I sat in on Legacy Family Trees webinar “Visualizing Ancestral Lines With DNA AutoClusters” with Ran Snir. It covered how to use the tool on MyHeritage for narrowing down which line your matches may descend from. The webinar was very informative and I feel I understand AutoClusters much more than I did initially.
AutoClusters Are Groups of Shared Matches
When you look at your AutoCluster report, it’s incredibly colorful and a intimidating. How is this report generated?
The simple answer is that an algorithm has been devised that goes through your matches. It compares each match based on how many centimorgans you share together on DNA sequences. Then, it groups matches together that it determines descend from a common ancestor.
Note that you have a few options as to how to order your report. Under “Order DNA Matches By” at the top of the report, you have these choices:
- # of Shared Matches
- Shared cMs with Tester
If you highlight names on your report, you can see who is in that cluster. All those people will have an ancestor in common. It’s your job to figure out who it is.
High Matches Are Excluded For A Reason
One of the things I wondered when I first reviewed my repost is why my closest matches are excluded from the report. After all, if I know how my mother or a first cousin is related, won’t that help divvy up my matches?
I thought this example was very helpful. Let’s say both your parents have done a DNA test. If they were included in your AutoCluster report, all you’d have is two clusters. One would be maternal and one would be paternal.
PATERNAL CLUSTER ……………… MATERNAL CLUSTER
While it’s nice to know what side of the tree a match comes from, you have several ancestors on each side. Does this person descend from your mother’s maternal great great grandfather or her paternal great great great grandmother? There’s no way to know if half your matches fit into her cluster.
They limit the amount of shared cMs to 350 cM so that you will have more clusters to work with. I have one cluster which includes two of my third cousins and a fifth cousin. The two third cousins share great grandparents with me.
The fifth cousin shares my fourth great grandparents, Manoel de Mello and Barbara da Silva. All four of us descend from this couple.
If anyone else joins this clusters, I’ve got a pretty good idea that they are going to descend from Manoel and Barbara or one of their ancestors. That’s so much more helpful than knowing they connect to my mother or my father.
If you want to see if a person in a cluster matches your closest matches, just go to their shared match page and see if the name is listed.
Grey Boxes Have Meaning
When I was going through my matches, I noticed grey boxes scattered around my report. These aren’t flukes, they are there for a reason.
When you see that two people share a grey box, it means that their shared DNA was inconclusive. Typically, this means that that share DNA with other matches that are found in different clusters.
Think of it as one of those crazy matches that appears to come from both sides or your tree or matches people on two different lines.
Scroll Down To See Your List of Matches
It can be confusing working from the grid. At the bottom of the report is a list of every cluster with every member in those clusters.
You see these categories:
- Shared cM
You can see total cM, the largest block, how many segments, what cluster they are in, and how many people are in their tree. they share, whether they have a family tree, and how many members are in that tree. You can also see if you have notes on this match. (I confess that I do not know what ICW means.)
You can make this section more useful by making use of the Notes field on your DNA match list. There is a little note pad icon in the right had corner of each DNA match.
If you know how your match is related, add a note like “3rd cousin, Pacheco/Achada side”. These notes will appear in the notes field on the AutoCluster report. Now, instead of flipping back and forth between pages, you can easily see if you’ve figured out a match in a group or if you have some inkling of where they might descend from.
Endogamy Will Be A Factor
You may have heard this term in relation to genealogy. Basically, it means there’s a whole lot of intermarriage going on. You typically see this in small communities and villages where the families have intermarried over generations.
It creates what I refer to as a tree implosion. This is when your ancestors marry your other ancestors.
If both your parents come from the same village, it’s likely that you have at least one set of the same ancestors on your paternal and your maternal side. For instance:
Your paternal great great great grandfather is from family A and married into family B.
Your maternal great great great grandmother is from family B and married into family c.
Your maternal great grandfather marries someone from family A.
This confuses AutoClusters as I am sure it does every other DNA tool. I know it confuses me.
I’m Still Unclear About How the Triangulation Tab Differs From AutoClusters
After listening to the webinar and reviewing my report, I am unclear on how the AutoCluster report differs from the Triangulation tab.
My understanding of triangulation is that these people share at least one DNA sequence within certain parameters. In the example above, I told you that I have 3 known cousins in one cluster group. However, when I review them under shared matches, they do not have the triangulation tab. When I compare their DNA, I don’t see similarities. Yet, I know that they are related and how.
To confuse me further, other people in the same group of shared matches do have that tab. However, they do not appear in the cluster with these known matches. Why is that?
I guess I don’t understand how these two tools differ. They both seem to be looking for shared DNA sequences. So, how does this algorithm differ from triangulation?
You Should Run Your Report Every Few Weeks
I hadn’t really thought about it, but the more people who test, the more people there will be to compare to. You’re going to have to run your report about once a month depending on how many new matches you get so that your report is up-to-date.
Also, MyHeritage tinkers with the algorithm used to determine clusters. I suspect the results will become more refined over time. They may add new features that will make it easier to interpret the results as well.
So, run a new report every so often to catch new matches and to see what’s been modified on the report.
All in all, this was an excellent webinar. It was informative and gave me a better idea of how clusters might help me resolve my matches. For a limited time, you can watch the webinar for free.
This is an informative book that helps you understand your DNA results.
Now, if I could just get a Jackson cousin to test at MyHeritageDNA, and then, get some solid matches who have Jackson in their tree, I might figure out who the heck Harry Kenneth Jackson descends from. Oh, the Portuguese and French are so much easier to work with!