Sifting Through Those DNA Matches

Okay so you've had a DNA test done. And the results begin pouring in.

But which one should you really pay attention to! It seems like you are getting thousands at once at times! Most have 12-marker matches, or 24-marker matches. But the ones you want to watch for are those where you are most likely to have a common ancestor within 3-4 generations, and the ones you are most likely have that close of a relationship to will be 60-marker matches. Once you go past the 3rd or 4th cousin line, you will find it harder and harder to make a match.

First, contact the person if they have not listed their family tree for perusal. Ask if you can get just a straight lineage for their ancestors (parents, grandparents, gr-grandparents, gr-gr-grandparents, etc.). If something matches after about the gr-grandparents or gr-gr-grandparents, you build on it from there and begin sharing information with one another.

Family Tree Magazine's blog had a great article a couple of years back. Here is a portion of their advice:

"If you’ve taken an autosomal DNA test at 23andMe, AncestryDNA, or Family Tree DNA, you likely have a long list of genetic cousins. After sequencing portions of your DNA, the testing company compares your results to the results of other test-takers in its database. If you share enough DNA with another test-taker in the database, you’ll see that person in your list of matches.

The company evaluates how close you might be to another test-taker based on the amount of shared DNA. See the image for a sample list of AncestryDNA matches (with usernames blurred for privacy).

In this guest post, Blaine Bettinger, DNA expert and author of The Family Tree Guide to DNA Testing and Genetic Genealogy, shares a quick tip for identifying your DNA matches with the best chance of aiding your research.

For test-takers with ancestry in well-represented areas (such as Europe), the list of genetic matches may be thousands of people long. A few of those matches might be close, but most will be distant matches who share just a small segment of DNA. How should you process all those matches? Which ones should you focus on to attempt to find your common ancestry?

Focus on your closest matches first to increase your chances of finding family members and learning more about your family tree. If you’re lucky enough to have a predicted second cousin or closer, review that match’s family tree (if the match has provided one) for familiar names or places from your own family tree. Since the relationship is so close, you may only need to build his or her tree out for a couple of generations.

If the match doesn’t have a family tree, you might be able to build one for them or contact the match and ask for one.

What do I mean by your “closest” matches? Simple: The ones with whom you have an estimated relationship of fourth cousins or closer. You have a pretty good chance of finding common ancestry (such as a great-grandparent) with second cousins or closer, and a decent chance of doing the same (i.e., finding a shared second or third great-grandparent) with predicted third and fourth cousins. Beyond predicted fourth cousins, however, you’ll have difficulty finding a common ancestor. In most cases, you’ll only want to pursue these more distant matches if you have additional concrete evidence that you share ancestors."

This all excellent advice and I hope it helps when you begin receiving your test results!

If you haven't done a DNA test yet, you can order your test from Ancestry.com HERE.

Or  from 23andMe HERE: