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Am I expecting too much?

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  • Am I expecting too much?

    I wanted to get the opinion of others on these results. Below I've linked to a page that has a table with 25-marker results on 5 Middleton's.

    I got started with FTDNA in the late 1990's or early 2000. A few of us who knew that we were from a Middleton line that can trace back to the same area in SC, sent in for our tests. All five matched 12/12. Of those tested, 2 of us know our line went from SC to AL, and we ultimately matched 36/37. The other 3 went a little earlier from SC to MS Territory. They matched 35/37 (x2) and 31/37.

    With the 12-marker results I was really excited as I assumed the results proved our speculation that 5 Middleton's who migrated from Marion, SC to Monroe County, AL (~1822), were in fact brothers. But, became disillusioned with the subsequent results. For me the assumed MRCA is only 5 generations away; thus, I would have expected the results to be closer.

    Am I making too much of this, or expecting too much? Any feedback appreciate!

    http://jwm1125.bravehost.com/final/midd-dna.htm

  • #2
    As you know, mutations are random events. The TMRCA is just an average, and the standard errors associated with the estimates are large. So it is certainly possible that your conjecture is right, one cannot say. the 31/37 seems really far off, but the 35/37 are well within the range of possibilities.

    As usual, a 60+ markers test will be a little more precise (though, even there, you won't be able to know for sure).

    cacio

    Comment


    • #3
      First off: Congratulations. I'm going on the best part of a decade of testing without a single significant match. You were very fortunate to get multiple matches w/ good reasonably good pedigrees.

      But the short answer to your question is, "Yes, you are expecting too much.". Y chromo DNA is an excellent tool for determining paternal relationships w/i the last 300 to 400 years, but you must remember that even within that timeframe there is random variation in the rate of mutation for each line. There's no getting around that central fact and its implication that you just can't use GD as a super-reliable TMRCA calculator.

      I have no doubt that you all are fairly-closely related, but the truth of the matter is that the amount of random variation in occurrence of mutation precludes placing too much confidence in GD as a genetic clock. The mutation rates used by the calculator formulae are good, but they represent only "typical" rates for the population at large-individual experiences will always vary to some degree. Unavoidable.

      I could tell you some really freaky stories that prove the point, but don't want to take away from your success. You should be very pleased that you've confirmed that you all are paternally related, even if DNA alone can't tell you precisely how.

      There will, fortunately or unfortunately, always be a need for good, vigorous paper trails.

      Originally posted by jwmiddleton View Post
      I wanted to get the opinion of others on these results. Below I've linked to a page that has a table with 25-marker results on 5 Middleton's.

      I got started with FTDNA in the late 1990's or early 2000. A few of us who knew that we were from a Middleton line that can trace back to the same area in SC, sent in for our tests. All five matched 12/12. Of those tested, 2 of us know our line went from SC to AL, and we ultimately matched 36/37. The other 3 went a little earlier from SC to MS Territory. They matched 35/37 (x2) and 31/37.

      With the 12-marker results I was really excited as I assumed the results proved our speculation that 5 Middleton's who migrated from Marion, SC to Monroe County, AL (~1822), were in fact brothers. But, became disillusioned with the subsequent results. For me the assumed MRCA is only 5 generations away; thus, I would have expected the results to be closer.

      Am I making too much of this, or expecting too much? Any feedback appreciate!

      http://jwm1125.bravehost.com/final/midd-dna.htm

      Comment


      • #4
        No! I don't think you are expecting too much. I think you should try to get everyone to upgrade to at least 37 markers.

        The only kit that I would wonder about at this point is #29.

        Comment


        • #5
          Originally posted by jwmiddleton View Post
          I wanted to get the opinion of others on these results. Below I've linked to a page that has a table with 25-marker results on 5 Middleton's.

          I got started with FTDNA in the late 1990's or early 2000. A few of us who knew that we were from a Middleton line that can trace back to the same area in SC, sent in for our tests. All five matched 12/12. Of those tested, 2 of us know our line went from SC to AL, and we ultimately matched 36/37. The other 3 went a little earlier from SC to MS Territory. They matched 35/37 (x2) and 31/37.

          With the 12-marker results I was really excited as I assumed the results proved our speculation that 5 Middleton's who migrated from Marion, SC to Monroe County, AL (~1822), were in fact brothers. But, became disillusioned with the subsequent results. For me the assumed MRCA is only 5 generations away; thus, I would have expected the results to be closer.

          Am I making too much of this, or expecting too much? Any feedback appreciate!

          http://jwm1125.bravehost.com/final/midd-dna.htm
          Familes vary dramatically in the rate of Y mutation (a debatable point). I have individuals in my Shetland Islands Project who cannot possibly share an ancestor in common for 400 years, same surname, one from Scottish Mainland one from Shetland, but match 37/37. My father and I match 32/37 with his second cousin. All tested with my surname and a paper trail to the same ancestor born 1618 (8th cousins) match my Dad and I between 34 and 31/37. However, every one of us has the same very off modal marker values with no one but those of our surname with 31 of 37 markers. So in other words, 31 / 37 is not necessarily cause for concern. I would look at the slow moving markers unique to this Middleton lineage.

          DKF.

          Comment


          • #6
            Well, since you brought up the point, I will share my tired old "This Shouldn't Be Able to Happen" story. It is the freakiest thing I'd ever heard of.

            A guy with a fairly rare Yorkshire surname (let's call him "American A") had a bunch of suspected relatives on both sides of the pond test 67 markers--with great results, basically confirming pedigrees that went back to the late 1500's. But here's the twist: "American A" was GD of 5 vs. "American B", who connected in the mid-1700's, but GD of ZERO [0] vs."Mr. Brit"--who could not possibly have hared a common ancestor after about 1600.

            Now that type of thing makes my head fairly spin. I guess there are any number of possibilities involving coincidental back-mutations or mutations between the lines of "American A" and "Mr. Brit", but the inescapable impression I'm left with is that at 67 markers, given weighted average "typical" mutation rates of between 0.2% and 0.4% per marker for that range of 67 markers, the odds of something like this happening is on the order of winning the big Lotto.

            So I guess there's no escaping randomness, even within lineages.


            Originally posted by DKF View Post
            Familes vary dramatically in the rate of Y mutation (a debatable point). I have individuals in my Shetland Islands Project who cannot possibly share an ancestor in common for 400 years, same surname, one from Scottish Mainland one from Shetland, but match 37/37. My father and I match 32/37 with his second cousin. All tested with my surname and a paper trail to the same ancestor born 1618 (8th cousins) match my Dad and I between 34 and 31/37. However, every one of us has the same very off modal marker values with no one but those of our surname with 31 of 37 markers. So in other words, 31 / 37 is not necessarily cause for concern. I would look at the slow moving markers unique to this Middleton lineage.

            DKF.

            Comment


            • #7
              Thanks for all the input!

              I appreciate all of you taking your time to respond. This whole process can be so frustrating.

              Now if I can just get Kate Middleton's dad to submit his DNA....

              Comment

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