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.