Native Americans can trace their origins to a remote mountainous region of Siberia, new genetic research has shown.
A University of Pennsylvania-led team of anthropologists says Native Americans started mograting away from the Altai region - which lies at the intersection of what is today Russia, Mongolia, China and Kazakhstan - roughly 20-25,000 years ago.
They carried their Asian genetic lineages up into the far reaches of Siberia and eventually across the then-exposed Bering land mass into the Americas.
The study analyzed the genetics of individuals living in Russia’s Altai Republic to identify markers that might link them to Native Americans. They assessed the Altai samples for markers in mitochondrial DNA, which is maternally inherited, and in Y chromosome DNA, which is passed from fathers to sons.
They also compared the samples with others from individuals in southern Siberia, Central Asia, Mongolia, East Asia and a variety of American indigenous groups. Because of the large number of gene markers examined, the findings have a high degree of precision, they say.
Looking at the Y chromosome DNA, the researchers found a unique mutation shared by Native Americans and southern Altaians in the lineage known as Q.
"This is also true from the mitochondrial side," says Theodore Schurr, an associate professor in Penn’s Department of Anthropology.
"We find forms of haplogroups C and D in southern Altaians and D in northern Altaians that look like some of the founder types that arose in North America, although the northern Altaians appeared more distantly related to Native Americans."
Calculating how long the mutations took to arise, the team estimates that the Altaian and Native American lineages diverged 13,000 to 14,000 years ago, a timing that fits with the idea of people moving into the Americas from Siberia between 15,000 and 20,000 years ago.
Next, the team hopes to continue to use molecular genetic techniques to trace the movement of peoples within Asia and on into the Americas. They may also try to find links between genetic variations and adaptive physiological responses - something that could be helpful in biomedical research.