Discovery Channel online is carrying this summary of research that claims to have made a remarkable discovery:

Genghis Khan left a legacy shared by 16 million people alive today, according to a book by a Oxford geneticist who identified the Mongol emperor as the most successful alpha male in human history.

They did this by tracing an unusual Y chromosomal "fingerprint" discovered during a generalized genetic survey of Central Asia. Eventually the trail of evidence lead right back to the only Mongol village in existence with a heavy preponderance of this trait and an oral tradition of being the birthplace of the Great Kahn.

Circumstantial, but still very interesting.