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  • Test results and paper trail? Please help!!

    Hello
    I am hoping that some of you hear can help explain the results of my DNA testing.
    This is the paper trail for my match and I, both with last name Mozley. (My father's DNA was used, of course). We are very confidant in our research as it is the result of years of independent work. Though we have never met, I have no doubt we are related. My question concerns the distance to the most recent common ancestor.

    The paper trail is as follows:
    Edward Mozley (b abt 1735)> Edwin> Samuel G.> Isaiah Irvin> Mozley> Mozley > Mozley> Living Mozley.

    Edward Mozley (b abt 1735)> James H,> Caleb Turner> James Madison> Mozley> Mozley > Mozley> Living Mozley
    Note that both men tested are 7 generations away from the common ancestor.
    Now I am left with trying to reconcile this research with the DNA results.

    Edward Mozley b abt 1735, sold 200acres Bedford Co. VA 1788
    Halotype:
    65905 - R1a1 deep tested; 93067 - R1a (being deep tested now)

    PANEL 1
    DYS# 393 390 19* 391 385a 385b 426 388 439 389-1 392 389-2
    Kit #
    65905 Alleles 13 25 15 11 10 14 12 12 10 12 11 31
    93067 Alleles 13 25 15 11 9 14 12 12 10 12 11 30

    PANEL 2
    DYS# 458 459a 459b 455 454 447 437 448 449 464a** 464b** 464c** 464d**
    Kit #
    65905 Alleles 15 9 10 11 11 24 15 20 33 12 15 15 16
    93067 Alleles 15 9 10 11 11 24 15 20 33 12 15 15 16

    PANEL 3
    DYS# 460 GATA H4 YCA II a YCA II b 456 607 576 570 CDY a CDY b 442 438
    65905 Alleles 11 11 20 23 17 15 18 18 34 36 14 11
    93067 Alleles 11 11 20 23 17 15 18 18 34 37 14 11

    Using the FTDNATIP calculator if we plug in that we could not have shared a common ancestor in the last 6 generations (which we know is true) there is 10.89% chance we share a common ancestor in the last 7 generations, a 22.33% chance in the last 8.
    At 20 generations back we reach 95%.
    Yet our paper trail research says our common ancestor is indeed 8 generations back.
    I am retesting the 3 markers on which we differ.
    We are both expanding our testing to 67 markers.
    I have ordered the deep testing on the halotype group for my kit.
    These are my questions.
    Are these results at odds with my paper trail?
    Is it possible that my family had a mutation and his family had a mutation in the first 12.
    Or that one of us had two mutations. Wouldn't that be rare?
    Can any of you share any info about the markers on which we differ?
    If there is a 22% chance of our MCRA being within the last 8 generations, is it possible that we just happen to lie on the edge of the curve and our common ancestor being within 7 generations is still congruent with the results of the DNA test?
    4. How would we go about narrowing down which generation the mutation occurred?
    5. If the final panel with the 67 markers comes back and totally match does it tighten the connection and lower the distance to the most common ancestor?
    6. Not being ready concede errors in our research, i.e. paper trail, (yet!) If this was your family, what would be the next step you would do to try to reconcile these results?
    7. I know getting more family members tested would help. Would it be more beneficial to get a descendant of a different son of Edward the common ancestor to test or is there a benefit to getting more descendants in our own branch to test, such as one generation back?

    I know these are a lot of questions, but I would appreciate any suggestions. There are a lot of smart people on this board. It's all as clear as mud to me. Kindest regards, Ann (daughter of participant)

  • #2
    ysearch

    Not sure if it is needed but my ysearch sign-in is 3JPXX.
    Thanks Ann

    Comment


    • #3
      It is not certain that your common ancestor goes back exactly eight generations just because they have the same given name. Given names tend to run in families (probably moreso in the past when parents were less "inventive" in naming their children). It could be that the two ancestors with the same given name were cousins. On the other hand, you and your match undoubtedly come from the same family. Since the differing mutations probably happened generations ago there is no easy way to identify when they appeared.
      Last edited by josh w.; 17 July 2007, 07:39 PM.

      Comment


      • #4
        Is it possible?

        Thank you for your response, Josh. But assume that research (other than a common name) showed Edward was indeed our first common ancestor and he is 8 generations away from both men, descendants of two different sons of Edward abt 1735. Are the DNA results saying it is not possible? Ann

        Comment


        • #5
          Originally posted by dreamerntn
          Hello
          I am hoping that some of you hear can help explain the results of my DNA testing.
          This is the paper trail for my match and I, both with last name Mozley. (My father's DNA was used, of course). We are very confidant in our research as it is the result of years of independent work. Though we have never met, I have no doubt we are related. My question concerns the distance to the most recent common ancestor.

          The paper trail is as follows:
          Edward Mozley (b abt 1735)> Edwin> Samuel G.> Isaiah Irvin> Mozley> Mozley > Mozley> Living Mozley.

          Edward Mozley (b abt 1735)> James H,> Caleb Turner> James Madison> Mozley> Mozley > Mozley> Living Mozley
          Note that both men tested are 7 generations away from the common ancestor.
          Now I am left with trying to reconcile this research with the DNA results.

          Edward Mozley b abt 1735, sold 200acres Bedford Co. VA 1788
          Halotype:
          65905 - R1a1 deep tested; 93067 - R1a (being deep tested now)

          PANEL 1
          DYS# 393 390 19* 391 385a 385b 426 388 439 389-1 392 389-2
          Kit #
          65905 Alleles 13 25 15 11 10 14 12 12 10 12 11 31
          93067 Alleles 13 25 15 11 9 14 12 12 10 12 11 30

          PANEL 2
          DYS# 458 459a 459b 455 454 447 437 448 449 464a** 464b** 464c** 464d**
          Kit #
          65905 Alleles 15 9 10 11 11 24 15 20 33 12 15 15 16
          93067 Alleles 15 9 10 11 11 24 15 20 33 12 15 15 16

          PANEL 3
          DYS# 460 GATA H4 YCA II a YCA II b 456 607 576 570 CDY a CDY b 442 438
          65905 Alleles 11 11 20 23 17 15 18 18 34 36 14 11
          93067 Alleles 11 11 20 23 17 15 18 18 34 37 14 11

          Using the FTDNATIP calculator if we plug in that we could not have shared a common ancestor in the last 6 generations (which we know is true) there is 10.89% chance we share a common ancestor in the last 7 generations, a 22.33% chance in the last 8.
          At 20 generations back we reach 95%.
          Yet our paper trail research says our common ancestor is indeed 8 generations back.
          I am retesting the 3 markers on which we differ.
          We are both expanding our testing to 67 markers.
          I have ordered the deep testing on the halotype group for my kit.
          There are two things to consider when dealing with your specific situation. All calculations are based on Time to Most Recent Common Ancestor (TMCRA). That formula is in turn based on studies of mutation rates between fathers and sons. These calculations are done for each marker, which do have different mutation rates. Some are fast and some are slow.

          Keeping that in mind, realize that the mutation rates used to determine TMRCA are average rates. This means that most people will be close to this rate. It also means that x%, a low number, will be at the high end of mutation rates, "fast mutators," and y%, another low number, will be at the low end of mutation rates, "slow mutators." (However, this is all just random as far as we can tell.) When FTDNATIP places what seems to be the correct paper trail common ancestor at 22% probability, this may just mean that the random events of mutations within your paternal line place it near the high end of mutation rates. So FTDNATIP is overestimating the TMRCA by using the average mutation rates. Most people use the 50% level of probability as the default, since it's in the middle of the range of probabilities. While 95% probability may place the common ancestor 20 generations back, 50% may place it 11 or 12, which is not far off your paper trail evidence of 8 generations. So, it's entirely possible that your paper trail and the DNA results are both right.

          The other question is on which 3 markers do the two lines differ. This gets to the question of fast vs. slow markers. In your case two of the three differing markers, 385b and CDYb, are regarded as a couple of the "fastest" markers in the first 37 with the highest mutation rates. The third one in your case is regarded as a relatively slow one. Based on that, again, I think that it's quite likely that both your paper trail and the DNA results have it right.

          Comment


          • #6
            I agree with MMaddi here. You have a paper trial linking him in as being the son. How solid that paper trail is I don't know but will take your word that it is solid.

            Having a solid paper trail linking the 2 brothers as being sons of Edward, and there only being a 7 generation distance between the 2 participants. 4 mutations does seem to be a bit much and I too would have questioned that had it been me in that situation.

            In 7 generations, i'd have expected more like 1 or 2 mutations. You are on the right track here though, you went back to the 6th ( or 7th?) generation and got 2 of the sons branches tested, that is exactly the right thing to be doing.
            If Edward had other sons, my next step would be to trace down living male descendants of the other sons branches and get them to test.

            I would also be searching for more descendants of James and Edwin so you have more tested from the same branch to compare to.
            The " in between'ers" might help explain the higher number of unexpected mutations.
            I have one cousin who has a 2 step mutation differnce on one of his markers compared to the rest of us cousins. That I wasn't expecting either lol.

            I agree with MMaddi on this, you have a paper trial and you actually have a good match at the highest level, there is just 4 mutations between the 2 branches. Keep searching for cousins to get tested, one of them could hold the answer.


            Don

            Comment


            • #7
              Thank you Mike and Don. I appreciate you taking the time to wade through my long post and respond. Statistics in college was not my strong point but I think too that we are just on the edge of the curve if that would apply here. Though I am not sure that the following applies in my case, I also have read with interest the following thread discussing how certain markers are reported differently by the different labs that do the test.
              http://genforum.genealogy.com/dna/messages/1383.html

              One gave examples of cousins upset with results at one lab tested else where and the mismatches disappeared. Two of my markers that were off are addressesd as having this problem. I do not fully understand it, but it was interesting reading. I will wait for the 67 results to come back and search for more participants.
              Now Don.... I only have have 3 mismatches, not 4, lol . Don't make me suffer more than I have to.... Thank you again Ann

              Comment


              • #8
                Agree with Mike and Don that your family records and the genetic estimates are really not discrepant. For example, I have a 36/37 match which suggests a common ancestor around 200 to 250 years ago. However based on a limited amount of information it is quite unlikely that the ancestor lived after the 1600s.

                Comment


                • #9
                  P.S. the MRCA estimates were not off in my example. The estimates provided on your "tip" page are actually based on liberal assumptions of when the MRCA could have lived. It is possible to recalculate the estimates based on more conservative assumptions. The net effect is to push the MRCA further back in time. In my example, recalculating the estimate produced a closer match between genetics and known history. (Technically the Bayesian formulas produce a family of curves depending the liberality or conservativeness of ones assumptions. The assumptions in turn depend on known family history and are not completely arbitrary-- it seems circular but it is just iteration, i.e. fine tuning).
                  Last edited by josh w.; 18 July 2007, 10:09 PM.

                  Comment


                  • #10
                    Update

                    Just wanted to update:
                    Google "Bruce Walsh" and you'll find an array of articles about estimating the Time to the Most Recent Common Ancestor for the Y chromosome for a Pair of Individuals.. He designed the Time to Most Recent Common Ancestry Calculator and is the Chief Population Geneticist for Family Tree DNA. The following is his response to my letter to him:

                    Hi Ann:

                    Think there is an easy answer to this

                    "If there is only 22% chance of our MCRA being within the last 8 generations, is it possible that we just happen to lie on the edge of the curve and our common ancestor being within 7 generations is still congruent with the results of the DNA test?"

                    YES! 22% chance means that one in five people will contact me with this
                    question!

                    Cheers

                    bruce


                    So Bruce agrees with all of you who answered this post here at FTDNA ... we are the one out of 5 whose ancestor WILL lie within 7 generations. Our upgrades are still pending...
                    Last edited by dreamerntn; 20 August 2007, 01:27 AM.

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