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thetick
01-27-2013, 08:08 PM
I've asked this before but now with some more data I'm still really up in the air if I have a distant Jewish ancestor or just happen to have enough common German/East European ancestry with Jewish groups. I'm thinking in the 1/64th range, but it could be much farther back due to inbreeding and/or 23andme's high Jewish customer count.

Here is my evidence:

1) Currently 742 RF matches with quite a few showing only Jewish ancestry -- difficult to quantity see AF data
2) With AF's Declared Ashkenazi Jewish 5cM+: 1GP - 1.1%-2.1% --- 4 GP - 0.5%-0.8%
But the raw numbers from AF cvs show:

7 matches in 7cMs
5 matches in 8cMs
4 matches in 9cMs
4 matches in 10cMs
3 matches in 11cMs

-- note all three 11cM matches are chromosome #7 from 55-75M .. Is this a known cold spot with ancient DNA?

3) By comparing AC to AF I can a good idea which Jewish matches with less than 4 Jewish GPs are on the Jewish side. See

AJL
01-28-2013, 04:03 AM
I'm not sure if this is a cold spot, but the X block in tandem with the autosomes does make this a little more compelling, though it looks as if the trailing-off suggests the true block size may be shorter than 11 cM, and your match is extended through coincidence. It's hard to say which way the influence is going, but it was more common over the past 500 years for Jews to become various sorts of Christians than the reverse. There is some possibility that Anabaptism attracted Jews because of its rejection of Catholicism, with which Jews had a fraught relationship in parts of Western Europe because of the Inquisition. However, I'd guess the connection is more likely to come from Poland. Many Ashkenazim show up to 0.5-1.0% Eastern European in Ancestry Composition, so again, it's hard to conclude which direction the genes are flowing.

thetick
01-28-2013, 05:53 AM
Thanks for the good comments.

I also think the X match is the key. That's mom's side only and is the all most all Polish/Rusyn side. My dad's side is documented back to 5th great grandparents, all PA Dutch (German/Swiss) with one distant branch Scottish. My mother's side is a complete mystery past great grandparents, due to limited document access and inability to read written Old Slavic.

I can also look at the AC results and noticed the Jewish blocks NEVER overlap the Eastern European blocks (which is mom's side). Mom's side definitely has a small amount of German and British/Scottish which can be confusing determining which side.

Finally.. certainly it is possible there are a few very distant Jewish matches (with possibly some dna cold spots) on both my parents sides and collectively makes my results show I have more recent Jewish ancestry.

AJL
01-28-2013, 04:47 PM
You're most welcome.

Re your mother's Scottish connection, there was a mass migration of Catholic Scots to Poland during the Scottish Reformation. My mother has a few Polish DNA matches, which might tie into her German side (and I can't be sure which way the genes are going), or to her Scottish (in which case I would suspect the direction is Scotland > Poland).

As to the Jewish connection, if your Rusyn and Polish ancestors were living in a small area, they might have been fairly endogamous, and the block could go back quite a way, with the same genes introduced early into the Polish/Ukrainian Ashkenazi gene pool circulating in parallel, with no way of predicting the source. There a similar phenomenon, where entirely Ashkenazi people are getting matches to Iberoamericans with sometimes quite remote crypto-Sephardi ancestry, but often not with actual Sephardim. In that case too, it's because restrictions in the gene pool in both populations limit the number of possible ancestors i.e. increase the odds of receiving an old DNA segment.

The best way to guess where such blocks are from is to amass a number of these matches and see whether one group predominates over the other, and also, in which group the blocks are largest.

thetick
01-29-2013, 03:34 AM
Excellent theories which I now think you are probably right on on both cases.

For the Scottish Polish connection there is plenty of history between the two. See http://voices.yahoo.com/scottish-polish-connections-history-relations-between-2536000.html. Also on related note my current terminal mtDNA is all Polish and Scottish, but with only a handful of data points.

For the Jewish connection, my Rusyn and Polish ancestors were peasants living in a small isolated area near the Carpathian mountains, so definitely endogamous. So restrictions in the gene pool in both populations limit the number of possible ancestors i.e. increase the odds of receiving an old DNA segment.

That Rusyn and Polish side was very adamant about being Catholic or Orthodox. My mother married a dreaded Protestant and converted so we were not warmly welcomed with that Rusyn and Polish side. I originally suspected from DNA results there was a Jewish ancestor not too far back that the family was hiding.

dp
09-24-2014, 05:25 PM
[withdrawn due to thread under 23andme]