Travel Reference
In-Depth Information
these soldiers, and to make assurance doubly sure, Genghis Khan left a post-
humous order to have the soldiers themselves killed on their return home, so
that the secret of the tomb's location died with them. You are free to believe
all this or not, as you wish, but the legend has inspired generations of explor-
ers to search for the tomb.
Albert Lin at my home institution has explored the most likely area that
conceals Genghis Khan's tomb by satellite photographs and on horseback.
He has found traces of hundreds of tombs and other structures that post-
date Genghis Khan. Fallen trees have torn up the ground in many places and
revealed roof tiles of substantial buildings, showing a Chinese presence in
the area subsequent to the time of Genghis Khan. Much archeological detec-
tive work will be needed to disentangle the complex history of the region.
Approximately a thousand years ago, perhaps as little as two hundred
years before Genghis Khan, an unknown Mongolian Adam had the only copy
of this Y chromosome. It is a fascinating exercise to work out how reproduc-
tively successful he and his descendants must have been.
At the time of that unknown Mongolian the world's population was
about one-twentieth as large as it is today. This means that on average each
person who lived then has twenty descendants living today, half of whom
are male. (Of course, the luckier of these ancestors have more surviving
descendants than that, and many unlucky ones left no present-day descen-
dants at all.) But when we count up the numbers of those unusual Y chro-
mosomes carried by males at the present time, we fi nd that this unknown
Mongolian had, not ten, but 16,000,000 male descendants! This chromo-
some is truly in a class by itself.
At fi rst glance, you might think that the unknown Mongolian was one
and a half million (16,000,000 divided by 10) times as successful at repro-
ducing as the average male of that time. But the advantage was not really
that immense. The carriers of the unknown Mongolian's chromosome did
benefi t from an increase in their reproductive success compared with the
rest of the population, but the dif erence was compounded over a thousand
years. Like the multiplying advantage of compound interest, even a rela-
tively small increase in fi tness each generation can produce dramatic results
over so much time.
