Everyone is posting pretty cluster pictures like the one below that I made for my perfect cousin, the star of many of my blog posts. This is a table where each DNA match is listed on the top and side; then if they match each other, the box is colored in with the color for that cluster. The chart is sorted by cluster. The idea is that each colored cluster shows descendants from a probable great grandparent couple of yours.
The gray boxes show where people match others outside the cluster which can often happen when families intermarry more than once or when they are first cousins enough times removed to have been in the second or third cousin group by DNA but are related to more than one set of great grandparents.
Automated clustering is useful because it puts your DNA relatives who are related to each other into visual groups so that you can quickly see which line a new match is related on. The picture is pretty but the workhorses are the charts for each cluster shown below that image when you scroll down. Here is the privatized one for my “perfect” cousin showing our MUNSON cluster.
Each name can be clicked to go to that Ancestry match page plus much useful additional information is shown next to the username: how many cMs shared, how many matches shared in the whole group, cluster number, how many people in their tree, and the notes you made for that match.
The image and charts are from the HTML file which arrived via email from Genetic Affairs after I requested automated clustering for my cousin’s Ancestry profile, which is shared with me there. You have to save the html file to your computer and then click on it to view it. When it first comes up, it is a mish-mosh sorted by name, but then it resorts itself by cluster. Fun to watch. Click here for the step by step of how to use this tool from the Intrepid Sleuth. It can also cluster matches from other sites like 23andme.
I decided to try it on an unknown father case I had not gotten around to working on yet, to see if it succeeded in speeding up the process and it did, to under an hour! A new record.
To be fair this was a case where the maternal side was well known and documented and all ancestors have deep American roots. Jack had tested to help his maternal half brother Everett find his Dad but initially had no interest in pursing his own bio dad connection (all names are changed as always for privacy). Recently he decided that knowing his paternal family medical history might be worthwhile so he gave me the go ahead.
I always knew that Jack’s search would be quick given that on his unknown paternal side he has 4 second cousin level matches and 18 third cousins, many with deep trees. This is way more than the average tester! Here is his automated cluster picture:
The names down the side of the page have been blurred out but I could see them and I was immediately struck by the appearance of a specific surname in half the usernames on that big cluster. I knew I had seen that surname in his best match’s tree, a first to second cousin, let’s call her Kate, who is too close to be included in the clustering.
Next I looked at cluster 2, also paternal, in the charts and saw that many of them had good sized trees. So I clicked the three top matches from the charts with trees and took a look at them. Again, one surname stood out.
Now can I find someone with surname1 marrying surname2? Those would be his paternal grandparents. Since Kate has a huge tree, I decided to search her tree for that second surname. There were only a few and just one was married to a woman with surname1. Plus they are the right ages to be his grandparents. How quick was that!
Next I build him a quick and dirty (Q&D) tree using Kate’s tree, green leaf hints, and those green “Potential Mother/Father” things. Connected his DNA as the son of an unknown son of the presumed grandparents.
While waiting for Ancestry to find those DNA ancestor hints, I decided to spot check if the expected relationships agree with his new tree for the relatives in the two clusters. So I clicked through from the charts to each clustered match with a tree, looked where the common ancestor was, and put in the note for that match what the expected relationship now is. I also checked each one in the DNApainter calculator to see if the theory fit. So far so good.
The next step is to try and figure out who the son(s) of this couple are. Usually that is via an obituary but I did not find one. So I reached out to a close relative on each side to ask and explained why. We will see if they respond. One logged in yesterday and has a huge tree so I am hopeful.
To summarize, the picture is pretty but the charts are an incredible time saver because I can see which matches have good sized trees and can click through to them to test my hypothesis. Not every adoptee will have such robust clusters so as to easily find the surnames of each grandparent, but hopefully some will.