In 2003, researchers from around the world released a paper that suggested that 8% of all Mongolian males have a common Y chromosome because they are the descendants of Genghis Khan (See “The Genetic Legacy of the Mongols,” 2003, Zerjal, et. al., American Journal of Human Genetics, 72: 717-721). The researchers examined the Y chromosome variability of over 2000 people from different regions in Asia and discovered a grouping of closely related lines. The cluster is believed to have originated about 1,000 years ago in Mongolia and its distribution coincides with the boundaries of the Mongol Empire.
Genghis Khan’s empire (he ruled from 1206 – 1227) stretched across Asia from the Pacific Ocean to the Caspian Sea and was reportedly extremely prolific. Khan’s son Tushi had as many as 40 sons. His grandson Kublai Khan is reported to have had as many as 22 sons, and perhaps many more. Together this family may have as many as 16 million descendants alive in Asia today. It is extremely important to note that until DNA can be extracted from Khan’s bones (which have never been found), there is no definitive proof that this Y chromosome cluster is actually descended from Genghis Khan.
When Family Tree DNA compared the markers in the paper to their database they determined that the Y chromosome cluster belongs to Haplogroup C3 (M217+). Forty-seven samples in their database exactly matched the markers identified in the paper. The company has summarized the marker results from the paper and have made that information freely available.
A newly released study from Russian scientists examined the Y chromosomes of 1,437 men from 18 Asian ethnic groups (Altai Kazakhs, Altai-Khizhis, Teleuts, Khakasses, Shor, Tuvinians, Todjins, Tofalars, Soyotes, Buryats, Khamnigans, Evenks, Mongolians, Kalmyks, Tajiks, Kurds, Persians and Russians). The researchers discovered that approximately 35% of Mongolians possess the “Khan” Y chromosome. Surprisingly, the results of the study suggest that although the Mongol Empire held eastern Russia for 250 years, there are few “Khan” Y chromosome carriers in that region.
You can read more about the 2007 study at UK Channel 4 or at Scientific Blogging.