I remember watching a show but I can't remember what channel or what the name was. Maybe 2 years ago. It was some guy doing genetic testing for DNA, and there was one string in the DNA that he thought related to the original human who left Africa. He traveled the world, testing people/tribes that he thought were related for that string of DNA and he ended up finding it and being able to trace the path that the original humans took to populate the world. Anyone know the name of the show or the guy?