An Analysis of My Mom’s Shared Clusters

I’ve been playing around lately with John Brecher’s Shared Cluster Program. I wrote a series of three Blogs looking at my owned Shared Clusters. The last Blog is here.

Downloading My Mom’s AncestryDNA Matches

First I signed into my account using the Shared Clustering program. I chose my mom’s kit and downloaded it.

I used the middle button which says ‘Slow and complete’. It was supposed to take several hours but only took 32 minutes. My mom has 26947 total matches and 438 fourth cousins. That is about half the matches that I have.

First Try: 50 cM Gets Two Clusters

My first try was conservative at 50 cM. I only got two clusters. I was sure to name the output file indicating that it was for 50 cM:

This gave me two named clusters. I say named, because I see that there are probably actually four clusters altogether. My guess is that these represent her four grandparents. The top cluster represents my mom’s mom who was a Lentz.

By the way, my analysis looked like this:

I have a green box around my mom’s side. I will be expanding that like this:

For now, I’ll keep it simple with a paternal and maternal side for my Mom:

3 Clusters at 40 cM

These clusters are in no hurry to separate. That is partly due to my mother, her niece and two grand-nieces being in Cluster 3:

One person I know in Cluster 2, Otis, descends from a Schwechheimer:

Also Gangnus, but more distantly.

At 35 cM, Mom Has 6 Clusters

Now my mother’s maternal grandparents, Lentz and Nicholson are starting to separate. Nicholson is Cluster 2 and Lentz is Cluster 4:

Here is a simple comparison of Clusters between the 40 cM and 35 cM cutoffs:

This shows that the Lentz 1900 went to Lentz and Nicholson as I have them. That means I need to figure out where Clusters 1 and 6 go. These are new clusters with no precedent. All three in Cluster 1 match my mother’s Rathfelder cousin, so Cluster 1 could be Rathfelder or Gangnus:

Cluster 6 also appears to be on my mother’s father’s side which could be Rathfelder or Gangnus. I’ll put them under Gangnus as I have nothing else there so far.

My Mom’s 10 Clusters Down at the 30 cM Match Level

My MS Access query gives me this:

At the 30 cM level, this shows that Clusters 3, 6 and 10 are new. The previously new Clusters 1 and 6 at the 35 cM level map to new Clusters 9 and 1. Cluster 7 is interesting it has no precedent at the 35 cM level but one of those non-precedents was previously a Cluster 2 (Scwhechheimer) at the 40 cM level. So that may be a clue. Here is how these 35 cM clusters map at the 30 cM level:

Three maps to 8 and 7. 5 maps to 2. Technically 5 did not map to 7 but someone who was in the precursor to 5 mapped to 7. This probably gets into intermarriage in the German colony of Hirschenhof, Latvia where some of my ancestors lived. I suppose I could have omitted the second 7. Here is Cluster 7:

It looks to have two parts to it.

That leaves Clusters 3, 6 and 10 to map. Because I compared the clusters above in Access, I didn’t have to know anything about who was in the clusters when I mapped Clusters 1, 2, 4, 5, 7 and 8. However, for Clusters 3, 6 and 10, I have to know something about these people to put them in the right places.

Finding a Home for Cluster 3

Cluster 3  at the top left is part of a larger Cluster 3-4-5 complex:

The is a large area below the second green box which can be ignored as that would be my mother’s close relatives. The second green box is Lentz. Below the close relative area is Nicholson. One person in Cluster 3 matches 2 people in the Lentz Cluster. However, 3 people in Cluster 3 match people in the lower right Nicholson Cluster. So I’ll say this is a Nicholson Cluster. The Nicolson’s came from Sheffield, England. One person in Cluster 3 has a tree. This tree shows both of his parents being from England.

Cluster 5 – Consider the Source

Here I have both Lentz and Nicholson mapping to Cluster 5. How does this make sense? The ones that map from Lentz (4) to 5 are my mom’s close relatives, so naturally, they would match both sides. I’ll take the Cluster 5 that comes from Cluster 4 out. That is one of the disadvantages of mapping the numbers without considering the source.

Cluster 6 – Rathfelder Side

Here are my notes on this small Cluster:

My Rathfelder grandfather was a German from Latvia. So by geographical phasing, that puts Cluster 6 somewhere on his side.

Cluster 10 – Mystery Cluster

Cluster 10 has strong internal matches indicated by the dark color of the Cluster. However, I don’t see any other matches with other groups or clusters:

Two of the matches have large trees of over 25,000 people. Comparing my mom’s tree and this large tree brings up the name Clayton:

However, JK also shares these areas of ancestry with my mom:

Here I have banished Cluster 10 to the Unknown Realm:

So now I am ready to dive into new depths of my mother’s clustering ancestry.

Mom Is Up To 18 Numbered Clusters at 25 cM

25 cM is the next to the last stop for our analysis. This is an important level, because at this vantage we can look toward the more recent 30 cM clusters and will be able to look next at the further in the past 20 cM clusters. The progression for the numbers of clusters has gone 2, 3, 6, 10, and now 18.

This is the overall shape of the 18 clusters

My mom’s close relatives have split into two clusters. The previous Cluster 10 of unknown origin is getting bigger.

Putting Access to Work Again on the 25 cM Clusters

I imported Columns A-L to Access and added it to my ongoing query:

When I view this query, I get this:


I’ll sort by new clusters to see which ones are new:

Next, I’ll map the non-highlighted new clusters. Here is what I get with my blind comparison:

Clusters 7 and 8 are on my mom’s maternal and paternal side. I suspect that is a result of her close relatives matching both sides. I’ll search Access for Clusters 7 and 8 and add names:

Here I see Cluster 5 going to Cluster 8 only with two close relatives, so I’ll remove that from my analysis.

However, we are still left with two Clusters 7. One is on my mother’s maternal side and one on her paternal side. That means that Cluster 7 is a compound cluster due to close relatives being there and matching both sides:

That means my mom actually has at least 19 Clusters at this level:

Ancestry uses 20 cM for a fourth cousin cutoff. The fourth cousin level represents 32 ancestors – in theory.

Next, I just need to go down the Clusters and fill in the blanks:

Clusters 1 and 2 – Sheffield Area

One person in Cluster 7a matches all four people in Cluster 1. Cluster 2 goes back to a known Nicholson ancestor born in 1765. That would bring Nicholson down to 1798 on my mother’s line in the next generation. Due to the fact that we know that ancestors, it is possible that Cluster 1 could be on Nicholson’s wife’s Clayton line:

 Cluster 3 Affinity to Cluster 7b

Cluster 3 also has an affinity to Clusters 4 and 14. That brings up an error in my Chart:

At 35 cM, I had both Clusters 3 and 5 mapping to Cluster 4 at 30 cM. A review of my Access query shows one to be wrong:

Cluster 3 only mapped to Clusters 7 and 8. Here is the corrected version:

This is bound to be a little messed up because my mother’s father had Gangnus and Schwechheimer on his paternal and maternal sides:

 Cluster 5

Fortunately, I have already done some work with Robert in this Cluster:

Here is a confusing tree. The confusing part is that the common ancestor is with Gangnus. Gangnus is also the wife of my mother’s Rathfelder grandfather. That means that this Gangnus goes in on my mother’s non-Gangnus side!

Actually, it appears that Robert is equally related on both sides:

In fact, as Otis is not in Robert’s shared group, I need to put Robert back on the Gangnus side. Good thing I’m flexible. Patrick doesn’t figure in as his results are on MyHeritage.

I needed someone on the Gangnus side that I could identify.

Summary of the 25 cM Clusters

Here I dumped more new clusters into the Unknown bucket. I don’t have much under Lentz, so some may belong there.

The Final Run of 20 cM for 36 Clusters

I run this at 6 cM which is the minimum, but the minimum shared matching at AncestryDNA is set at 20 cM. Some of the extra matches between 6 and 20 cM could give hints from the Correlated Cluster Column.

Probably the easiest part of the comparison is using Access. Here is what I can fit out of the 83 rows of results:

Here is what the mapping looks like except for Clusters 7a and 7b:

Both Clusters 10 and 5 mapped to Cluster 24. That probably has to do with the interweaving of Schwechheimer and Gangnus in my mom’s Colony of HIrschenhof ancestry. In order to map Clusters 7a and 7b, I bring in the 30 cM clusters to see which 7 I am looking at:

Here, Cluster 2 maps to 7b and Cluster 5 to 7a. This still gives some confusing results:

However, when I filter out my Mom’s close relatives of over 900 cM, I get this:

Here is how that looks in my summary chart:

I couldn’t decide whether to put Cluster 12 in under previous Cluster 7b, so I put it in parentheses. It looks like I mapped 19 clusters not counting those mapped more than once. That should leave about 17 more to map – or drop into the unknown bin.

Mapping the New 20 cM Clusters

Here are some new clusters:

All I have to do is to look at each of these clusters. My best hope is if they match another cluster or have a common ancestor or if I have some notes on them in Ancestry. Occasionally, looking at a tree or building out a tree will help, but I rarely have luck that way. One thing I find difficult is that my mom had German ancestry on both sides. One side came to the US before the American Revolution. Another side went to a German Colony in Latvia and then came to the US in the 1900’s. However, both sides were originally in Germany.

Clusters 28 and 29

Someone in Cluster 29 had a Nicholson ancestor, but it may be coincidence:

Sarah was from Bolton in the above tree. My mom’s Nicholson’s were from Sheffield, but perhaps not always from there:

The Large Cluster 30

It looks like one of mom’s unknown ancestors had a lot of descendants.

And the Answer Is…

It seems like I’ve increased my knowledge of the unknown (poor pun intended). I still have a shortage on the Lentz side. I’m not sure if there were just not many offspring or what happened. I have at least one early common ancestor at Ancestry, but that match is not in a cluster. Another question would be to identify Cluster 10 at 30 cM. I feel like I have a better idea of the weaving of DNA and families between Gangnus and Schwechheimer in my mother’s ancestry.

Summary and Conclusions

  • The combination of the Shared Clustering program and MS Access help to make a fairly quick analysis of AncestryDNA shared matches
  • My mom’s genealogy is a bit tough. I know she has some more Latvian matches out there but tracing their trees back is difficult in the period when Latvia’s records were in Russian.
  • I don’t have an explanation why my mother’s common ancestors of Lentz and Baker in Philadelphia were not part of clusters.





Leave a Reply

Your email address will not be published. Required fields are marked *