Tips & Resources for DNA Testing in Your Genealogy Research

By Diane Haddad’s announcement about coming improved matching for AncestryDNA autosomal tests—in part because of the half-million results in the AncestryDNA database—is another sign of DNA’s increasing popularity as a genealogy research tool.

If you’ve tested with AncestryDNA, your matches will be updated automatically, and for free. Your list of matches will probably shrink, as the more-distant ones drop off. Learn more about the upcoming improvements on the blog.

For those who haven’t yet ventured into genetic genealogy, and for those who have (whether with AncestryDNA, Family Tree DNA, 23andme or another company) but are staring at their results and asking “now what?,” these tips and resources can help:

  • Y-DNA tests can tell you about matches along male lines (your father’s father’s father and so on). Mitochondrial DNA tests can tell you about your maternal lines (mother’s mother’s mother’s … ); but because this type of DNA mutates so infrequently, it’s hard to tell if a match is related to you through a recent or more-distant ancestor.
  • Autosomal DNA can contain genetic material from people in any branch of your family tree, making autosomal tests a useful tool for a broader array of research questions than using Y-DNA or mtDNA alone. But remember that back beyond about your great-grandparents, not all your ancestors are reflected in your autosomal DNA. There’s no test (yet) that can tell you which part of your autosomal DNA came from which ancestor.
  • A “triangulation” strategy can help you narrow the DNA profile from a particular ancestor. In our “Using Genetic Genealogy to Find Family History Answers” guide, Blaine Bettinger gave the example of a woman named Helen who was adopted as a baby and died without knowing her biological parents. Helen had a son and a daughter, each of whom also had children. A grandchild from each offspring took autosomal DNA tests. That way, a match to both grandchildren would have to be related through Helen or her husband. If only one grandchild or grandchildren who were siblings took a test, a match might be related through the other parent—not Helen’s line.

    See more examples of how DNA testing can help you answer research questions in our on-demand webinar Using DNA to Solve Family Mysteries.

  • Be prepared for a genetic genealogy test to uncover surprises in your family tree. One man’s parents divorced after he gave them DNA tests as gifts, and a match to his dad turned out to be a son no one knew about.