DNA study traces ancient ancestry of Europeans

Xxxx Xxxxx Xxxxxx xxxxxxxx at xxxxxxxxxxx.xxx
Mon Nov 13 14:19:53 MST 2000



Recent news from genetics--Xxxx

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http://edition.cnn.com/2000/NATURE/11/10/ancient.europeans.ap/

DNA study traces ancient ancestry of Europeans

November 10, 2000
Web posted at: 2:08 PM EST (1908 GMT)

WASHINGTON (AP) -- Four out of five men in Europe share a common male
ancestor who lived as a hunter on a wild continent some 40,000 years
ago, researchers say.

In a study appearing Friday in the journal Science, researchers say an
analysis of a pattern found in the Y chromosome taken from 1,007 men
from 25 places in Europe shows that about 80 percent of Europeans arose
from the Paleolithic people who first migrated to Europe.

Peter A. Underhill, a senior researcher at the Stanford Genome
Technology Center in Palo Alto, California, and co-author of the study,
said the research supports conclusions from archaeological, linguistic
and other DNA evidence about the settlement of Europe by ancient
peoples.

"When we can get different lines of evidence that tell the same story,
then we feel we are telling the true history of the species," said
Underhill.

Underhill said the researchers used the Y chromosome in the study
because its rare changes establish a pattern that can be traced back
hundreds of generations, thus helping to plot the movement of ancient
humans.

 Y chromosome used to trace ancestry

 The Y chromosome is inherited only by sons from their fathers. When
sperm carrying the Y chromosome fertilizes an egg it directs the
resulting baby to be a male. An X chromosome from the father allows a
fertilized egg to be female.

The Y chromosome has about 60 million DNA base pairs. Changes in those
base pairs happen infrequently, said Underhill, but they occur often
enough to establish patterns that can be used to trace the ancestry of
people.

He said researchers looking at the 1,007 chromosome samples from Europe
identified 22 specific markers that formed a specific pattern.

Underhill said the researchers found that about 80 percent of all
European males shared a single pattern, suggesting they had a common
ancestor thousands of generations ago.

The basic pattern had some changes that apparently developed among
people who once shared a common ancestor and then were isolated for many
generations, Underhill said.

This scenario, he said, supports other studies about the Paleolithic
European groups. Those studies suggest that a primitive, stone-age human
came to Europe, probably from Central Asia and the Middle East, in two
waves of migration beginning about 40,000 years ago. Their numbers were
small and they lived by hunting animals and gathering plant food. They
used crudely sharpened stones and fire.

Neolithic people brought the chromosome to Europe

About 24,000 years ago, the last ice age began, with mountain-sized
glaciers moving across most of Europe. Underhill said the Paleolithic
Europeans retreated before the ice, finding refuge for hundreds of
generations in three areas: what is now Spain, the Balkans and Ukraine.

 When the glaciers melted, about 16,000 years ago, the Paleolithic
tribes resettled the rest of Europe. Y chromosome mutations occurred
among people in each of the ice age refuges, said Underhill. He said the
research shows a pattern that developed in Spain is now most common in
northwest Europe, while the Ukraine pattern is mostly in Eastern Europe
and the Balkan pattern is most common in Central Europe.

About 8,000 years ago, said Underhill, a more advanced people, the
Neolithic, migrated to Europe from the Middle East, bringing with them a
new Y chromosome pattern and a new way of life: agriculture. About 20
percent of Europeans now have the Y chromosome pattern from this
migration, he said.



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Xxxx Xxxxx Xxxxxx
PhD Student
Department of Political Science
SUNY at Albany
Nelson A. Rockefeller College
135 Western Ave.; Milne 102
Albany, NY 12222



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