Saturday, January 30, 2010

Europeans in Ancient Mongolia

From Science News:

Dead men can indeed tell tales, but they speak in a whispered double helix.

Consider an older gentleman whose skeleton lay in one of more than 200 tombs recently excavated at a 2,000-year-old cemetery in western Mongolia, near China’s northern border. DNA extracted from this man’s bones pegs him as a descendant of Europeans or western Asians. Yet he still assumed a prominent position in ancient Mongolia’s Xiongnu Empire, say geneticist Kyung-Yong Kim of Chung-Ang University in Seoul, South Korea, and his colleagues. . . .

This long-dead individual possessed a set of genetic mutations on his Y chromosome, which is inherited from paternal ancestors, that commonly appears today among male speakers of Indo-European languages in eastern Europe, central Asia and northern India, Kim’s team reports in an upcoming American Journal of Physical Anthropology. The same man displayed a pattern of mitochondrial DNA mutations, inherited from maternal ancestors, characteristic of speakers of modern Indo-European languages in central Asia, the researchers say.

The data certainly seem to be evidence for the spread of people from eastern Europe or western Asia in the first millenium BC, but of course there are the usual caveats. What is not really in dispute, though, is how far some mutations can spread in just a few thousand years. Whatever model you favor for the spread of these genes, they speak of intimate contacts between prehistoric people thousands of miles apart. The modern inhabitants of, say, western Ireland are not simply the descendants of the Mesolithic inhabitants of the region, nor are they simply the descendants of this or that group of invaders. Instead, we see that genes have spread across Eurasia by some combination of migration, conquest, and marriages with outsiders. (The picture shows the skull of the man under analysis.)

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