Wednesday, January 4, 2017

Ancestry DNA and Making the Most of Matches

I wasn't really sure how  DNA testing could help me extend my genealogy until recently. I've got some ideas, now, on how to approach it.

Ancestry DNA reports people who have matching DNA to you. They simplify the analysis so we don't need to be DNA experts. Based on the amount of DNA we share, matches are given a predicted relationship range. I have found these to be fairly accurate. I can make a good guess as to whether it is great grandparents, or great great grandparents, that we share. And if a tree is provided for the match, sometimes I can identify the family, or even the ancestor we share. But there are thousands of matches. Where does one begin?

Genealogy is always about working from the known to the unknown. It is the same with this. Take things step-by-step. Start with the best matches. These are the ones that have known common ancestors. They show up as "hints" in the list of matches. Ancestry allows you to filter them. Besides their tree, they each have a set of matches that you share. These matches are all on the same family line, perhaps a few generations back. Sometimes they will have a tree, which confirms this, and helps pinpoint your relationship.

First thing I did was to make a circular pedigree chart with mostly blank space, I added surnames in the spaces provided, leaving as much blank space as possible. Then I went through all the best matches, looking for the appropriate space on the chart. I found that the cousin level for that match corresponded to the generation on the chart, making it easy to plot the match in the right generation. When I was certain of the relationship, both family and generation, I put the match on the chart in ink.


Some matches pose a bit of a dilemma. These are matches with fairly complete trees, but no obvious common ancestry. Since these matches do have trees, the map of locations that ancestry provides for matches can be helpful. These seem to be matches for your dead-ends. Maybe the surname of a female ancestor is not known, or maybe its from a first marriage, or changed for some other reason. I think this is what I am seeing with my Salucia Sophronia Clark line. I see a group of people who match a Squibb/Clark 3rd cousin and myself, but not some of the known Squibb 4th and 5th cousins. They may be my "Clark"s. Or they may be her husband Robert Squibb's mother's family. also a dea-end. I have one group of matches with 25 - 30 centiMorgans of DNA match which could be 3rd, 4th or 5th cousin. There are charts with this information. This is probably the most technical piece of information that Ancestry reports, and it is buried a bit. Click on the information symbol by your matches confidence level, and it will report this. I don't think Ancestry considers it essential, since they give you an estimated relationship.

Most matches just don't have trees. Sometimes its for privacy. I have already uncovered two adoptions in my very extended family that are understandably sensitive issues. Usually, I think it is because people don't see the advantage in sharing this information or don't know much about their specific ancestry. Most just want to see their heritage report.

But even these matches are useful. Digging deeper, by looking at the matches you share with them, will add to your knowledge a bit. Based on the relationship with other matches, and the reported generation, you can plot these matches on the chart as well. But use pencil. There are too many uncertainties with these, since you don't have a proven relationship, neither family nor generation. Eventually it will all come together, maybe with more work on your part, or in time as more people submit their DNA tests to Ancestry.

Another thing I've explored a bit is downloading my raw DNA file from Ancestry. This too, is a bit hidden, being in the settings, but it is available. Other services accept this file and do their own analysis and matching. Some are even free. Most are a bit more technical than Ancestry. Gedmatch.com takes the Ancestry DNA and a tree and can be used to report matches as well, but with chromosome number and location of common DNA. At this point I haven't found a good use for that, but it is early in my learning process.

Bob Mesenbrink
January 2017


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