Most family historians are accustomed to using records—information captured in some physical form—as the basis for their research. Traditionally, these records have been paper documents or images on film. We have sought them by visiting or corresponding with the libraries, archives, and individuals that held them.

More recently, we have used information recorded in other physical forms—photographs, sounds recorded on plastic discs, magnetic tapes, or information converted to digital bits and stored on magnetic or optical disks, not to mention the information recorded by others that can come to us through the Internet.

Occasionally, information has come directly to us by someone who knew the facts, or was derived from a house, gravestone, tool, article of clothing, or other item associated with a person. In both cases, we have attempted to preserve the information by recording it as soon as possible.

Now we have access to DNA research, which can analyze the actual substance that makes each individual (or pair of identical twins) different from all other human beings. This new tool has already been used in widely publicized studies like those identifying the remains of the Russian imperial family, the Romanovs, or in linking Thomas Jefferson’s descendants to his slave and supposed mistress, Sally Hemings.

Few in the genealogical community foresaw how close we were to having this new tool available for research. References to "taking shovels along for cemetery research" or "core-sampling Grandpa" treated humorously a prospect thought at best to be in the indefinite future. Now, DNA profiling or matching is being offered on a commercial basis at prices within the reach of serious family historians.

The DNA testing being offered to family historians should not be confused with the genetic tests that help uncover actual or potential medical problems. Instead, they are more like the matching process, sometimes called forensic testing, that identifies or clears accused criminals on the basis of physical evidence left at the scene of a crime.

The other, called mitochondrial DNA (mtDNA), is found outside the nucleus in small structures called mitochondria. It is passed unchanged from mother to child.

Thus the Y-chromosome DNA is found only within the all-male patrilineal line—the line through which the family surname is transmitted to sons, unless their relationships reflect adoptions or marital infidelity along the way. The mtDNA is characteristic of the mother’s all-female line—the so-called umbilical line that’s difficult to trace because a woman’s surname changes with marriage in each generation.

These are the only two lines current DNA tests can identify or match to other individuals belonging to the same line. In other words, DNA testing is only applicable to lines going back through two of our eight great-grandparents—our father’s paternal grandfather and our mother’s maternal grandmother. Because women don’t carry the Y-chromosome, their paternal male line can be traced only through a DNA sample from a father or brother.

Lines through other great-grandparents can be traced through DNA only if a sample is available from an aunt, uncle, or cousin who descends through an all-male or all-female line.

The well-publicized Jefferson-Hemings tests were based on Y-chromosome samples from male descendants of Thomas Jefferson’s paternal uncle, since Jefferson himself had no surviving male descendants from his marriage. The tests that identified the bodies of the Romanovs, the Russian imperial family, were positively identified through mtDNA testing of a sample from Prince Philip, who shares the same maternal line from Queen Victoria.

Family Tree DNA focuses on recent relationships and will report whether samples from several individuals are actually related, with a statistical determination of how many generations back the most recent common ancestor (MCRA) will be found, based on analyses of both mtDNA and Y-chromosome DNA, where present. The firm’s scientific work is under the supervision of Dr. Michael Hammer of the University of Arizona. The cost of testing, per person, is $219, although discounted prices are available for multiple-individual tests aimed at family reconstructions. Male samples get two tests—Y-chromosome and mtDNA—for the same price. It is preferable to use the sample from a brother rather than sister because that way the father’s line as well as the mother’s can be determined.

Dr. Hammer’s work has included a study of the Cohanim marker, found on the Y-chromosome of Jewish men who bear the name Cohen, signifying membership in the hereditary Jewish priesthood through male-line descent from Aaron, brother of Moses and the first Jewish high priest.

The Oxford Ancestry approach is more anthropological and is currently based on mtDNA tests only, although Y-chromosome tests are expected to be added shortly. Under the direction of Oxford’s Dr. Bryan Sykes, it will provide a certificate that identifies the genetic code for some four hundred units along the mtDNA chain and will identify the client’s maternal line. There are some thirty such lines, which diverged between 8,000 and 170,000 years ago, and from which we are all descended. The time estimates are based on the rate of random, single changes in the DNA code, which occur about once every 20,000 years. Oxford Ancestry’s tests are $180 each, $324 for two ordered together, and $144 each for additional tests ordered at the same time.

Dr. Sykes’ work has concentrated on the seven matriarchal groups from which most Europeans are descended, and which arose between 8,000 and 40,000 years ago. They have been popularized as "daughters of Eve" and have been given names starting with the distinguishing letters by which they are designated in scientific literature.

There is also another program with a genealogical orientation, under the direction of Dr. Scott R. Woodward of Brigham Young University, but information on test results is not provided to participants. They are asked to take part solely to help in a research program that aims to link DNA tests of 100,000 volunteers with worldwide locations from which participants’ ancestors came. Each participant is asked to submit a four-generation pedigree chart and to have a small blood sample drawn, for which they are paid $10. The program, launched in March of 2000, attracted more than 2,100 volunteers by late June, and plans have been made to accommodate additional volunteers at the Federation of Genealogical Societies conference in Salt Lake City in September of 2000.

Also, a potential program at Howard University has been reported in the press. Dr. Rick A. Kittles is planning a program that would identify for African Americans the area of Africa from which their male-line or female-line ancestor came.

All of the programs now available to family historians are based on samples from living individuals, but the procedures for extracting DNA from human remains, even after many years, is widely understood, and exhuming long-dead ancestors for purposes of DNA testing is no longer a subject to be treated in jest.

The tests now available won’t solve all of our research problems, but they can be extremely useful in selected cases to confirm family traditions of relationships or research hypotheses where there are no records that can lead to a more convincing conclusion.

Further Reading
Candace L. Doriott. "Genealogical Genetics." Genealogical Computing 19:1 (July/Sept 1999): 45-46.

______. "Genetic Codes Unraveled: New Clues for a Human History." Ancestry 18:1 (Jan/Feb 2000): 14-21.

Mark Howells. "Double Helix Genealogy." Ancestry 18:1 (Jan/Feb 2000): 52-55.

Bryan Sykes, editor. The Human Inheritance: Genes, Language and Evolution (Oxford, 1999).

Molecular Biology Web Book <www.web-books.com/mbiol/ Default_m.htm>.

Linda Tagliaferro and Mark V. Bloom, Ph. D. A Complete Idiot’s Guide to Decoding Your Genes (New York: Alpha Books, 1999).