DNA experts have rocked the anthropological world by isolating the genome of a young boy found buried at Mal’ta near Lake Baikal in eastern Siberia some 24,000 years ago. A team led by Dr. Eske Willersley of the University of Copenhagen discovered that the boy’s DNA matches that of Western Europeans. His theory, that during the last Ice Age, Europeans traveled far further east across Eurasia than had previously been thought. There are no tissue samples of the Mal’ta boy’s skin or hair, but his genes show clearly that he had brown hair, brown eyes and freckled skin. His DNA also matches a 25 percent proportion of the DNA still carried by living Native Americans. It now seems that the first arrivals in the Americas, assumed to have descended from a Siberian Asian background are actually a mixture between nomadic Western Europeans and East Asians.
The Mal’ta boy was three or four-years-old and buried under a stone slab wearing an ivory diadem, a bead necklace and a bird-shaped pendant. 30 Venus figurines were also found. The clear production of a kind only produced by the Upper Paleolithic cultures of Europe. These remains had been excavated by a separate group of Soviet-era archaeologists over a 20-year period ending in 1958 and stored in a St. Petersburg museum for more than 50 years. An expert in analyzing ancient DNA, Willersley extracted DNA off bone taken from the child’s upper arm. He found that the boy’s mitochondrial DNA belonged to the lineage known as U, commonly found among humans who entered Europe about 44,000 years ago. The separate lineages found among Native Americans are those designated A, B, C, D and X, so the U lineage was possibly a case of contamination of the bone by the archaeologists or museum curators who had handled it, a common problem with ancient DNA projects. The study was then reexamined vis-a-vis contamination every which scientific way.
Beyond analyzing the nuclear genome of the Mal’ta boy’s corpse, Willersley isolated the genome from a second Siberian grave site of an adult who died 17,000 years ago, finding the same DNA markers. Taken together, the two genomes clearly indicated that descendants of the humans who entered Europe walked east all the way to Siberia during the extremely cold period 20,000 years ago, the Last Glacial Maximum.
The Mal’ta boy’s genome, however, showed no East Asian match. Consequently, Dr. Willerslev believes that the ancestors of Native Americans had long since separated from the East Asian population at the point they interbred with the people of the Mal’ta culture This admixed population then crossed over the Beringian land bridge which bridged Siberia and Alaska to become the Native American population. “We estimate that 14 to 38 percent of Native American ancestry may originate through gene flow from this ancient population,” Willersley wrote in an article published in the journal, Nature.
This European contribution to Native American ancestry explains two conundrums concerning origin. One is that many ancient Native American skulls, including that of the well-known Kennewick man, look very different to those of the present day population. Considering the five mitochondrial DNA lineages found in Native Americans, the lineage known as X, also occurs in Europeans, Willersley’s logical explanation is that Europeans somehow crossed the Atlantic 20,000 years ago in small boats joining with the Native Americans from Siberia. Therefore, European bearers of the X lineage migrated across Siberia with the ancestors of the Mal’ta culture and joined them in their trek across the Beringian land bridge. What still goes unexplained is that the Mal’ta people did not pass on their mitochondrial DNA, as the U lineage is unknown among Native Americans. With mitochondrial DNA passed down only through the female line, the population ancestral to Native Americans must, it seems, have been formed by men of the Mal’ta culture, who acquired East Asian wives. There is also the much-disputed question as to exactly when the Americas were first settled. The newer genomes point archeologists past the Clovis culture from 13,000 years ago to an even earlier date.
