One of my DNA matches, Katherine, is a descendant of my ancestor, Samuel Sargent. Her tree indicates that she descends from the same Samuel Sargent that I do. To be certain she and I were actually related through Samuel Sargent—and that there was not some other shared ancestor I simply had not located on her tree—I looked at the shared matches I had with Katherine.
I looked at what I am calling Katherine’s pool of matches. That pool consists of each of her matches and the shared matches have with those matches. If the majority of Katherine’s matches also descend from Samuel Sargent (or someone reasonably connected to him on my genetic tree) then I’ll feel pretty certain that I’m correct in concluding that the genetic connection I have to Katherine is through Samuel Sargent.
Katherine’s pool was created from the five matches she shared with me.
Tyler—No matches I share with Tyler are already identified to a specific connection to me. Matches of matches were also unidentified, but two matches did have the surname of Dingman which was the maiden name of Samuel’s daughter-in-law who is my ancestor. That may be a coincidence.
Alexia—First shared match with Alexia was a descendant (LOT) of my great-grandparents—those in my line of descent from Samuel Sargent. Second shared match with Alexia was a known descendant of Samuel Sargent. Other 15 shared matches with Alexia have connections that are unknown but they all had LOT as a shared match consistent with a Sargent connection.
William—William’s genealogical connection to me is unknown. William’s first shared match was another descendant (GIH) of my great-grandparents who are in my line of descent of Samuel Sargent. Another of William’s shared matches with me had LOT and GIH as shared matches. Another of William’s shared matches is a known descendant of John Powley whose granddaughter married a son of Samuel Sargent. The other six shared matches could not be determined.
Michael—Two of Michael’s shared matches with me are known descendants of Samuel Sargent.
Fred—One shared match with Fred is a known descendant of Samuel Sargent. Seven of the other eight matches are names that appeared in the shared matches I had with the other matches I shared with Katherine. Then there was Vicki.
ThruLines pegged Vicki as a descendant of my ancestors Johann and Elska (Fecht) Janssen. Vicki’s short tree only extends to her grandparents, but I didn’t need ThruLines to tell me how she was related as I already had her grandparents in my database. The amount of shared cM she and I have are consistent with that genealogical relationship. Confirming the relationship with Vicki was the fact that the first six matches on our shared list of matches are individuals I have already documented as descendants of Johann and Elska (Fecht) Janssen—including two of my Mom’s first cousins.
Here is why Vicki matters and why the analysis of your DNA results is not always as simple as it appears. I have many families who overlap geographically. Physical proximity of families means that in some cases my DNA matches and shared matches with those matches can be confusing because of multiple relationships or matches of mine sharing ancestors with each other that I do not have.
Then there is Vicki’s genetic connection to me. She’s a shared match with several of my Sargent matches, but her ancestral connection to me through the Janssens is closer (a set of third great-grandparents) than my connection to Katherine and the other matches I share with Katherine. The connection to Vicki is also in a different geographic location: Ostfriesland, Germany, via Hancock County, Illinois. Even if I had been unable to determine the relationship with Vicki based upon her tree, her shared matches told me that she was not a Sargent descendant. She has entirely too many matches with my maternal families.
The Sargent family in my background did not marry into my extended set of Hancock County, Illinois, families until 1898 after arriving in the county in 1880. My other Hancock County families lived in two general parts of the county and many had been neighbors back east or in Europe. The Sargent family was the exception.
Vicki and I only have one shared segment of 21 cM of DNA.
Somewhere, at some point in her tree, Vicki probably had an ancestor who is also an ancestor of some of my Sargent relatives—but is not an ancestor of me. It is possible that Vicki and I have more than one genealogical connection. My suspicion is that Vicki is related to a small subset of my Sargent DNA cousins.
When you look at that list of shared matches you have with a match (particularly once you get past second or third cousins), do not assume that they all have to be related in the same way or even through the same general family. There could easily be the occasional shared match with a match who is related to you in a different way.
That match you cannot figure out can be an outlier.
Many Katherines have a Vicki.