AncestryDNA, 23andMe, the Genographic Project and AncestrybyDNA all offer DNA testing to determine ancestry. These services analyze and compare DNA to determine an individual's ancestral origins.
AncestryDNA suggests that looking at an individual's DNA will help the person to identify possible relatives when researching family history. The service 23andMe determines which parts of an individual's DNA come from specific populations around the world. The Genographic Project from National Geographic uses DNA results to formulate theories about how humans populated the earth in the early years of the species. AncestrybyDNA offers the option to compare an individual's determined ancestral origin to present-day DNA trends.