DNA research revealed genetic markers linking people living in the Russian republic of Altai, southern Siberia, with indigenous populations in North America.

A study of the mutations indicated a lineage shift between 13,000 and 14,000 years ago - when people are thought to have walked across the ice from Russia to America.

This roughly coincides with the period when humans from Siberia are thought to have crossed what is now the Bering strait and entered America.

'Altai is a key area because it's a place where people have been coming and going for thousands and thousands of years,' said Dr Theodore Schurr, from the University of Pennsylvania in the US.

Among the people who may have emerged from the Altai region are the predecessors of the first Native Americans. Roughly 20-25,000 years ago, these prehistoric humans carried their Asian genetic lineages up into the far reaches of Siberia and eventually across the then-exposed Bering land mass into the Americas.

Dr Schurr's team checked Altai DNA samples for markers in mitochondrial DNA which is always passed on by mothers, and Y chromosome DNA which sons inherit from their fathers. Because of the large number of gene markers examined, the findings have a high degree of precision.

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. Mitochondrial DNA is found in tiny rod-like 'powerplants' in cells that generate energy. Both kinds of DNA showed links between Altaians and Native Americans. In the Y chromosome DNA, the researchers found a unique mutation shared by Native Americans and people from southern Altai, Daily Mail reported quoting the American Journal of Human Genetics.