Back in the early days of DNA at Ancestry, there were DNA Circles. According to the Circles White Paper, (no longer available on their website), “a DNA Circle™ … is created by combining pedigree and IBD information from across theAncestryDNA member database.”
Next came ThruLines® which also combined pedigree information with match data.
The caution with both approaches is the combination of DNA information, derived from a technical process, with pedigree information, derived from fallible human processes.
The addition of Enhanced Shared Matching in 2024 gave Ancestry users with the ProTools subscription the ability to do much more powerful analysis of their matches. (Notably, this feature had been available at every other testing site prior to 2024.) The shared cM amount between shared matches increases the number of matches that can be placed into speculative trees which can be validated at BanyanDNA. Since Ancestry has the largest database of DNA testers, this opened many doors for genetic genealogy.
Autoclustering has been available at MyHeritage for many years. A clustering tool is available at GEDmatch and other third party services have offered clustering for years. Now Ancestry has given ProTools subscribers Matches by Cluster. Clustering relies on genetics alone, grouping matches who share DNA with each other. The genealogist then uses that information to determine which ancestor the cluster may be associated with. This is the best use of DNA – using it to point to where to look for documents to explain the relationships between the matches.
Tips for working with clusters:
- Understand who is included in the clusters and why. Read the FAQs on the Ancestry Matches by Cluster page.
- Take a good luck at the cluster and know what you are seeing. Your matches appear in a list in the same order along the side and across the top. You are the light tan background. Coloured squares indicate where your matches match each other. The dark multi-colored diagonal line indicates where your matches match themself, giving you a useful point of reference. Darker grey squares that are outside of a cluster indicate where your match matches someone not in the main cluster. An algorithm decides who goes in what cluster. This darker grey “confetti” can indicate useful information about how the clusters might be associated with each other, for example, a generation further back, a more recent generation, or multiple relationships. Note: clustering is not as useful for people who have endogamy in their family. There are ways to adjust clusters, and Ancestry says this ability is coming soon.
- Identify Most Recent Common Ancestors for each cluster. Look at the trees and search for surnames, and/or locations, and/or times in common. I often take a screenshot of the clusters and then annotate them as I determine the MRCA.
- Build a tree based on what you’ve learned and validate it on BanyanDNA or by analyzing shared DNA amounts and relationships individually.
- Write down what you’ve discovered and then use it to do documentary research. Revise your summary after your documentary research.
- Set up a routine to repeat the cluster analysis as the database grows.
Have fun with the Ancestry Matches by Cluster tool!