Travel Reference
In-Depth Information
Afterwards everybody surged to the edge of the fairground to watch the
fi nish of the great horse race. I found a vantage on a little escarpment.
The grass of the fairground petered out into an enormous gravel plain that
stretched out to blue mountains on the horizon. At fi rst nothing happened.
Then, at least three kilometers away, a tiny cloud of dust appeared. As we
strained to see through the heat haze the racers themselves gradually became
visible, still embedded in the cloud that they had generated. The excitement of
the crowd mounted as individual horsemen became recognizable.
The winners raced toward us and fanned out as they reached the ill-
defi ned fi nish line. And it became clear that these horsemen were not griz-
zled veterans of the steppes. They were young boys of ten or twelve, who had
ridden their tough little horses bareback at top speed across ten kilometers of
parched country. These tough-as-nails kids and their ponies, seamless super-
organisms of horse and rider, rode by in an impromptu victory parade as the
onlookers cheered.
The use of horses has been central to Mongolian identity for millennia.
And now there is evidence that the possession of these tough, tiny horses
helped to give some of these people of central Asia an enormous evolution-
ary advantage. The result was a pronounced change in the gene pool of the
people who lived in the entire region.
An individual's fi tness in the evolutionary sense is defi ned by how many
children he or she has. And it seems that some Mongolians were exceedingly
fi t. These individuals, in part because of their horses, had an amazing num-
ber of children.
The evolutionary success story of these extremely fi t nomads can be
traced through the Y chromosome, the chromosome that is passed from
father to son and that determines whether an of spring will be male. Like the
mitochondrial chromosome, part of the Y chromosome does not recombine
with other chromosomes. It simply accumulates mutations over time. Fam-
ily trees can be built using this part of the Y in exactly the same way that fam-
ily trees can be built using mitochondrial chromosomes.
Approximately a third of the males in Mongolia have a particular type
of Y chromosome. We can infer from this large number that many of their
recent male ancestors, who also carried this Y, must have been extraordinarily
