Prepared by Elisabeth Lindsay.
In the simplest terms, ancestral group refers to the genetic link from one's earliest ancestor, extending through time from ancestor to descendants. It is believed that the human race can be traced back to a limited number of migratory ancestral groups—perhaps even to a single mother or father. Those descending from a given ancestral group, thus, share a common ancestry. It is also believed that as the family tree branches out and the number of descendants for a specific progenitor increases, at a certain point in the ancestral line, the number of our progenitors begins to decrease, as we funnel back into our ancestral group.
DNA studies are often done to determine one's ancestral group and ethnic heritage, and may be especially useful to help supplement genealogical research where written records of one's ancestors are scarce to non-existent. However, ancestral group studies are also popular among the general population, as people seek to know more about their genetic makeup. The National Geographic, Genographic Project is a five-year, world-wide study aimed at mapping "humanity's genetic journey through the ages." For males, the Y-DNA test can be used to help to identify deep ancestral geographic origins on the direct paternal line, and for females the Mitochondrial DNA (mtDNA) test helps identify the ancestral migratory origins of the direct maternal line. Men, only, can be tested for Y-DNA, but both men and women can be tested for Mitochondrial DNA.