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  • Match at 67 but not 111

    Hi guys,

    I have a member of my project that matches two other members at 67 markers (GD 7), but not at 111 markers. Does this just indicate that the match is so long ago that it is not genealogically relevant or are they not not related at all?

    Thanks,
    Dawn

  • #2
    Has their 67 marker match also tested to 111 markers? If not, then FTDNA can't compare your project members to this 67 marker match at the higher level. The match page will tell you how many markers each match has tested.

    If the 67 marker match has tested 111 markers and isn't on your project members' match list, that indicates the match is not close. Already, with a GD of 7 at 67 markers, the match barely made the threshold to be declared a match. I regard a 60/67 match as probably representing a common ancestor several hundreds years ago, barely in a genealogical time frame. So, it would not be surprising if the match falls away at the higher level.

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    • #3
      One of the two matches did test 111. The other only 67.

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      • #4
        Originally posted by Dawn Ellis View Post
        One of the two matches did test 111. The other only 67.
        it doesn't sound like they are actually related unless they have an unusual amount of mutations. Do these men share the same surname?

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        • #5
          No, different surname.

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          • #6
            If they match at 67 markers, then it's highly unlikely that they match by accident.

            The 111 marker test is sometimes (not always) helpful when you're trying to pin down when the most recent common ancestor lived, or else find the nonsurname match closest to a given person's Y DNA. In the latter case I've seen it yield mostly confusion and little help.

            I've found the test most useful when trying to determine if people match within a 300 to 500 year time frame.

            Failing to match at 111 markers does NOT mean it isn't a match. I've seen people with the same surname and solid paper trails match at 67 markers and not at 111 markers. This test is superfluously restrictive for most peoples' purposes.

            I'm finding it somewhat useful when trying to determine which matches among a medieval group of families, match in the past four or five hundred years. There are holes in teh ability of the existing marker choices to determine TMRCA at that distance, as the fastest changing markers dance in circles at that point and noone seems to konw what to make of them. And predictably only a couple of people have the will and the means to do the Big Y - and then there's learning to extract and identify the relevant SNPs.

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            • #7
              67-MARKER

              I have a 67-marker Y match, with a genetic distance of 1, with a fellow of different surname. In your opinion, roughly when do we share a TMRCA?

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              • #8
                67 markers (GD 7) is very distant and not normally from a common ancestor in the past 500 years. The common ancestor can be from more than 1,500 years ago. John Cleary has an excellent video that presents this with both Y67 test results and BigY test results. The video is at https://youtu.be/pxexkvfus6w

                A 67-marker Y match, with a genetic distance of 1, is very close and the matching would likely still be close at Y111 and with BigY testing but further testing is needed to determine the relatedness of the match.

                A former haplogroup admin has a thread on Anthrogenica about his surname Y111 matches also getting BigY testing to determine the relationships between them.

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                • #9
                  Originally posted by Dawn Ellis View Post
                  No, different surname.
                  If it's a different surname, then a gd at 67 does not mean they match. Lots of false positives with different surnames. FTDNA's gd guidelines re matches only apply to men with the same surname.

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                  • #10
                    Originally posted by TwiddlingThumbs View Post
                    If it's a different surname, then a gd at 67 does not mean they match. Lots of false positives with different surnames. FTDNA's gd guidelines re matches only apply to men with the same surname.
                    Per the following ISOGG article on convergence, a low gd number with someone of a different surname may not indicate any relationship. The lower gd may due to convergence, ie, two unrelated lines having STR results that converged due to a series of mutations that closed the STR marker gap between the two lines. The likelihood that a low gd may be due to convergence depends on a lot on your haplotype. According to the article, for 5-10% of surname groups, up to 90% of their matches might be false positives. If you have a close gd with someone of a different surname, it is worth a look, but may not indicate any relationship. https://isogg.org/wiki/Convergence
                    Last edited by TwiddlingThumbs; 21st July 2017, 08:51 PM.

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                    • #11
                      Originally posted by TwiddlingThumbs View Post
                      If it's a different surname, then a gd at 67 does not mean they match. Lots of false positives with different surnames. FTDNA's gd guidelines re matches only apply to men with the same surname.
                      There are too many NPEs to be able to state that a 67 marker match with a person that has a different surname isn't a match from a genealogical timeframe. The false positives can only be confidently be weeded out by Y111 and/or BigY testing or a similar NGS or WGS test.

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                      • #12
                        Originally posted by TwiddlingThumbs View Post
                        Per the following ISOGG article on convergence, a low gd number with someone of a different surname may not indicate any relationship. The lower gd may due to convergence, ie, two unrelated lines having STR results that converged due to a series of mutations that closed the STR marker gap between the two lines. The likelihood that a low gd may be due to convergence depends on a lot on your haplotype. According to the article, for 5-10% of surname groups, up to 90% of their matches might be false positives. If you have a close gd with someone of a different surname, it is worth a look, but may not indicate any relationship. https://isogg.org/wiki/Convergence
                        This is from your convergence link "It is less likely to occur at 67 markers, though a case has been reported of two 67-marker haplotypes with a genetic distance of 6, which were found to be in different R1b subclades"

                        What they don't say in that sentence, but should, is that a match with a GD of 6 or 7 has a very high probability of not having a common ancestor in the past 500 years which generally most people can't even get past that in their genealogy. They also fail to mention that some 67 marker matches no longer match once the person and the match upgrade to Y111 and that this is due to not having a common ancestor in the past 500 years. Beyond 500-1,000 years then STRs are less reliable than NGS testing estimate how long ago the common ancestor lived.
                        Last edited by Armando; 22nd July 2017, 09:22 AM.

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                        • #13
                          In other words....

                          In simplest terms, if two 67 matches, regardless of surname, each expand their results to 111, they should not diverge from matching if they share a common ancestor within historical genealogical terms. If they continue to show as matches, then it should be investigated as possibly findable with paper genealogy. The genetic distances are guesses, but having 67 matches with the same surname should not mismatch at 111, the mutations are "more recent" but the haplo is not affected. With different surnames, a close match bears further research, but enough mutations to show 6 to 7 gens is probably not worth your time unless there is supplementary evidence to create suspicions.

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                          • #14
                            Comparing the snps

                            So with this group, two of the men have done snp testing. One is R-BY11542, the other is R-S1688. The men have different surnames. I am looking at both of their snp pages. As far as I can tell S1688 is upline from By11542, but it is really hard to follow on the chart, having to scroll. Is there a resource for comparing snps making it easier?

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                            • #15
                              I have never seen one

                              The trees for SNPs along the Y line do not match across services: ISOGG, FTDNA, Yfull have trees, but all such trees are somewhat experimental. I have never received or seen any explanation on FTDNA that breaks down YBP or why my own terminal SNP has been "refined" twice.
                              Occasionally I have Googled a SNP term and found something, but never for my most recent terminal at FTDNA. YFull gives an entirely different SNP name, but at least shows YBP as interpreted by YFull.
                              The answer to your question as far as FTDNA is: you have to contact a haplo admin and be at their mercy, because obviously some of the terminology is proprietary. The SNP tools at FTDNA are not really there except as (as you say) a difficult tree that says "you are here because we say so."

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