A genetic analysis has shown that Northern European people are a mixture of two very different ancestral populations - and one of these populations is related to Native Americans.
The discovery applies to the British, Scandinavians, French and some Eastern Europeans, and explains some genetic similarities among what would otherwise seem to be very divergent groups.
"There is a genetic link between the paleolithic population of Europe and modern Native Americans," says Nick Patterson of the Genetic Society of America.
"The evidence is that the population that crossed the Bering Strait from Siberia into the Americas more than 15,000 years ago was likely related to the ancient population of Europe."
By examining DNA, his team found that one of these ancestral populations was the first farming population of Europe, whose DNA lives on today in relatively unmixed form in Sardinians and the people of the Basque Country, as well as the Druze population in the Middle East.
The other ancestral population is likely to have been the initial hunter-gathering population of Europe - very different from the farmers. Today, the hunter-gathering ancestral population of Europe seems to be most in evidence in the people of far Northeastern Siberia and Native Americans.
"This relationship between humans separated by the Atlantic Ocean reveals surprising features of the migration patterns of our ancestors, and reinforces the truth that all humans are closely related," says Mark Johnston, editor-in-chief of Genetics, where the report appears.