In 1962, Dr. James Watson and Dr. Francis Crick of the University of Cambridge received the Nobel Prize for their discovery of the double helix structure of DNA. 1 Deoxyribonucleic acid (DNA) is "a generic term for any of the nucleic acids which yield deoxyribose on hydrolysis, which are generally found in and confined to the chromosomes of higher organisms, and which store genetic information. 2 The genetic information found in DNA determines such things as which traits will pass from parents to offspring, i.e. eye color and hair color.
Three decades later, Dr. Bryan Sykes of the University of Oxford realized the significance of interpreting the genetic information stored in DNA for tracing one's ancestry. His groundbreaking work is excellently outlined in a book every genealogist should own, entitled The Seven Daughters of Eve. This national bestseller guides the reader through Dr. Sykes' personal account of the discovery that specific ancestral lines can be tracked through inherited DNA sequences. The title stems from the fascinating results of his research which identify seven women as the ancestors of the modern European population 3 Additional information about Dr. Sykes' project, including services which they provide to genealogists, can be found at the Oxford Ancestors webpage.
The Y-chromosome and the mitochondrion each contain genetic information which can be harnessed to aid family history research. These microscopic structures are composed of DNA sequences that pass from parents to offspring. The Y-chromosome descends from father to son, charted along the top line of the pedigree chart, and is currently used in surname studies. If your last name is Murphy, you and I can have this test performed and discover whether or not we share a common Murphy ancestor. This proves especially valuable to someone who descends from Irish and other heritages where the majority of historical records, normally used to trace genealogies, have been destroyed. With a common surname, such as Murphy, results are likely to come back negative, but for individuals with rare surnames, these tests produce phenomenal results. Persons with the same surname on both sides of the Atlantic can benefit from this study by determining if relationships exist between their families. Determining immigrant origins is one example of the tremendous help DNA studies provide.
Mitochondrial sequences reveal a person's matrilineal descent. The information stored in mitochondria passes from mother to daughter, charted along the bottom line of a person's pedigree chart. Due to Western surname conventions, and the subsequent lack of surname inheritance between mother and child, this test produces different results from the Y-chromosome test. Some current applications include identification of descendancy from Vikings, the Jewish Cohen family, Native Americans, and specific African tribes. The category Genetics, DNA & Family Health on Cyndi's List provides an excellent index to important websites concerning these topics. The Sorenson Molecular Genealogy Foundation, based in Salt Lake City, is an example of a project that provides free participation to its study. For additional information on how you can participate, see: Sorenson Molecular Genealogy Foundation.
Genealogists are just beginning to benefit from studies in the dynamic field of genetics. In the future, we will continue to see these two academic fields cooperate to reveal the intricate relationships of the human family.
1 Watson, James D. The Double Helix: A Personal Account of the Discovery of the Structure of DNA. New York: Norton, 1980.
2 Oxford English Dictionary. Online Edition. Available by subscription at: www.oed.com.
3 Sykes, Bryan. The Seven Daughters of Eve. New York: Norton, 2001.