July 24, 2020
By now I’m sure everyone has heard about the upcoming changes to the way Ancestry lists DNA shared matches. Ancestry released a white paper discussing the changes to their system, and there have been numerous blog posts by movers and shakers in the genealogical community such as Blaine Bettinger, Roberta Estes, Diahan Southard and Judy Russell. Unfortunately for the DNA dabbler like me, the posts range from “this will destroy genealogy as we know it” to “no big deal for the average genealogist.” This isn’t particularly helpful for those like me who are casual DNA users. We’ve taken two or three DNA tests at various vendors; we’ve read a few books and attended lectures on using DNA to solve genealogical problems. We’ve looked at our match lists and figured out how we are related to most of the closest matches. We’re slowly wading into the deeper waters of DNA research, so what do the new changes mean for us?
It appears that the change that will directly affect most of us and is causing most of the uproar in the genealogical community is the fact that Ancestry will no longer be showing us matches who fall below 8 cM of shared DNA. Until now the threshold has been 6 cM, so a number of matches will be disappearing from our lists when the new system debuts sometime in early August. According to Ancestry, as many as two thirds of these small segment matches are “false matches” – people who don’t really share valid DNA matches with us. Most of the rest of these small segment matches are from common ancestors so far in the past, often twenty generations or more ago, that they are beyond the reach of most pedigrees. For these reasons most genetic genealogists recommend that beginners in DNA research concentrate on matches who share at least 20 cM, especially since there are literally tens of thousands of these small segment matches on many of our match lists – way more than we can even begin to work with.
Most of us won’t even miss all of the those small segment matches on our lists. However, there are some situations, such as African American research, where small segment matches can be useful so Ancestry is letting users keep these small matches by attaching a note in the note field, adding them to a group, messaging them or adding a star. This is why we hear of some folks madly trying to sort through thousands and thousands of these small matches to “save” them. However, the consensus of the articles I’ve read seems to be that most of us probably don’t need to bother to save more than a few of these small matches. For example, I have a few surnames on my tree that have proven difficult to research. I have made a group for each of the names and have added any small segment matches I’ve found to it. The truth is that I may never be able to figure out where and how these folks fit, if they do, into my family tree, but at least I’ll have them saved – just in case.
Otherwise, most of these small matches have no family trees and little information to help me even figure out whether they’re valid matches. I’m not going to spend time worrying about them disappearing; I still have plenty of closer matches to focus my limited time and resources on. If you would like more information on Ancestry’s new matching system, Randy Seaver has a post at is blog Genea-Musings called “Ancestry DNA Changes Coming Soon – What I’m Doing” that may be helpful. You can find it at geneamusings.com; the post was published on July 20, 2020.
Researcher/Director at Large