Genes on the March
MY mother always said I must be part Mongolian, because of my lotus-pale complexion and squid-ink black hair. “Something you’re not telling me?” I was tempted to ask. But I knew she’d visited Mongolia with my father long after I was born. What I didn’t know is that one out of every 200 males on earth is related to Genghis Khan.
An international team of geneticists conducting a 10-year study of men living in what once was the Mongolian empire has discovered that a surprisingly large number share the identical Y chromosome, which is passed down only from father to son. One individual’s Y chromosome can be found in 16 million men in Asia, from Manchuria, near the Sea of Japan, to Uzbekistan and Afghanistan in Central Asia.
The likeliest candidate is Genghis Khan, a warlord who raped and pillaged one town after another, killing all the men and impregnating the women, sowing his seed from China to eastern Europe. Though legend credits Genghis Khan with many wives and offspring, he didn’t need to do all the begetting himself to ensure that his genes would flourish. His sons inherited the identical Y chromosome from him, as did their sons and their sons’ sons down a long, winding Silk Road of legitimate and illegitimate progeny.
His equally warlike oldest son, Tushi, had 40 legitimate sons (and who knows how many misbegotten), and his grandson Kublai Khan, who figured so large in Marco Polo’s life, had 22 sons. Their genes scattered exponentially in an ever widening fan, and the process really picked up speed in the 20th century, when cars, trains and airplanes began propelling genes around the planet and stretching the idea of “courting distance,” which used to be only 12 miles — how far a man could ride on horseback to visit his sweetheart and return home the same day. Now it’s commonplace to have children with someone from thousands of miles, even half a world, away.
Khan wasn’t trying to create a world in his image; his fiercest instincts had a mind of their own, and his savage personality spurred them on. Most people don’t run amok on murderous sprees, thank heavens, but history is awash with Khan-like wars and mayhem. In their wake, gene pools often change. One can only surmise that wiping out the genes of others and planting your own (what we call genocide) must come naturally to our kind, as it does to some other animals, from ants to lions.
Typically, wandering male lions attack a pride, drive off the other males and kill their offspring. Then they mate with the females, ensuring that only the invaders’ genes will flourish. A colony of ants will slaughter millions of neighbors, provided they’re not family (somehow they can spot or whiff geographically distant kin they haven’t met before). Human history is riddled with similar dramas, but they are war’s legacy, an unconscious motive, not a blueprint for action.