European Ancestry Traced
By Jerilyn WatsonThis is the VOA Special English SCIENCE REPORT.
A new study shows that Europeans may be related to ancient people who came from Central Asia and the Middle East. The study suggests that these ancestors of Europeans arrived on the continent in three major groups. The researchers believe this happened during twenty-five-thousand years.
Ornella Semino of Italy and Peter Underhill of the United States led European and American scientists in the research. Their study appears in the journal Science. They examined the Y chromosomes in blood from more than one-thousand men in Europe. Men have one Y chromosome in each cell. The Y chromosome contains genes from the father. This makes it useful for studying genetic history.
The Y chromosome does not change much from father to son. But a few changes do take place. These differences can tell genetic experts which people are most closely related. The experts also can estimate how long ago the changes appeared. This makes it possible to decide when populations moved to different areas. Stanford University scientist Giuseppe Passarino took part in the study. He says the earliest ancestors of many current Europeans moved from Central Asia to western and southern Europe about thirty-five-thousand years ago.
The report also says a second group of people came from the Middle East about twenty-two-thousand years ago. They settled in central and eastern Europe.
The scientists say large areas of ice in Europe kept the two areas separate. The earlier Central Asian arrivals apparently settled in what is now Spain. The later Middle Eastern people settled in the Balkans and Ukraine.
The study says the two groups expanded their living space and began to live together when the ice melted. That happened about sixteen-thousand years ago. About eighty-percent of modern Europeans received genes from these early people.
A third group of people came to Europe from the Middle East about nine-thousand years ago. These people provide about twenty percent of modern European genes.
Other scientists say the suggested timing of the movements of populations may not be correct. They also say chromosome studies should be only one of the many ways to investigate human history.
This VOA Special English SCIENCE REPORT was written by Jerilyn Watson.