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  • Zero step mtDNA match

    Hi, I'm very new to the world of DNA testing, so I would be very grateful for some insight on the following dilemna.
    My paternal uncle recently tested and got a zero step match on his mtDNA results. I was contacted by this match (as I am the email contact for my uncle) who was very anxious to establish the relationship, as he was adopted and had drawn a blank until now on his mother's line.
    Both my uncle and I are very anxious to help him, however we could not find a likely candidate on the recent female line. It then struck me that as we had all 3 taken the Family Finder test that we should match on that test - but we didn't, at all. My uncle and I show up as close relatives as you would expect, but the gentleman in question doesn't match either of us.
    I was given to understand that a zero step match on mtDNA indicates a very close relationship, but maybe this was wrong information?
    Thanks for any help

  • #2
    On your last question on whether this is wrong information -- I believe it depends on the haplogoup. In my case I already got 88 zero step matches and the list is growing. None helped in getting any closer to actual genealogical connections.

    G
    Y - R1b1a2 (waiting for Geno 2.0)
    mt - k1a1b1a

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    • #3
      An exact match (0) in FMS means FTDNA feels you are related within the past 16 generations (16 gen x 25y/gen = approx. within last 400 years) with a 90% confidence interval.

      Due to DNA recombination also keep in mind the following as the further back you go the less likely you will share the same DNA of ancestor.

      Family Finder Matching
      Relationship Match Probability
      2nd cousins or closer > 99%
      3rd cousin > 90%
      4th cousin > 50%
      5th cousin > 10%
      6th cousin and more distant Remote - typically less than 2%

      Best I think you can do for him is to share your maternal line pedigree as far back as you can and have him search each of these maternal lines down looking at all the lines (all the sisters of your maternal line, who had daughters) who would of inherited this mtDNA to see if he can trace one to his area of birth. Maybe a momentous task but may turn out to be worth it.

      The other thing you can do is compare each others FF match list and see if you guys share any common matches, this may also suggest a relationship somewhere. Not referring to Triangulation feature as this only works if you two match each other, you would have to share match list and compare.

      Edit - When I share match list, I omit email and ancestral surnames out of courtesy to my matches. If they have a common match they will have this info already.
      Last edited by prairielad; 11 November 2013, 08:30 PM.

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      • #4
        That was a good idea, to use FF. Most mt groups are very old, so a match could also be very old. I am glad you did not get unintentionally get his hopes up. My mt group is considered to be less than 500 years old (very young), but I have yet to connect with any of the other seven in the group.

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        • #5
          Thanks for all the replies, and so fast -as a first time poster, I'm impressed!
          For the record the Haplogroup in question is T2b7A2. I don't know if this is old or new, or how would I check that?
          Comparing FF matches sounds like a really good idea. I can go back to a gg grandmother, born c. 1820, but given the lack of Irish records before then it is unlikely I'll get back any further with a paper trail.
          Thank you too for the suggestion of omitting emails and ancestral surnames when comparing - I am always conscious that we deal in an area where privacy must be respected if people are to have the confidence to share their data.

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          • #6
            At Which Level?

            Originally posted by seawarrior View Post
            My paternal uncle recently tested and got a zero step match on his mtDNA results.
            Without knowing at which level the zero step match occurred it is impossible to even start to answer your question. Is the match a HVR1, HVR1 & HVR2 or FMS?

            This weekend we were told that there was a 50% probability that a zero step match for FMS would be within 5 generations. A 75% probability that a zero step match for FMS would be within 9 generations. And a 90% probability that a zero step match for FMS would be within 165 generations.

            On the other hand the probability for a zero step match for HVR1 only is 50% within 52 generations.

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            • #7
              Thanks Jim. The test taken was FMS, but in view of the statistics I see there is a significant chance that the common ancestor was many, many generations back.

              By the way I did reply to the above replies but it hasn't appeared yet, thanks to all

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              • #8
                0-Step Match

                Recently I received info of a MtDNA 0-step match. We are both C1b11 (Native American). What are the possibilities that we do share a common ancestor. This is what I know so far. My maternal grandmothers can be traced to around 1750 in New Mexico. The Spanish resettled NM around 1690.
                The individual I match with and I are currently comparing families to see where our ancestors might have crossed paths. Based on when the Spanish returned to NM, would it be safe to assume that a common ancestor could be within the last 300-350 years? I am fairly certain that we do not share an ancestor from 1800 forward. Thanks for any insight.

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                • #9
                  No. If you had a Spanish maternal haplotype, you *might* be able to say the connection is likely in the last 350 years. However given that you have an NA haplotype, I don't think you can say much of anything about how long ago the connection was.

                  I would suggest trying to find the connection, but realizing that it may be much further back than you will be able to track.

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                  • #10
                    Not sure if I follow you. As my MtDNA shows a Native American haplogroup, doesn't that mean that my maternal ancestor was Native American sometime in the past? The reason I used 350 years was because the Spanish settled in New Mexico late 1500 to early 1600. Then after the Pueblo revolt, they then resettled in New Mexico in 1690. Sometime during this period a Native American woman could have had a daughter by a Spanish settler, then granddaughters, etc. Then also their were adoptions of Native American children.
                    I understand that my 0-step match do not have a 100% possibility of sharing a common ancestor and even if we did, the paper trail may not be available to prove it. Currently I have traced my maternal ancestors goes back to 1750 and my match can trace theirs back to about 1850. A lot more digging to do.

                    My YDna - G2a3b1a2a1 (United Kingdom)
                    My MtDNA - C1b11

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                    • #11
                      Got to looking at my post above and realized another way this could be played. Native American mother has daughters and their daughters (X number of generations later) have a daughters by Spanish settlers. Then the common ancestor could be well beyond the 350 years I was guessing. Looks like what I thought was obvious was not really the correct answer. Oh well, that's what makes this journey so much fun.

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                      • #12
                        Originally posted by JThom View Post
                        I understand that my 0-step match do not have a 100% possibility of sharing a common ancestor and even if we did, the paper trail may not be available to prove it.
                        Your 0-step match means, you do have a common maternal ancestor and it is indeed significant. I would roughly put within 500 years. You can see the explanation for it in this FAQ.

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                        • #13
                          Originally posted by felix View Post
                          Your 0-step match means, you do have a common maternal ancestor and it is indeed significant. I would roughly put within 500 years. You can see the explanation for it in this FAQ.
                          There are many experienced genetic genealogists, myself included, who think the information in the FAQ you linked to is too optimistic. If their estimate for time to the most recent common maternal ancestor were accurate, we'd see more common ancestors found in the paper trails of 0-step matches.

                          The FAQ states the most recent common ancestor for 0-step mtDNA matches at the 50% probability level is only 5 generations. That's not a long time at all for anyone who's done serious paper trail research. Yet, the number of times I've heard that two people have found the most recent common ancestor for a 0-step match is few and far between.

                          Do you know of a study which actually establishes as proven what FTDNA's FAQ states?
                          Last edited by MMaddi; 7 December 2013, 10:12 AM.

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                          • #14
                            Originally posted by MMaddi View Post
                            There are many experienced genetic genealogists, myself included, who think the information in the FAQ you linked to is too optimistic. If their estimate for time to the most recent common maternal ancestor were accurate, we'd see more common ancestors found in the paper trails of 0-step matches.
                            If more genealogists were able to trace their female lineages back 500 years and were also able to trace that most distant ancestors' female lineage descendants forward to the present generations, we would see more confirmed relationships. Marie Redquist and others tracing the well documented lineages in Canada have demonstrated that full sequence exact matches are meaningful.

                            Originally posted by MMaddi View Post
                            The FAQ states the most recent common ancestor for 0-step mtDNA matches at the 50% probability level is only 5 generations. That's not a long time at all for anyone who's done serious paper trail research. Yet, the number of times I've heard that two people have found the most recent common ancestor for a 0-step match is few and far between.

                            Do you know of a study which actually establishes as proven what FTDNA's FAQ states?
                            I was also deeply skeptical of the dates in that table as they predated my taking over the FAQ. A few months ago I had Bennett Greenspan send an update/review request to both Dr. D. Behar and Dr. B. Walsh. They approved it as you now see it. You can check Google Scholar for their publications if you are expressing doubt as to their competence and credentials.

                            I, of course, would love to see more testing done by genealogists with known 7th through 10th cousins as I favor the findings of the genetic genealogy community when we take on a problem. Without those though, we have to trust PhD touting population geneticists and molecular biologists.

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                            • #15
                              Given differences in the rate at which mutations accumulate in maternal lines, I think it is difficult to develop an average statistic that works for everyone. A better approach is to determine the estimated age of your most refined subclade, and count the extra mutations in your test results that have accumulated since that time.

                              For example, U5a1a1 is estimated by Behar et al. 2012 to be about 6800 years old. There are 36 people who are U5a1a1 with no extra mutations and who all match each exactly. So for these folks, an exact match is not very likely to share a recent common ancestor, as the common ancestor could be at anytime after the age of U5a1a1. There are also people in U5a1a1 with 6 or more extra mutations, so an exact match will be much more recent for these people because they have large numbers of recent mutations in their maternal line.

                              The average rate of mutations in the full mtDNA genome has been estimtated by Soares et al. 2009 to be about 1 mutation in 3600 years. Given the slow mutation rate, the estimates in the FAQ seem optimistic. However, population dynamics also affects the closeness of matches, and it is possible that a population bottleneck would result in people who have no extra mutations sharing a more recent ancestor than the age of the subclade itself. If the table in the FAQ was based on analysis of results of a community with a population bottleneck, the table might not be generally accurate.

                              So I do think more analysis is needed of the table in the FAQ, and perhaps a customer specific estimate could be developed that takes into account subclade age estimates and number of recent, extra mutations.
                              Last edited by GST; 7 December 2013, 04:28 PM. Reason: typo

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