Another name for genealogy DNA is molecular DNA because that is where the science of family begins. Until the late 1980s the only tool available for people seeking information about their ancestors was historical records and the remembrances of grandma and grandpa. You might be able to recall the names of your grandparents, but do you know the names of your great-grandparents? Precisely. Few people do. Advances in DNA typing are filling in the blanks.
Almost all cells in the human body contain DNA, deoxyribonucleic acid. DNA is a string of proteins that tell our bodies how to grow; whether to have blue eyes or brown, whether to have a predisposition to heart disease or cancer. It is the complete genetic blueprint of people. It makes each of us unique but also similar to our parents and ancestors.
There are two types of cells used to map out genealogy, Y-Chromosome DNA, and Mitochondrial DNA or mtDNA. The Y chromosome exists in men and is passed down from fathers to sons. Women don’t have a Y chromosome and thus cannot be tested for their paternal heritage. Men can know who was their father’s father, and on and on through hundreds of generations. Generally the paternal line can be tested to the origin of the surname, although some African-Americans have surnames dating back just to the 19th century.
Mitochondrial DNA is the opposite of Y-DNA and is passed down from mothers to her offspring of both genders. The difference with this kind of DNA is that both men and women have it and can be tested for it. Therefore, a man can learn about the ancestral lines of his mother and his father, but women can only know the lines of their mother. In order to learn information about their father’s ancestry, they have to have their father, brother or male cousin tested.
Despite the limits of DNA testing for women, mitochondrial DNA has a slower rate of mutation than Y-DNA. The results of clean strains cover more years. While Y-DNA may go back for 12 generations, Mitochondrial DNA can reflect 30 generations or more.
When scientists test DNA for genealogy they assign letter values to “markers” which are specific spots on a microscopic strand of DNA. The values reveal a pattern that shows similarities to other people in DNA data bases. Some strands have fewer mutations or differences, and the more you have in common with others in the DNA databases, the more likely they are to have a common ancestor with you.
One of the limits of Mitochondrial DNA is that the mitochondria exist in the cytoplasm of the cell instead of the nucleus. As stated before, mtDNA mutates very slowly. When scientists find an exact match it is difficult to know if the common ancestor lived recently or hundreds of years ago.
One famous use of mitochondrial DNA involved the identification of the Russian Royal family. Czar Nicolas, his wife and their five children were all executed by the Bolsheviks in 1919. For nearly 100 years their fate was not known however with the fall of the Soviet Union a search for the bodies unearthed the probable graves.
Prince Philip of England provided a DNA sample in which mtDNA was extracted to determine if the Russian Royals were within the newly discovered graves. Prince Philip shares the same maternal line as Queen Victoria, as did Czar Nicholas. The DNA test proved the bodies in the graves were indeed the Romanov family, the last royals in Russia.
It is easy to give a DNA sample. 100 labs around the world provide the services. Find an accredited one, order the kit and begin your search with genealogy DNA for ancestors the world over.