Prepared by Elisabeth Lindsay.
DNA studies are collaborative projects based on genetic testing applied to link specific individuals, to develop lines of descent among people with the same surname, or to map the genetic origins of large segments of the population, otherwise known as ancestral groups. DNA tests are performed on cell samples from individuals, often through a simple cheek swab. Individual test results are then compared against others to determine genetic information or markers, which can suggest a genetic connection. DNA studies do not identify a common ancestor by name, but can confirm or deny a line of descent. DNA studies, while not absolute, can suggest the degree of probability that a relationship exists. It is that probability factor that makes DNA studies so attractive to consumers. Various types of DNA studies exist, from individual projects based a common surname to larger pool studies offered by a growing multitude of genetics testing companies. In addition, an ambitious five-year study is underway by the National Geographic Society aimed at mapping global ancestral migrations.
DNA studies have become increasingly popular in genealogy, in many cases helping researchers identify ancestral relationships for which they have no documented proof. DNA studies do not, however, stand on their own and must be supported by traditional genealogy research, working back in time from what is known. Surname studies are one of the most popular DNA studies in genealogy, in which participant DNA results are compared against others have the same surname or variant. Other projects may focus on identifying specific ethnic origins or ancestral groups such as African, Native-American, or Australian Aboriginal studies, to name a few. The most popular application of DNA studies is the Y-DNA test which traces the paternal line in a direct line of descent, father to son. The mitochondrial or MtDNA test traces the maternal line and applies to anyone, male or female. The autosomal DNA has become more recently available. To participate, genealogy researchers will want to become familiar with the type of DNA test used for a particular study, its primary purpose and limitations.