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Gedmatch and Y-DNA

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  • #16
    Originally posted by Germanica View Post
    My understanding is that Y SNPs aren't useful for recent genealogy though - it's the STRs which can be.
    Y-SNPs can be useful for recent genealogy. Some of the SNP tests you mention look at ancient SNPS which of course won't help with genealogy. However if people were close matches in a new generation sequencing test like Big Y, those SNPs can be used to connect the dots with other people's results. Think of it like a tree. SNPs are the branches and STRs can be the leaves.


    • #17
      Originally posted by mwwalsh View Post
      As far as Y STR testing used for full genetic genealogy there is no other effective option than FTDNA.

      "635,395 Y-DNA records in the database"

      "9,749 surname projects"

      Please read the "Why Y DNA testing?" answer on the R1b project FAQ page. To be useful for matching and finding potentially related people everyone has to get tested at them STR locations, with the same methods and with access to contact matches, etc. The size and quality of the matching database is critical.

      "The comparison method for tree building is simple, just compare validated mutations across potential relatives. If you have two brothers that have the same mutation unique to them then you can legitimately assume their most recent common ancestor, their father, had it. If you check a male cousin and he has the same mutation you can back up a step and know the grandfather had it. However, you need apples to apples comparisons of test results. It is of little value to do tests that few others are doing. Think of this as a team sport. You have to get others potentially related to take the same tests as you do or find them in the matching database. This is why the size of the matching database and recruiting efforts are so important."
      I didn't really say anything to the contrary. All I'm saying is there are other companies that do Y testing, and we don't know what the size of most of their databases are. Probably, they aren't as big as FTDNA's but who really knows.


      • #18
        Originally posted by Oldcrone View Post
        Seems obvious to me. We have a match who tested with 23 and Me. We know this person matches us on autosomal but we have no way to see if their YDNA is a match for our newphew's Y. Unfortunately, Ysearch seems to have not been maintained and doesn't work very well.
        but 23 doesn't test any STR

        there is really no other data to compare to other than FTDNA so no point in GEDMATCH replicating FTDNA STR matching (only with a vastly smaller database since most people don't upload to GEDMATCH)


        • #19
          take big-y to