Bryan Sykes is talking about the descendents of Genghis Khan (Temujin) again. It seems ~8% of men in a broad swath of Central Asia are direct patrilineal descendents of the World Conqueror (or his father or grandfather, that is, his near relatives). Here is a test being sold by Sykes' company to see if you are of the Khan Y lineage. But remember, we are talking about the direct male line, this doesn't take into account all the Khan's daughters and their descendents, and the daughters of his male descendents! Here is a quote sometimes attributed to Genghis Khan:

The greatest happiness is to vanquish your enemies, to chase them before you, to rob them of their wealth, to see those dear to them bathed in tears, to clasp to your bosom their wives and daughters....