ThruLines and Clusters and Snowballs

A Segment-ology TIDBIT

The process using Match Notes and identifying Clusters (see blog post here) has a snowball effect. Other Matches in the Shared Match list are more likely to have the same ancestry. Check this by clicking on one of those Matches (for whom you don’t yet have a Common Ancestor) and seeing if a lot of their Shared Matches form a Cluster – sometimes they do, sometimes they don’t. Focus on when they do! Focus on Matches who Cluster with several Shared Matches you’ve already connected with the same branch of your Tree. If the target Match has a small Tree, I have often been able to look at the tips of their Tree and recognize a collateral name from my previous research on my Tree branch. Or to find a location that leads me to research and extend a branch of their Tree. Or to add a few more descendants in my own Tree branch…

When a Match has several Shared Matches for whom you’ve already identified the same ancestral line, the probability is high that that Match will tie into the same ancestral line.

Snowball ThruLines to Notes to Shared Matches to Clusters to Common Ancestors with more Matches.


[22AN] Segment-ology: Use Match Notes from ThruLines to identify Clusters TIDBIT by Jim Bartlett 20190729

8 thoughts on “ThruLines and Clusters and Snowballs

  1. Pingback: AncestryDNA and Other Goodies (a test covering this will be given at the DNA Sig) | Monterey County Genealogy Society

  2. My ancestry is all from the UK, so I have a slight shortage of closer matches. But I set to work with what I have, using every tool and approach at my disposal. I am excited and pleased by the results. While I have not always identified the MRCA, I have come close in many cases and have a good idea of the time and place of connection as well as the history of cousin lines. I know now, for example, that over 50 matches are no closer than 10 generations in their connection to me and possibly even 13 or more. They have a long history in Colonial America dating back to the 1600’s. After much research, I can tie them all to one specific ancestor of that time. None of my direct ancestors left the UK. However, I have been able to use segment data to triangulate some of these matches with a couple of third cousins in Scotland, so I have an idea which grandparent lines may have had a sibling or descendant of a sibling who became pioneers in what is now Virginia and West Virginia. So, I can certainly vouch for making use of clusters and shared matches.


      • After posting here, I decided to move on to the next items on my list for this particular investigation. That item was to contact a project administrator or two for the prominent surnames in my project. I now see that you are the program administrator for the Underwoods. Small world indeed. There are many Underwoods in my project based on clusters and atDNA segments. In fact, I started with a small group of shared matches, examined their trees and expanded them and saw the name Underwood appearing in a few. As I expanded the trees along those lines, more names and places cropped up. So I started searching the match list for those frequent names and places and seeing if they had shared matches within the cluster but did not show due to being under 20 cM, beginning with Underwood as the surname and Virginia as a place. Eventually I had over 100 added to the group which was a good number to work with and find enough some with reasonable trees to start weaving them all together. It has been an exciting process of discovery.


  3. I do this using the colored dots. If I look at a new match and shared matches predominately show the colored dot for my paternal line, I can be pretty sure they are also on that side (same for a specific ancestor). It’s a judgement call, but my paternal and maternal lines rarely cross.


    • mcelreaons,
      I am also using colored dots (for TGs and CAs, etc.) My Notes point to specific lines, which is how I want to group in Clusters. From previous experience, I know that deep enough Clusters align pretty closely with Triangulate Groups. And I agree there is some amount of judgment involved. Jim


  4. Many(actually about half) of my matches – have no trees, private trees, or only have entered one generation) of “Living”folks.

    But I do find the Tru-Lines are helpful but I fear few of the users are even aware of the features.


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