palaeolithic age have been found. This individual has been dated to about 24,000 years ago. “Representing the oldest anatomically modern human genome reported thus far, the MA-1 individual has provided us with a unique window into the genetic landscape of Siberia some 24,000 years ago", said Dr. Maanasa Raghavan.  According to Raghavan, who works at GeoGenetics, the sampled individual shows hardly any genetic affinity to the people now living in his place of origin: southern Siberia.

The genetic evidence indicates that MA-1 is actually related to modern western Eurasians. The subject’s genome provides evidence, therefore, that peoples related to modern western Eurasians ranged much wider range than previously thought. 

However, the MA-1 genome, most importantly, shows its relationship to Native Americans living today. Interestingly, while MA-1 is closely related to Native Americans living today, there is little affinity to East Asians who are believed to be close relatives to Native Americans.

The team led by Ragavan has concluded that the genetic affinity between MA-1 and Native Americans has an admixture of ancestry evidenced by MA-1, thus explaining between 14-38% of modern Native Americans, with the remainder of the ancestry being derived from East Asians. The study holds that two different Eurasian peoples contributed to the gene pool of the First Americans. One of these is to East Asians of the present day, while the other stems from an Upper Palaeolithic population from Siberia that is related to modern western Eurasians.

The team also offered results from examining a second south-central Siberian from the Afontova Gora-2 site.  This individual lived approximately 17,000 years ago, which was at a time that followed the so-called Last Glacial Maximum (ca. 26,000-19,000 years ago), when glaciers reached their maximum extent in Eurasia and North Ameirca.  The study showed that this second individual showed genomic signatures that are similar to MA-1, and thus has close affinity to western Eurasians and Native Americans living today but none to modern East Asians. This means there was a continuity of genetic affinity throughout the glacial age and must be taken into consideration when researchers and anthropologists look into the issue of human migration into early America approximately 15,000 years ago.

In summing up the findings, Dr. Pontus Skoglund from Uppsala University explained,  "Most scientists have believed that Native American lineages go back about 14,000 years ago, when the first people crossed Beringia into the New World. Our results provide direct evidence that some of the ancestry that characterizes Native Americans is at least 10,000 years older than that, and was already present in Siberia before the last Ice Age."

Ancient, modern DNA tell story of first humans in the Americas

University of Illinois anthropology professor Ripan Malhi looks to DNA to tell the story of how ancient humans first came to the Americas and what happened to them once they were here.

 He will share some of his findings at the meeting, "Ancient DNA: The First Three Decades," at The Royal Society in London on Nov. 18 and 19.

Malhi, an affiliate of the Institute for Genomic Biology at Illinois, will describe his collaborative approach, which includes working with present-day Native Americans on studies of their genetic history.

He and a group of collaborators from the Tsimshian Nation on the northwest coast of British Columbia, for example, recently found a direct ancestral link between ancient human remains in the Prince Rupert Island area and the native peoples living in the region today. That study looked at changes in the mitochondrial genome, which children inherit only from their mothers.

Other studies from Malhi's lab
 analyze changes in the Y chromosome or the protein-coding regions of the genome.

"The best opportunity to infer the evolutionary history of Native Americans and to assess the effects of European colonization is to analyze genomes of ancient Native Americans and those of their living descendants," Malhi said.

"I think what makes my lab unique is that we focus not only on the initial peopling of the Americas but also what happened after the initial peopling. How did these groups move to new environments and adapt to their local settings over 15,000 years?"

While continuing his work in British Columbia, Malhi also is setting up study sites in California, Guatemala, Mexico and Illinois.

"What's interesting about the northwest coast and California is that these communities were complex hunter-gatherer societies, whereas in Mexico and Guatemala, it's more communities that transitioned to farming and then experienced the effects of European colonization," he said.

Genomic studies can fill in the blanks on studies that seek to tell the story of life in the Americas before and after European colonization, Malhi said. Researchers may draw the wrong conclusions about human history when looking only at artifacts and language, he said.

University of Illinois at Urbana-Champaign
 [November 18, 2013]

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