"The Journey Of Man" does a tracking of human migration based on DNA of tribes from Africa, through India and through Europe etc. The way they can tell who came first and who that followed came in what order are based on genetic markers in human DNA. The more isolated tribes and people still have the most pure and undiluted dna. Anyone interested in this should go rent or buy the dvd, it's very very interesting.

The Journey of Man: A Genetic Odyssey - Wikipedia, the free encyclopedia