Wednesday, November 28, 2018

Cheryl - A GEDmatch Case Study - Part Two

Cheryl matches my families
A few days ago, I wrote about my neighbor Eric whose wife Cheryl has a promising match on GEDmatch with a Skalat Pikholz descendant named Gene. Aside from Gene, Cheryl has a number of other matches with my families.

There are five segments of interest, none very close, but together they may be useful, both for Cheryl herself and as examples of how to use GEDmatch.

Eric was here for a little over an hour, so after we looked at Gene, we went straight to the old reliable one-to-many search which looks at Cheryl's top 2000 matches. I was looking for segments of ten or more centiMorgans where Cheryl has multiple matches in my families. Segments smaller than ten cM may be real, but are certainly too far away to be useful for families such as ours where we have few surnames or records before 1800. And I use multiple matches because I want some evidence that the match is from "our side" and not from the other side of some second, third or fourth cousin.

The five segments of interest
On chromosome 1, Cheryl has about 11 cM with Aunt Betty and Uncle Bob, my father's sister and brother. This is not a large segment and we cannot tell whether this is on my grandfather's side or my grandmother's. And given that, the common ancestor probably lived well before 1800.

On chromosome 5, Cheryl matches my brother, one of my sisters and me on a segment of 10.7 cM. No cousins on either side, so this match could come from anywhere. And it is not large.

On chromosome 9, Cheryl matches my brother, three of my sisters, me and my second cousin Roz, on my father's father's side, with a segment of about 12 cM, plus a nearly-adjacent segment of about 5.6 cM. We all match each other, so we have triangulation. So this segment comes from either my grandfather's Pikholz father or his Kwoczka/Pollak mother, all from the Tarnopol area of east Galicia.

On chromosome 11, Cheryl has a segment of about 15 cM with two of my second cousins on my mother's side. One is Beth, whose grandfather is my grandmother's brother and one is Liya whose grandmother is my grandmother's sister. They match each other, so we have triangulation. My grandmother's descendants do not appear here, nor do Beth and Liya's two first cousins. Is there something here? Maybe. But we have only one surname in my grandmother's family - Rosenbloom from Borisov in Belarus.

Finally, on the X, Cheryl has 20.5 cM with Aunt Betty and 14.9 cM on the same segment with my cousin Roz. They triangulate, so this is a real match. Aunt Betty could not have gotten the X from her father's father and Roz would not be expected to match Aunt Betty's mother, so the match must be from the Kwoczka/Pollak side. We cannot know if it is from the same common ancestor as the segment on chromosome 9, but the possibility is intriguing.

Digging deeper with a better way
At this point, my discussion of last week on the GEDmatch Tier1 one-to-one kicks in. I told Eric that after he signs up for Tier1, he should see if any of Cheryl's matches beyond the initial 2000 can tell us more about these five segments.

But there is a better way. GEDmatch has a tool called "Multiple Kit Analysis." It is marked as NEW, but it has been around for quite awhile. And it is not a Tier1 tool, so it is freely available.

In the Multiple Kit Analysis there are two tabs. Choose the one on the right: "Manual Kit Selection/Entry." If I enter Cheryl's GEDmatch kit in the first box ("Kit 1"), I can compare her to all the kits I enter in the subsequent boxes, whether or not they are in Cheryl's first 2000 matches. For instance, if I enter all the kits from my mother's side, I can see if anyone besides Beth and Liya match Cheryl on the segment on chromosome 11. But entering all those kits by hand is tedious and prone to error. Here I have a short cut that Eric cannot use without knowing the GEDmatch numbers for all my relevant kits.

I use a free program called ShortKeys which I have set up to fill out this form for each of my families. When I did that for my Borisov family (the ShortKey code includes many Borisov residents who are not specifically related to me), I got one more second cousin on the segment with Beth and Liya - Liya's first cousin Lydia. This strengthens this segment as a useful connection between Cheryl and my grandmother's family beyond what we had on the basic one-to-many. Eric could have done this using the Tier1 one-to-many but I find this easier for matches with my families.
Cheryl matches Beth, Lydia and Liya together
That same search gave me another bit of information regarding my mother's side. On chromosome 5, we see the three 10.7 cM matches that I mentioned above - my brother, one sister and me. But we also have 12 cM with my first cousin Mike (line 5), on my mother's side. He triangulates with us here, so this is real.

There are no second cousins on the segment so we don't know which of my mother's sides is represented here.

Uncle Bob, Aunt Betty and Pinchas
line up together on chromosome 1
I also did the Multiple Kit Analysis for the other three segments - the ones that show matches between Cheryl and my father's side. On chromosome 1, where Cheryl's one-to-many showed a match with Aunt Betty and Uncle Bob, the Multiple Kit Analysis gave us one more name: my third cousin Pinchas. Pinchas' great-grandfather is the brother of my great-grandmother Jutte Leah Kwoczka, whose mother is a Pollak.

This match triangulates so it clearly comes from the Kwoczka/Pollak side - not Pikholz and not my grandmother's Hungarian/Slovakian families.

Chromosome 9 showed us nothing new, so we have only the original matches with my second cousin Roz. Maybe Pikholz, maybe Kwoczka/Pollak.
Five of my parents' children and our second cousin Roz (on line 6). Not large but definitely my father's father's side.

Chromosome 23, the X, gave us two new matches - Rhoda and Terry.
The two large yellow matches (20.5 cM) are Aunt Betty and Roz' first cousin Rhoda. The first green match is my second cousin Terry, with 15.2 cM. The second green match is Roz, with 14.9 cM. They all triangulate. This is clearly a Kwoczka/Pollak match.

This X match and the Kwoczka/Pollak match on chromosome 1 may or may not be from the same ancestral source.

The ball is now in Eric's court. He can do Matching Segments and write to others who share these matches. But perhaps more important, he can get some of Cheryl's first and second cousins to test, so he can see which of Cheryl's ancestors provided these segments.

When he comes back to me, I'll report it here.

Housekeeping notes
I shall be speaking, in Hebrew, for the Rishon LeZion branch of the Israel Genealogical Society on Monday, 14 January at 7 PM at the Rishon LeZion Museum, 2 Ahad Haam Street. This is not a DNA presentation, though there are a few DNA references. The topic is

מֵעֵבֶר לְסָפֵק סָבִיר
מה שיודעים, לעומת מה שאפשר להוכיח
What We Know vs. What We Can Prove

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