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 for GeoGenetics 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 of GeoGenetics. 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."