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Y Chromosome matches

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  • Y Chromosome matches

    I would appreciate a few opinions on my Y Chromosome matches

    I took the 12 marker Y Chromosome test a couple of years ago mainly to get a predicted haplogroup. I found I had made an exact 12-marker match with two other members of my surname project (DAVIS). As Davis is a very common surname and I have 300+ other 12 marker matches with people with other surnames I did not read too much into this.

    I ordered the family finder test earlier this year and that re-ignited my interest in the earlier Y Chromosome results and I decided to upgrade. At 25 markers I had a single exact match. This was to someone with the surname SMETTERS. At this point I wondered if this match was from before the genealogical paper timeframe or an indicator of a possible false paternity event. I also had 14 genetic distance of 1 matches at 25 markers and 10 of these with individuals with surname variants of SMETTERS. With so many SMETTERS matches I was then concerned that the false paternity event may have been in my direct line.

    However the exact SMETTERS match at 25 and the 11 other genetic distance 1 SMETTERS at 25 have all tested at 37 or higher markers as well and when I compare them to my 37 marker results none of them match me at all at 37 markers even as far out as a genetic distance of 4.

    So based on the 37 marker results I am leaning towards it being more probable that my relationship to the SMETTERS is from before the period when surnames formed and less likely to indicate a false paternity event in my Davis line.

    Does this conclusion sound reasonable in terms of its probability?

  • #2
    Yes. And if your type is R1b, this situation would be very common with a number of surnames.



    • #3
      Thanks, and yes I am R1b.


      • #4
        Conversely, I have a predicted haplogroup of R1b1a2 like so any others, but have no exact matches; I have a near match with a distance of 1/37 who shares my surname, two more matches at 2/25, and another eleven at 1/12.

        I'd have expected, being in such a common haplogroup, to have more matches or partial matches. Is this a misconception? Are there any published statistics for variance of STR values per haplogroup?


        • #5
          (To pre-empt the question, I have "I want my matches to be set against the entire database" set in preferences, with checkmarks set for all values under "When displaying matches only show".)


          • #6
            I'd have expected, being in such a common haplogroup, to have more matches or partial matches. Is this a misconception?
            I think there are a number of us belonging to very common haplogroups that have no matches at any marker level. My deep clade L21 , for example, is the same as around 80% of all Irish males. I am a L21 from the Continent however
            and I think there is great deal of variance in markers from say the Irish group (or so I have been told).
            I would suggest after getting your deep clade results join a matching project
            as they can be most helpful.