Travel Reference
In-Depth Information
Consider ordinary males living a thousand years ago who were not lucky
enough to carry the unknown Mongolian's Y chromosome. On average they
increased in number by a piddling 4.5% per generation (assuming twenty
years per generation). This small reproductive rate of return was enough,
through the magic of compound interest, to yield an average of ten males at
the present time for every male who lived then.
The lucky unknown Mongolian, however, benefi ted from a much higher
rate of interest. His male descendants increased on average by 33.2% per gen-
eration, or 1.65% per year. This would not have been a rate high enough to
excite the titans of Wall Street. But it would have been enough over a thou-
sand years to yield 16,000,000 male descendants.
The huge increase in the unknown Mongolian's descendants did not take
place at a uniform pace. It seems likely that Genghis Khan's penchant for
rape and pillage, and Kublai Khan's nightly defl owering of one or more vir-
gins, gave the unknown Mongolian's Y a big boost near the start of its career.
But it also turns out that the reproductive ef orts of the Khans, impressive
though they were, could not have been enough to account for the astound-
ing number of their descendants at the present time.
Let us suppose that by the time Kublai Khan died, a little more than 700
years ago, his ef orts and those of his lubricious relatives had increased the
number of the unknown Mongolian's male descendants to 10,000. This
would be a gigantic increase in numbers from the time of that solitary Mon-
golian, especially if we assume the most likely estimate that he had lived only
200 years before Genghis Khan. Then, if the reproductive success of those
descendants had subsequently fallen back to the worldwide average of 4.5%
per generation, by the present time they would number only 48,000. It is
clear that many Mongolians in addition to the Khans themselves benefi ted
reproductively from their conquest of much of the known world.
Genes, environment, and domestication
As the moon completely masked the sun late on the afternoon of August 1
and the sun's pearly corona suddenly fl ashed into view, a gasp went up from
