Monday, August 1, 2011

Genetic Testing, what to do after 25 Markers

Louisville Remembered (American Chronicles)
I was working with a project member this morning who had done 25 markers and was looking for how to make sense of the match.  Here's what I told him, information that will be helpful for everyone:

I see that you have only tested 25 markers. You have 16 exact matches at 12 markers. While you are related to all those matches, they could be relatives prior to the last 700 years, when surnames came into existence. Thus, 12 marker matches do not mean much, unless you already know for sure (through a paper trail) your relationship.

At 25 markers, you have one match at a genetic distance of 1. This, again, does not mean much. Your match, Michael X*, has tested at 67 markers. So, you probably ought to upgrade your testing to 67 markers to see if you are still just one marker off an exact match, or if the match falls apart.

Here are two additional strategies you can try. Through your documented family history, find another male Taylor from your line (as distant a cousin as you can prove is your relative) and have him test. At that point, he will either match you closely (65, 66 or 67 or 67 markers), or not. If you do not match, then the paper trail is not accurate, and one or both of you descend from a line of a different male progenitor than is indicated on your genealogy.

A second strategy is to do the Family Finder test. Here you are matching autosomal DNA, matching across all family lines. While I am excited about this DNA test, and have done it for two of my Taylor and one Robinson relative, the matching is difficult so far because the people I've matched have not responded with their genealogical information. I'm not blaming them, as the protocol for how to work with others in matching autosomal DNA is not developed and many of them may be clueless. So, the science of autosomal matching is definitive, but the cooperating with one another to discover how we are related is in its infancy.

I hope all this is helpful. Please do more y-DNA markers, at least 67. Then consider the Family Finder test.  Together with the Taylor team, we should be able to assist you with your genetic matches.

*Complete name not give for reasons of privacy.
Note: the image is a Taylor important in the history of Louisville, Kentucky, whose name I did not get.

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