National Geographic is conducting a research project (The Genographic Project) to analyze historical genome patterns by sampling DNA from people all over the world. The main aim is to sample from various indigenous peoples from around the world but the public can participate as well. The website for the project is here. There is a charge for a participation kit, which is used to defray the costs of the study. You can have your mitochondrial DNA, which follows your maternal lineage, or if you are a male, the Y-chromosome, which follows your paternal line analyzed. I recently did the test for my Y-chromosome and I am a member of Haplogroup O with the M175 marker. My earliest male ancestor emerged roughly 50,000 years ago in Africa and is the common ancestor of every non-African male alive today. The man with the M175 marker emerged about 35,000 years ago during the ice age somewhere in Central or East Asia. There were probably something like 100,000 Homo sapiens alive at that time.