Announcement

Collapse
No announcement yet.

What about this match please?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • What about this match please?

    Hello!

    On Gedmatch, here is all the connection before triangulation that I have with a woman :
    chromosome 1 : 9.2CM
    chromosome 6-1 : 7.1CM
    chromosome 6-2 : 8.9CM

    The triangulation in Gedmatch gives this, in B37 (I also give B36 and B38):

    1 Segment of chromosome 1: 11 correspondences (7.6CM, 7.4, 7.4, 7.3, 7.3, 7.1, 7.1, 7, 7, 7)
    B36 : 11 correspondences, from 7CM to 7.6CM (7.6CM, 7.4, 7.4, 7.3, 7.3, 7.1, 7.1, 7, 7, 7)
    B38: 11 correspondences, from 7CM to 7.6CM (7.6CM, 7.4, 7.4, 7.3, 7.3, 7.1, 7.1, 7, 7, 7)

    1 Segment of chromosome 6-1: 6 correspondences (6.9CM, 6.9, 6.9, 6.7, 6.6, 6.6)
    B36: 6 correspondences ranging from 6.6CM to 6.9CM. (6.9CM, 6.9, 6.9, 6.7, 6.6, 6.6)
    B38 : 6 correspondences ranging from 6.6CM to 6.9CM (6.9CM, 6.9, 6.9, 6.7, 6.6, 6.6)
    => All below 7CM. That's really borderline for the 6.9! Should we take this into account?

    1 Segment of chromosome 6-2 (with 2 correspondences) => 8.7CM (for the 1st match which is really interesting) and 6.7CM (for the 2nd).
    B36 : 2 correspondences. Same as B37.
    B38 : 2 correspondences. Same as B37.

    => So 3 segments including 2 on the same chromosome 6 (6-1 and 6-2).

    I can provide you with my .docx and .csv file summarizing all the triangulation with this match if you wish for a better analysis!

    So my question is : Is there any cousinship or not (Close or distant by centuries, whatever.)? And if cousinship, I have to go back to how many centuries or so to facilitate my research in classical genealogy?

    My 2nd question concerns the length of the segment before and after triangulation: Knowing that the result of a triangulation can change according to new dna samples that arrive. If before triangulation, I have a 15CM segment, but after triangulation I only see a length of 8CM for the same segment, can we say that the 15CM segment can be true under the condition that new samples can confirm the entire segment? Or simply stick to the triangulation of the moment, knowing that going from 15CM to 8CM, classical genealogy research can take us even further back in time, and more than necessary, because we can be wrong by several generations. Going from 15CM to 8CM, it's double!

    Thanks for the reply

    PS : I received the complete family tree of this person (But only the father's side, it is 1400 years old!).

    PS 2: I discovered on Gedmatch that I was matching with other people (3 especially) who I know are cousins with this woman I am related to (I recognize them by their typical surname and recognized as cousins in classical genealogy). I share with these 3 persons only 1 segment of 10.5CM for the first one, 10.8CM for the second one and 7.4CM for the third one, so common ancestors which make me think that there is a cousinhood. These 3 persons belong to 3 other sub-branches of this woman with whom I match. On Gedmatch, there is no segment in common between these 3 persons and the woman of the present study. Not to mention the study with the G25 and the stories gleaned from my family about our common past (common geographic location, etc). I am trying to give you as much information as possible in order to better conclude on this case.

    PS 3: These 2 people mentioned above (10.8CM and 7.4CM) share only 1 segment between them, after checking on Gedmatch (one to one autosom, chromosome 3). I will talk about the 10.8CM connection (I match on this same chromosome 6 on 1 segment but in another place than the ones mentioned above), after solving the case of the present post. I will also talk about the other 2. They will help me a lot in cross-referencing in classical genealogy when I get their full tree back.

  • #2
    Sorry, forgot this (for more details) :

    An interesting fact : I match on 1 segment with a male on 10.8CM (8.8CM after triangulation. maybe this will increase after new "compatible arrivals" arrive). For this case (which I will elaborate on later), I also match on this 6-2 chromosome, but on a segment right next to the segment I share with this woman. And I know, by classical genealogy, that this woman and this man are distant cousins (sure and certain). But they do not share any genetic segments with each other on Gedmatch. I wanted to point this out.

    Comment


    • #3
      The only segment lengths I use on GEDmatch are those that are produced by the One-to-One Comparison tool using the default parameters plus the "Prevent Hard Breaks" option. The One-to-One tool actually compares individual SNP scores. Many of the other tools do not; instead, they make use of GEDmatch "batch processing" results, which are based on a smaller set of SNP's in a way that greatly speeds processing when it is necessary to compare one kit against all others (as is the case for Triangulation, One-to-Many, etc.). The One-to-One tool is the gold standard for GEDmatch.

      Comment


      • #4
        Originally posted by John McCoy View Post
        The only segment lengths I use on GEDmatch are those that are produced by the One-to-One Comparison tool using the default parameters plus the "Prevent Hard Breaks" option. The One-to-One tool actually compares individual SNP scores. Many of the other tools do not; instead, they make use of GEDmatch "batch processing" results, which are based on a smaller set of SNP's in a way that greatly speeds processing when it is necessary to compare one kit against all others (as is the case for Triangulation, One-to-Many, etc.). The One-to-One tool is the gold standard for GEDmatch.
        Hello John!

        Thank you for your reply! Ok, I understand!
        here is the one to one with the option "prevent hard breaks" :
        Chr B36 Start Pos'n B36 End Pos'n B37 Start Pos'n B37 End Pos'n B38 Start Pos'n B38 End Pos'n Centimorgans (cM) SNP's
        1 - 33 844 112 - 39 957 320 - 34 071 525 - 40 184 733 - 33 605 925 - 39 719 061 - 9,2CM - 359
        6 - 41 474 558 - 44 676 718 - 41 366 580 - 44 568 740 - 41 398 842 - 44 601 003 - 7,1CM - 227
        6 - 166 604 647 - 170 177 492 - 166 684 657 - 170 335 567 - 166 271 169 - 170 020 343 - 8,9CM - 269

        Estimated number of generations to MRCA = 5.4

        What do you think about this match please? Is there a TRUE connexion or not please? If true, this MRCA is correct, how many generations is our common ancestor?

        thank you so much (this match is very important for me. I don't want to do a mistake)!

        Comment


        • #5
          Basically, it is a very nice maybe.

          At those lengths, there is a good chance the match is Identicaj By Chance and a good chance it is Identical By Descent - but think the percents say more likely by Descent

          Are you part of an Endogamous population?

          Comment


          • #6
            Originally posted by loobster View Post
            Basically, it is a very nice maybe.

            At those lengths, there is a good chance the match is Identicaj By Chance and a good chance it is Identical By Descent - but think the percents say more likely by Descent

            Are you part of an Endogamous population?
            Hello!

            Ok, maybe or not (not sure), I understand!

            For the endogamous population, yes it's possible, because I'm originary from Morocco (Marriage within the same tribe is quite common).
            Switch
            FTDNA Customer
            Last edited by Switch; 12 January 2022, 03:17 PM.

            Comment


            • #7
              I said that for endogamous population, it is possible, but for this match, I really don't know.

              Comment

              Working...
              X