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SNP "Add" determined how?

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  • SNP "Add" determined how?

    I've done the Y111, which I followed with the recommended I2-M223 SNP pack, which came back I-Y3713. Now I see 19 downstream (blue) SNP (possibilities?), yet only one has the "Add" next to it. What is the logic for only doing 1 downstream test? i.e. how is it determined that one and only that one should be added? I only have one match at Y67 and Y111, and both are the same person. Will this added SNP help or just more information for the future?

    And, one more thing, with things narrowed down like they are, is there any reason to take a BigY700 test? Would it show anymore than additional branches I DO NOT match, or are there potential matches not yet revealed with the tests done so far?
    Last edited by BenInTx; 12 March 2019, 02:32 PM.

  • #2
    Did you check whether the tests for the other 18 SNPs can be bought? You can check that on the page where the tests for the individual SNPs are being sold.

    BigY is a more comprehensive test than SNP packs, however, when having many family members tested, BigY is not required for everyone. Too complicate the picture..., there are situations where a test for an individual SNP might be required in addition to BigY.

    Mr. W.


    • #3
      Purchasable SNPs are added primarily at the discretion/request of Group Project administrators. FTDNA will sometimes make other tests purchasable at their own discretion as well, without group admins getting involved.

      That said, the SNP testing paradigm changed with the introduction of the BigY, The single SNP tests are basically a legacy and specialist product that remains available because it remains an effective specialized tool that is very useful for certain types of projects.

      In particular, "advanced" Surname studies would be a good example(where you already have "several" BigY tests spanning a significant portion of the haplotree). Instead of paying out for yet another BigY, they can STR test somebody, then spend $40 on a single SNP test or $100/$120 for a SNP Pack and test a range of SNPs, rather than shelling out another $200 beyond that for BigY. Basically testing 3+ people for the same money that would BigY test 2 people who won't really bring much new to the table(unless they happen to have a new mutation, which is possible, but...)


      • #4
        Originally posted by bartarl260 View Post
        Purchasable SNPs are added primarily at the discretion/request of Group Project administrators. FTDNA will sometimes make other tests purchasable at their own discretion as well, without group admins getting involved.
        So, I'm a bit confused. The page I'm talking about isn't in the Thompson project section. From the Main FTDNA screen I select MyDNA>Y-DNA>Haplotree & SNPs, which brings me to a big table. B293 is Blue and is standalone (no subgroups), Y6028 is blue except for 2 subbranches that are red and 17 (branches and subbranches) are blue. The only one that shows Add is Y6028-BY49562-BY28901. Are you saying this one "Add" is from the Thompson Project admin? If I select "more" next o BY28901 I see

        I'm trying to figure out why the "Add" for that one subbranch, as opposed to all the others that are blue. "Add" is not an option for the other blue entries.


        • #5
          Once a SNP is added to the list of tests that FTDNA will test, it becomes available to everyone. It also could have been a haplogroup project that requested the SNP at one point in time, although I think most such projects only request single SNP tests very sparingly now, BigY is much more useful and not as likely to have issues from STR convergence.

          Also red SNPs usually are single SNPs you have tested and came back negative on. I am guessing you purchased a SNP pack at some point? (As BigY results only grey things out at most when it comes to non-positive results)

          Edit: It also is possible that particular SNP was one of the first ones to demonstrate further/deeper branching in testing, so FTDNA itself made the SNP testable as they anticipated it was "a significant branch" absent a project admin asking for it. As mentioned already, there are a few ways single SNP tests come into being.

          Your ability to order a SNP test which has been made available is only negatively impacted in the screen you mention if you either test negative for an "upstream" marker, or test positive for a marker on a different line(and thus unlikely to belong to that other line). Which isn't to say you can't order the SNP test anyway if you really wanted to, you just need to find the right ordering screen...

          The Blue SNPs you see on that ordering screen are "downstream" from where your testing currently places you. The "add" button only being present on one test, no tests, or all of them is contingent on "somebody" having requested that FTDNA create a single SNP test panel for that marker.
          Last edited by bartarl260; 14 March 2019, 10:56 AM.