DNA Case Study: Hayden Family

So far, my typical DNA connections consist of picking a DNA match and trying to piece together a family tree that connects to my own. This is sometimes successful. Sometimes I ask for help from the DNA match, who sometimes replies. It usually involves lots of work. And as I continue down my list of DNA matches, toward more distant relations, it gets harder and harder.

My Hayden family connection was different. While exploring match profiles on 23andMe, I noticed several that seemed grouped together, frequently showing up as common matches. Almost all replied to my messages. Almost all had researched their genealogies extensively. I fairly quickly established that the common family was the Haydens. Some put me in contact with other Hayden family genealogists. One had attached resources to a Hayden tree on FamilySearch, and also replied to my message. After gathering their information and researching the gaps, I was able to assemble a skeletal family tree, just connecting the DNA matches, not including their families and ancestors families that I have typically included in my tree. I then tried to connect my own Hayden ancestor to their tree. No census records together, no Irish baptismal record, no FamilySearch, Rootsweb, message board, FindAGrave, Google, or other public data information. None of the matches had among their records any mention of my ancestor.

Anne Hayden Campbell

One of my matches referred me to an article they had written many years ago in which I recognized a photograph that had been hanging on my parents' wall for decades, in what they called the "Rogues Gallery", their photos of their ancestors. While my match had guessed at the the identity of the person, ours was labeled Anne Hayden Campbell by one of Anne's grandchildren. So although I was not finding the family connection, this photograph implied that there was a connection and that most likely their Hayden family was my own.

Now I wondered, if my Anne was part of this Hayden family, where would she fit in? All of the others traced back to Martin and Katherine Headen, born in 1796 and ca. 1790, respectively, in Ireland. The baptisms of many of their children took place in the Catholic parish of Myshall in County Carlow, where records state the family lived in the town of Shangarry. The known birth dates were in 1817, 1822, 1825, and 1832. Anne was born between about 1823 and 1826, so would fit nicely into an unusual gap in children. Baptismal records in those early years were infrequent, so she could simply have been missed. But Anne could also have been Martin's niece, in a different branch of the family.

Now I turned to DNA. The amount of DNA shared with matches was about right for Anne as a daughter of Martin. But there can be quite a bit of variation in inherited DNA, so I was not comfortable placing Anne in this tree based simply on shared DNA. Yet. So I constructed the following chart. It requires some explanation.

Hayden DNA Comparison Chart

I identified fourteen DNA matches to my parent on 23andMe who were likely related through the Haydens. Of these, I could place ten on a Hayden family tree. In the chart above I recorded in the lower half the relationships between all these cousins as read from the tree and added average amount of DNA that should be shared between these cousins, if only a simple single relationship exists. 3c-2/0.2 , for instance, is third cousin twice removed, who share an average of 0.2% of their DNA. The four empty lines are the four persons whom I could not place in the tree, and so with whom I cannot know their relationship with the others. In the upper half I recorded the estimated relationship and the measured amount of shared DNA as reported by 23andMe. The columns/rows of x's are Hayden descendants whose DNA was either not analyzed on 23andME or who did not show as a match to my parent. The gray boxes are where DNA matches were not detected/reported, even though both were matches to my parent. Finally, I color coded the results. Basically, green shows 23andMe estimates close to true relationships, "red" (purple) not close, and yellow somewhere in between.

First I compared just the matches among themselves. Now I'm down to eight matches: started with fourteen, four I couldn't place in the tree and two did not show up as a match to my parent. Among these eight persons, there are twenty-eight relationships. Of this twenty-eight, eleven (39%) don't show up at all. This is typical for 3rd/4th cousins. Of the seventeen that do appear, eight (47%) are good/green, six (35%) are so-so, and three (18%) are incorrect. Note that by "incorrect" I mean percent shared DNA is different from what I expect by a factor of two or more. This is only half a generation, or, say, the difference between 4c and 4c-1 (fourth cousin vs. fourth cousin once removed). This may not be a huge error, but it is important in determining where Anne might fit into this tree. So the above numbers, % good numbers, are my baseline.

Now I look just at my parent's relationship with the other eight. In order to have relationships from the tree, I have to place her somewhere in the tree. I placed her as a child of Martin and Katherine. There are eight possible relationships. Of these, none did not show up. That's obvious, because those that don't show up are not visible in my results. Actually, I later discovered that one of the persons who did not show has had her DNA tested on 23andMe, but can't find me among her matches, either. Of the eight that are visible, 50% are green, 37.5% are yellow, and 12.5% are "red". I think these compare very well with the 47%, 35% and 18% baseline. My conclusion is that my ancestor, Anne Hayden Campbell, is the daughter of Martin and Katherine Headen.

Now I need to go back and fill in all those quick-and-dirty sources I noted while assembling a family tree ...