Study: Europeans had common ancestors
BERLIN — Europeans appear to be more closely related than previously thought.
Scientists who compared DNA samples from people in different parts of the continent found that most had common ancestors living 1,000 years ago.
The results confirm decade-old mathematical models but will nevertheless be a surprise to Europeans accustomed to thinking of ancient nations composed of distinct ethnic groups such as “Germans,” “Irish” or “Serbs.”
“What's remarkable about this is how closely everyone is related to each other,” said Graham Coop of the University of California, Davis, who co-wrote the study published on Tuesday in the journal PLoS Biology.
Coop and fellow author Peter Ralph of the University of Southern California used a database containing more than 2,250 genetic samples to look for shared DNA segments that would point to shared relatives.
While the number of common genetic ancestors is greater the closer people are to each other, even individuals living 2,000 miles apart had identical sections of DNA that can be traced back roughly to the Middle Ages.
The findings indicate that there was a steady flow of genetic material between countries as far apart as Turkey and Britain, or Poland and Portugal, even after the great population movements of the first millennium A.D. such as the Saxon and Viking invasions of Britain, and the westward drive of the Huns and Slavic peoples.
The study found subtle regional variations. For reasons still unclear, Italians and Spaniards appear to be less closely related than most Europeans to people elsewhere on the continent.
“The analysis is pretty convincing. It comes partly from the enormous number of ancestors each one of us have,” said Mark A. Jobling, a professor of genetics at the University of Leicester, England, who wasn't involved in the study.
Because the number of ancestors each person roughly doubles with each generation, “we don't have to go too far back to find someone who features in all of our family trees,” he said.
Jobling cited a scientific paper published in 2004 that went so far as to predict that every person on the planet shares ancestors who lived just 4,000 years ago.
Coop and Ralph said the findings might change the way Europeans think about their neighbors on a continent that has had its fair share of struggle and strife.
“The basic idea that we're all related much more recently than one might think has been around for a while, but it is not widely appreciated, and still quite surprising to many people,” they said “The fact that we share all our ancestors from a time period where we recognize various ethnic identities also points at how we are like a family — we have our differences, but are all closely related.”