Editor's note: This column was originally published May 3, 2013.
A common problem that people encounter when trying to trace their roots on a particular parent's side using DNA testing is that the parent is dead or not available to them. The reader below has encountered this roadblock, but there are ways around it.
I was adopted in Nova Scotia, Canada, in 1972, and my province has closed adoption records. I now know the identity of my white birth mother, but she has refused contact with me and will not say who my black birth father is or was. With no name and very few clues about him, I have been unable to find any leads on his identity. I wonder if there is anything else I can do.
From what I understand, DNA testing will not help me find out about my birth father's ancestry, unless I have a relative from my father's side to compare DNA with. Is that correct? Is there any type of DNA testing that could help me in my search for my father? —Kate Foster
As more people have their DNA tested and as the results databases grow, you will have an increasingly better chance of connecting with your birth father by genetic means. While it is true that you are unable to trace your father's identity through his Y-DNA (the traditional male paternity signature) because a female does not inherit it, do not despair: There is another method. Autosomal DNA testing looks at the 22 pairs of chromosomes that do not determine gender. This can be very useful in identifying relationships within five generations of yourself, without being limited to only maternal ancestors.
It is true that your results will be most useful if your biological father or one of his close relatives (preferably his brothers or sisters or his first cousins) also had genetic data registered with the DNA testing company you use. Companies like 23andMe (through DNA Relatives) and Family Tree DNA (through Family Finder), as well as Ancestry.com and Genographic, can compare the data from these autosomes for shared segments. You should take tests with each of these companies, since their databases are proprietary—that is, they are not shared or overlapping.
The closer the genetic relationship you have with a person in one of these databases, the more identical segments of DNA you will share. And these companies even determine, through the lengths of these segments, if you have a brother or sister in the databases or, indeed, if you descend from a parent. But we stress that this is a very long shot.
According to the 23andMe website, "DNA Relatives uses the length and number of these identical segments to predict the relationship between people." If your birth father himself has contributed his DNA results, you will be able to tell [if] he is your father. A 30 to 40 percent match with someone probably indicates that the person is your half-sibling. 23andMe and Family Finder both display predicted relationships between you and the people whose DNA aligns with yours to some degree. This means that by submitting your DNA results, you would be casting a net and hoping that a relative on your father's side has contributed DNA as well. Should you find any such people, you can contact them through the company you have both joined.
The autosomal results clearly separate what you inherited from your father, as opposed to what you received from your mother's side of the family. Due to the difference in race, you should be able to see which side is which. Concentrating on your paternal side, you can see what ancestry he has and if he may have passed on any risks for medical conditions. Any non-African ancestry, or particularly high chances for certain medical conditions, could provide clues as to your paternity, too, since companies test for these things. At the very least, this will allow you to understand your own ancestry and what risks you may have inherited from his side.
Outside of DNA, there still may be some options for tracking down your biological father's ancestry through more traditional routes. Now that you know your biological mother's name, perhaps you can start by further researching her and her close relatives. This may bring to light any men she came in contact with around the time of your birth. Were they neighbors, co-workers, school mates or in some other way connected? You can try finding resources like city directories, phone books, local newspapers and school yearbooks to help determine this.
Since you'll be searching fairly recent resources, the best place to find these may be in the local library where your biological mother grew up or at the school(s) she attended. For that matter, there may be someone working in one of these centers who knew your parents who can tell you about them. If you can put together a list of possible fathers, you can work toward ruling them out until you come to one (or a few) with whom it might be worth following up. Researching your birth mother's family could also lead to someone willing to share more information with you about your father.
Henry Louis Gates Jr. is the Alphonse Fletcher University Professor and founding director of the Hutchins Center for African and African American Research at Harvard University. He is also the editor-in-chief of The Root. Follow him on Twitter and Facebook.
Send your questions about tracing your own roots to TracingYourRoots@theroot.com.
This answer was provided in consultation with Kyle Hurst, a researcher from the New England Historic Genealogical Society. Founded in 1845, NEHGS is the country's leading nonprofit resource for family history research. Its website, AmericanAncestors.org, contains more than 300 million searchable records for research in New England, New York and beyond. With the leading experts in the field, NEHGS staff can provide assistance and guidance for questions in most research areas. They can also be hired to conduct research on your family. Learn more today.