Thursday, September 22, 2022

Rabbit Holes With Randy - Genetic Affairs AutoClusters

 This week's rabbit hole was to run AutoClusters on Genetic Affairs ( for my 23andMe, FamilyTreeDNA and MyHeritageDNA match lists.  I do this about twice a year, and I probably need to do more investigation of the other features on Genetic Affairs.  In addition, I needed something to discuss in some detail in the Chula Vista Genealogical Society DNA Interest Group meeting on Wednesday, 21 September 2022.

1)  I focused on my 23andMe matches for the CVGS meeting because I have some mystery matches there and I knew that the AutoCluster analysis would help me narrow the In Common With of my high value matches on 23andMe.  I have "only" 1,523 DNA Matches on my 23andMe test, with a minimum value of about 30 cM  because I haven't paid extra to see more matches.

The results of my 23andMe AutoCluster analysis is:

I set the maximum cM value at 250 cM and the minimum value at 30 cM.  I had 146 matches that could be put in a Cluster, and 22 clusters of 2 matches or more.  So now I know that I have 8 matches in Cluster 1 and 3 in Cluster 2 and 2 in Cluster 3 and 10 in Cluster 4, and so on.  If I know how I'm related to one person in the Cluster, then that is a clue that the other matches in the Cluster are related to me through one of the ancestral surname of my known DNA Match in the cluster.

In addition, the AutoCluster spreadsheet provided shared cM values of my matches, and of each match in a cluster with other matches in the cluster.

In Cluster 1, I know how 5 of the 8 DNA Matches connect to me, and with each other (with some exceptions).  For Cluster 1, this is a Richmond related cluster.  I can use this information to narrow the search for how I am related to the other 3 matches in this cluster.

The shared match information in each Cluster may reveal relationships between each person in the Cluster.  For instance, in Cluster 3, which has only 2 matches, but they share 3517 cM, so this is a parent-child relationship.  This is really useful information, as is sibling relationships in the 2500 cM range, and aunt/uncle relationships with about 1800 cM.  

3)  I have matches with a known common ancestor for several clusters.  Cluster 1 (a Richman/Marshman 3rd great-grandparents line), Cluster 4 (Kemp/Sovereen 2nd great grandparents line), Cluster 5 (also a Kemp/Sovereen line, but a different descendant than Cluster 4), Cluster 18 (a Spangler 2nd great-grandparents line), Cluster 19 (a Carringer/Feather 2nd great-grandparents line), and Cluster 22 (a Cutter/Randolph 4th great-grandparents line).  I don't see a known descendant of my Seaver, Hildreth, Sawtell, Rich, White, Oatley, Smith, Vaux, Auble, or Knapp 2nd great-grandparents lines.  They may be hidden in the other clusters that I haven't identified yet. 

4)  The only drawback to the AutoCluster information is that it finds only those matches in the 30 to 250 cM with other matches in the Cluster.  It doesn't find DNA matches that are not in a Cluster of 2 or more.  Hence, it worked, in this case, for 146 matches out of 1,523.  But they are, in the main, high cM value matches, certainly cousins of mine.

5)  I also did the MyHeritage and FamilyTreeDNA AutoCluster analyses, and each of them has a different set of DNA Matches to work with.  There are some duplications of Match names on one or more of the four largest DNA test/analysis companies.

6)  We had about 30 attendees in our DNA Interest Group on Wednesday, and I  think only one of them have used the Genetic Affairs AutoClusters.  Only a few of them have done a 23andMe test.  There were very few questions about AutoClusters, so I'm afraid I info-glutted many of the attendees, but maybe my presentation will encourage others in the group to use it.

7)  I spent about 8 to 10 hours doing all of this in the past week.  I found out that I know very little about using this tool and it showed in my presentation.  

I need to find my carrots to build up some energy for working with the FamilyTreeDNA and MyHeritageDNA clusters.


Disclosure:  I paid for my 23andMe autosomal DNA test in about 2010.  I subscribe to Genetic Affairs for $5 a month so that I can do as many AutoCluster analyses as I want.

Copyright (c) 2022, Randall J. Seaver

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