DNA from 2,000-year-old skeleton may put Indo-Europeans in East Asia By Bruce Bower
Heading East Excavations several years ago at an ancient cemetery in
Mongolia uncovered a man's skeleton, including this skull, that has
yielded genetic evidence of Indo-Europeans reaching eastern Asia at
least 2,000 years ago.Kim, et al.
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.
On the basis of previous excavations and
descriptions in ancient Chinese texts, researchers suspect that the
Xiongnu Empire — which ruled a vast territory in and around Mongolia
from 209 B.C. to A.D. 93 — included ethnically and linguistically
diverse nomadic tribes. The Xiongnu Empire once ruled the major trading
route known as the Asian Silk Road, opening it to both Western and
Chinese influences.
Researchers have yet to pin down the language
spoken by Xiongnu rulers and political elites, says archaeologist David
Anthony of Hartwick College in Oneonta, N.Y. But the new genetic
evidence shows that the 2,000-year-old man "was multi-ethnic, like the
Xiongnu polity itself,” Anthony remarks.
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.
Golden braidGold belt
ornaments such as this one lay among items placed in the ancient tomb of
a man in eastern Asia whose genetic makeup points to Indo-European
ancestry.Kim, et al.
"We don’t know if this 60- to 70-year-old
man reached Mongolia on his own or if his family had already lived there
for many generations,” says study coauthor Charles Brenner, a DNA
analyst based in Oakland, Calif.
Two other skeletons from the
Xiongnu cemetery in Duurlig Nars show genetic links to people who live
in northeastern Asia, according to Kim’s team. Other team members
include Kijeong Kim of Chung-Ang University and Eregzen Gelegdorj of the
National Museum of Mongolia in Ulaanbaatar.
The Duurlig Nars
man’s genetic signature supports the idea that Indo-European migrations
to northeastern Asia started before 2,000 years ago. This notion is
plausible, but not confirmed, says geneticist Peter Underhill of
Stanford University. Further investigations of Y chromosome mutation
frequencies in modern populations will allow for a more precise tracing
of the Duurlig Nars man’s geographic roots, Underhill predicts.
Scholars
have long sought to trace the origin and spread of related languages
now found in Europe, India and other parts of Asia. One hypothesis holds
that Indo-European languages proliferated via several waves of
expansion and conquest by nomads known as Kurgans who had domesticated
horses and thus could travel long distances. In this scenario, Kurgans
left a homeland north of the Black Sea, in what’s now Russia, around
6,400 years ago.
Another view holds that farmers from ancient
Turkey spread Indo-European tongues as they swallowed up one parcel of
land after another, beginning around 9,000 years ago.
Since 1978,
discoveries of 2,400- to 4,000-year-old mummified corpses with European
features in northwestern China, not far from Mongolia, have fueled the
Kurgan hypothesis (SN: 2/25/95, p. 120). Remains of large wheels found
with these blond-haired individuals raise the controversial possibility
that these foreigners introduced carts and chariots to the Chinese.
Add
to those discoveries a report in the September 2009 Human Genetics.
Geneticist Christine Keyser of the University of Strasbourg in France
and her colleagues found that nine of 26 skeletons previously excavated
at 11 Kurgan sites in northeastern Russia possess a Y chromosome
mutation pattern thought to mark the eastward expansion of early
Indo-Europeans. That same genetic signature characterizes the Duurlig
Nars man.
By 2,000 years ago, the easternmost Indo-European
languages were probably spoken in northwestern China, Anthony holds. So
an Indo-European speaker could have aligned himself with Xiongnu
political big shots and earned an eternal resting place in an elite
Xiongnu cemetery, in his opinion.
Kim agrees. The Duurlig Nars
man’s tomb lies close to the tomb of an especially high-ranking Xiongnu
man whom he may have served in some way, he suggests.
Kim’s group
plans to extract and study DNA from additional Duurlig Nars skeletons.
For now, Anthony remarks, "this new study from Mongolia is important
because it adds one more point of light to a largely dark prehistoric
sky.”
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