I am in the midst of full blown genea-mania after many months of down time. With luck I will return to sanity in time to pay bills before the utilities are shut off.
I blame FamilyTreeDNA. Their new reporting of X chromosome matches dragged me back into the DNA analysis quagmire. Autosomal testing is an appealing concept to those of us without Y chromosomes. Take a sample of our DNA and compare it to thousands of others. When there is a statistically significant match you can assume a genetic connection within measurable history. Not a shared haplogroup where the common ancestor was dead long before Moses gathered animals into the ark. A connection within a few centuries. A connection that can, in theory, be found.
Autosomal chromosomes can also be mapped. Again, in theory. Imagine being able to see a match and being able to identify the shared lineage because you have already identified that section as coming from great-grandma so and so. More than intriguing to me. And seemingly so straightforward.
Until I started analyzing the results. And heard that lovely GPS voice in my head - rerouting, rerouting, rerouting. Here's what I've learned from the profiles I manage.
- Some folks spent too much time together over the last thousand years. If you have Ashkenazi Jewish ancestry ( ✓ ) you are going to match more people than you can imagine. I loved having genetic confirmation of our family tradition of Jewish ancestry. But the genetic noise makes matching people where I have a shot at identifying a common ancestor difficult. My new strategy is to focus on matches that are not shared with my cousins of Ashkenazi descent. That will either highlight the Slavic matches or suggest Ashkenazi ancestry on multiple lines.
- Acadian ancestry ( ✓ ) dominates results just as much as Ashkenazi ancestry. Lovely people. Lovely culture. But not what I am trying to investigate. My relatives need to be more considerate about their ancestors.
- As for those matches that do seem straightforward - think again. My mother's entrenched southern roots ( ✓ ) mean that we may share multiple ancestral lines. (Back to the folks spending too much time together.) It's glaringly obvious if I examine the data rather than focus on paper trails.
- Cousin A and I match. I match her father. We have an easily documented shared Williams/Pugh line out of southwest Virginia. But she and I share more DNA than her father and I do. Enough to make it clear that she and I are also related through her mother. No clue what that connection is. While I can make some assumptions that the matches I share with her father are the Pugh/Williams lines, I wish I knew what the others were.
- Cousin B and I also match and are confirmed Pugh/Williams cousins. But (and this is a big one) we are also X chromosome matches. My known Pugh/Williams line is not an X chromosome match. Not at all. So where does that X match come from? We are clearly related more than once.
Photograph from Flickr by Duncan Hull Some rights reserved.