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STR V SNP V TIP report

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  • STR V SNP V TIP report

    This is how I understand it, but I would like confirmation or correction.

    The tip report percentages become worthless if either:
    1) If you and other match both tested at a higher number of strs and you are no longer a match at the higher level test
    2) The person is in a different haplogroup.

    With respect to one, if I took the 111 test and I match some person A who took the 67 test. The fact that we match at 37 doesn't mean much if we don't match at 67. The tip report percentages at the 37 level are not valid in light of the other strs tested.

    With respect to the second case say I test with person B and they are haplogroup rm222. I am listed/predicted at rm269 after taking a the 111 str test. So even though we show as a match at a str 67 level and the Tip reports gives us some chance of being related in the last 20 or so generations we know that is impossible since we know the rm 222 haplogroup was created about 16 centuries ago. So clearly the tip report is not valid in light of the fact that we are different haplogroups.

    Like I said if I am wrong on any of this let me know.
    Thanks in advance.

  • #2
    I believe R-M222 is down stream of R-M269 which is a common "Predicted" Haplogroup. R-M222 is a SNP tested Haplogroup. Just the fact they are different doesn't tell you much. To compare Haplogroups you need to have the same level of SNP testing.

    The TiP report is based of average mutation rates? Do both people have the average mutation rate? Probably not! I
    The percentages given are based on "probability". Remember that if there is a 70% probability something is true there is a 30% probability it is fales. Point being - that the TiP reports as a VERY rough estimate.


    • #3
      According to the public haplotree R-M222 is downstream of R-M269, so the other match could be M222 as well, they just haven't tested at the higher level. And a quick look at YFull for M222 gives an MRCA prediction of 2300 YBP, which gives enough distance in time/generations that both could be R-M222 and not meet the matching criteria at 67 STR markers.

      Also it should be noted, there is a difference between SNP prediction with STRs, and actual SNP tests. SNP results take precedence over anything STR. When you have both, the STR results get used to work out relationships within the SNP result set.

      Edit: Also with TiP reports, you can run them up to the highest level mutually tested, not just the levels you happen to match at. So unless you're doing Apples to Apples comparisons I don't know why you'd rely on a 37STR TiP when a 67 or 111 STR version is available.
      Last edited by bartarl260; 5 February 2019, 10:53 AM.