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CMH Haplotype vs. Haplogroup

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  • CMH Haplotype vs. Haplogroup

    OK, I have posted on a similar topic before, and I apologize to those who are not interested in this topic for the lengthy post. But there is something about my STR match data that strikes me as peculiar, and I am very interested to see if any of the genealogical and statistical experts on this site can offer me something I have not thought of.

    About half the people I match both on the Haplogroup page and the REO page claim to be Ashkenazi Cohanim. Half are Ashkenazim who do not. I do NOT have the CMH--I am three steps off, one STR at one locus and 2 at another, and I am a J2 by SNP testing (CMH is supposed to be in J*). Looking at the way the statistics work, the fact that I have these matches at the 25 and 37 marker level appears to indicate recent common ancestry (last few hundred years), but I am not a Cohen. That is a puzzle, but let's assume that I just have a similar haplotype, the statistics are wrong, I don't really have a recent common ancestor with those people, or that non-paternal events were involved in the ancestry of those J2 "Cohens." I will leave that issue for now.

    Here is the peculiar thing: Of the people whom I match on the basis of similar STR haplotypes, and who claim to be Cohanim, exactly half based on SNP testing (haplogroup page) are J, and half are J2. That's 4 matches in each category, or 6 in each category if I also include people claiming Levite status.

    Let's now assume that there are two lineages of "Cohanim" (as is the case with Ashkenazi Levites, some of whom are R1a1). This is the "Second Temple" hypothesis, that some men "bought" the status at that time. The problem is that while J and J2 are common, and it is not a surprise that two lineages claiming Cohen status would belong to these two groups, it is very surprising that the SAME HAPLOTYPE (matching mine) would be found in people claiming the status even though they are from DIFFERENT SNP HAPLOGROUPS. This could be coincidence, since Js and J2s seem to share a lot of STR patterns, but it is still very surprising that the frequency of claims of Cohen status correlates with STR haplotype independent of haplogroup! The N is small, and the other possible explanation is that this is a statistical fluke; that there are so many people claiming Cohen status that they have flooded the database and that half of *all* SNP-tested J and J2 Ashkenazim in the FTDNA and Hammer databases claim this status.

    It is also interesting to see a few Levites showing up in this data, also equally distributed between J and J2. That becomes statistically very hard to explain when taken with the Cohen data, unless (1) as postulated above, ALL J and J2 Ashkenazim are equally likely to claim the status regardless of haplotype; or (2) some people who think they are Levites are confused about their status. Though the overall problem of haplogroup vs. haplotype is still there, the second explanation at least eliminates having to postulate the same problem for two different sets of people.

    Any thoughts on this would be appreciated!

    Jeff Schweitzer