DNA: My New Genealogy Obsession

I know I’m a little late to the party.  I’ve never been much of an early adopter for anything, whether it’s technology or fashion.  But if I’d jumped on the DNA bandwagon earlier, maybe by now I would’ve knocked down some brick walls by combining DNA results with my paper research.  On the positive side, in the time I’ve been procrastinating, DNA tests have become less expensive, and many more people have tested, so theoretically I can jump right in and find tons of cousins.

I had already tested myself on Ancestry and 23andme, my mother on 23andme, and my uncle’s Y-DNA on FamilyTreeDNA.  Then I gave my children and my ex-husband DNA kits for Christmas, and the results have all come in.  So, as I was deciding on classes to take at the RootsTech conference last week, I decided to focus on learning about DNA.  I already knew about the different types of tests, the 23 pairs of chromosomes, and how the X and Y chromosomes are inherited.  But I really had no idea what to do with all my matches on Ancestry and other sites. And then there’s all the jargon, like triangulation, recombination, and chromosome mapping.

At the conference, some of the classes were WAY over my head, and some were surprisingly too basic.   But I was able to absorb a few helpful tips, which is at least a start.  I know there are lots of online resources as well, so now I’m motivated to find those and take my beginner’s knowledge to the next level.  Here’s some of what I learned:

In your DNA matches on Ancestry, you can look at the number of centimorgans you have in common, as well as the number of segments.  All I know about centimorgans is that it’s a unit of measurement related to DNA.  The more centimorgans and the more segments in common, the more closely you’re related.  To find the centimorgans for a specific match, go to your matches list, click on “View Match”, and then click on the little “i” icon.  There you’ll find the number of centimorgans and segments for that match.

So what does it mean?  There’s a table by Blaine Bettinger at the International Society of Genetic Genealogists website here, about two-thirds down the page.  It shows the various relationships associated with ranges of centimorgans.  For example, the table shows that the range for the parent-child relationship is 3,266 to 3,720, with an average of 3,471.  My daughter shares 3,448 centimorgans with me, right in the middle of the range.  So you can compare the centimorgans in common with a match, and then refer to the table to see what the relationship might be.

You can make notes on all your matches, which can be a quick way to identify them from the summary page.  To make a note, click on “View Match”, and then “Add Note”.  Someone at the conference suggested that I put the number of centimorgans and segments there for easy reference, but you can use this feature for whatever you think will be helpful to you.  On the Summary page, you’ll now see a little note icon which you can click on to see the information.

Some of your matches will indicate “No family tree.”  Sometimes they really have no tree, but sometimes they just haven’t linked a tree to their DNA results.  To check this, click on “View Match” and if you see a drop down menu from which you can select a tree, then you can view a tree to see how you might match.  If there’s no drop down menu of tree names, then there’s no tree.

Even if there’s no tree to view, or if the tree is private, you can use a neat little tool called the Shared Matches feature.  Just click on “View Match” on the Match Summary page, and then click on the tab “Shared Matches”.  You’ll see a list of matches you share with the person, which could provide a clue regarding how you’re related.

Another helpful feature is the “Hints” tab at the top of the Match Summary page, which is a type of filter.  If you click on that tab, only those matches with shared ancestors will appear.  When you view these matches, Ancestry will show you the Most Recent Common Ancestor (“MRCA”) which you share with that match, according to your trees.  I went through all of  the “Hints” matches in my DNA results, and added the MRCA names to the match’s note, so I can see from the Summary page exactly how we’re related.  This is extremely helpful, too, when you use the “Shared Matches” feature for those with private or no trees.  If the matches with private or no trees share DNA with the matches which have the MRCA identified, then you know generally how you’re related.

As I went through this process, I found a couple of meaningful matches.  In my tree, I include some “Speculative Direct Ancestors”.  These aren’t yet properly documented as the parents of the previous generation, but I have them in my tree so I can test the hypothesis.  I use a big question mark as the Primary Photo so it’s clear that I’m not sure about the relationship.

So when I found matches with a Speculative Direct Ancestor as the MRCA, I thought that was pretty exciting.   There’s one in particular where the MRCA, Freelove Lamb, was married twice, and my DNA match descends from Freelove and her first husband.  The descendants of that marriage are well documented, but my paper trail to Freelove is weak.  So the fact that we match is pretty significant, and is an indication that I’m on the right track.

This match made me think of other brick walls I might be able to solve with DNA.  In order for Ancestry to find a MRCA, you need to have your Speculative Direct Ancestor in your tree.  So I added another speculative ancestor, Ishmael Furlong, to enable the Ancestry algorithm to identify him as an MRCA with a match who has Ishmael in his or her tree.  If I match with one of Ishmael’s descendants, then I may be able to conclude that my James Furlong was Ishmael’s son.

You can also search your matches by surname or by geographic location, which is going to come in really handy for me with my ex-husband’s matches – he has over 1,500 of them!

I learned a little about chromosome mapping and triangulation, but not enough to repeat it here.  I have a lot more to learn about all of it, but I especially want to understand better what constitutes proof when it comes to DNA, and how to organize matches and manipulate the data.   More to come as I explore this vast new arena!


4 thoughts on “DNA: My New Genealogy Obsession

  1. You lost me at Centimorgans😝! Chris you have entered a new dimension ……that of a genealogy scientist!!!

    Your Dad would be soooooo proud of you!!❤️


  2. Fascinating, Chris! Another significant tool in your research toolbox, it seems. Fascinating interconnections among the various search vehicles apparently. Had wondered how the DNA findings might help, if they did at all, and you have given an excellent overview with personal family examples to illustrate how DNA can be so significant in genealogical research. Another service has been advertised recently called “My Heritage”, I believe? Seems to be focused on various documents which can be linked to ease the research process? Thanks again for all you are doing and sharing with us!


  3. Cathy Ivins has become our expert on DNA so give her a call/email with questions if you have them. She gave a terrific presentation on DNA and she now has a following. Getting together to plan our next Ancestry Fair on November 11 at BCCC in Perkasie again. Everyone loved it. Put it on your calendar.


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