The rise of Genghis Khan and the Mongolian empire was responsible for the annihilation of an estimated 40 million people, but there were clearly more than a few conquests off the battlefield as well. A 2003 study suggests that 1 in 200 men are direct descendants of Genghis Khan. Studies of Y-chromosome data found that almost 8 percent of men living in the former Mongolian empire carry nearly identical Y chromosomes. Researchers believe this is attributed to a unique set of social selection circumstances put into play by the spread of the Mongolian empire. In this week’s "Today I Learned," research scientist Albert Lin elaborates on Genghis Khan as a romantic.