Announcement

Collapse
No announcement yet.

In Common With

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

  • In Common With

    Excuse me if this has been posted before but my mind is mush trying to figure this out. It's all so overwhelming.
    When I run the "In Common With" the chromosomes don't line up the same. One person might be on one chromosome and then another on a different chromosome. Shouldn't we all share the same spot on the same chromosome? Then when there are trees I can never find common surnames. Am I looking at it all wrong?
    I'm trying to find my great grandfather's true surname as he was given his mothers. I'm having no luck, possibly because I'm not looking at it right.
    Thanks

  • #2
    Originally posted by faith196237 View Post
    Excuse me if this has been posted before but my mind is mush trying to figure this out. It's all so overwhelming.
    When I run the "In Common With" the chromosomes don't line up the same. One person might be on one chromosome and then another on a different chromosome. Shouldn't we all share the same spot on the same chromosome? Then when there are trees I can never find common surnames. Am I looking at it all wrong?
    I'm trying to find my great grandfather's true surname as he was given his mothers. I'm having no luck, possibly because I'm not looking at it right.
    Thanks

    When you run in common with (for example) Mary Smith, you get the set of people that both you and Mary are related to. It may be that Mary is related to John Doe for the same reason that you are related to John Doe, but it might also be the case that Mary is related to John Doe through a different route.
    It might also be the case that you and Mary Smith are both related to John Doe's mother, but you are related on chromosome 18, and Mary is related on chromosome 19.
    If you are trying to prove a common ancestor, then it is extremely lucky if you, Mary Smith, and John Doe all happen to share the same bit of a chromosome, and that you all match each other. Read up about triangulation--FTDNA does not offer triangulation, but with long enough segment matches in common, it's probably not needed.

    It is hard to figure out an unnamed great-great-grandfather from DNA on FamilyTreeDNA. It's much easier on Ancestry--if the relevant people have tested. With Ancestry, people have better family trees.

    Look at dnaadoption.com, even though your case is much older than most. Look at how to do mirror trees on Ancestry.

    For general matching, it's much harder than people think to find 4th cousins or so. You have to build the best family tree you can going back about 5 generations. Then when you get a match, you have to build that person's tree, if they haven't already. Each of you will have 64 great-great-great-grandparents on each side (except for the ones you can't name yet). Then you find the common great-great-great-grandparents, and work down from there. If you are very lucky, you might get a second cousin match that can guide you to your great-great-grandfather.

    Comment


    • #3
      And in addition, it is more difficult to find cousins because we will generally NOT share dna with the following:

      90% of 5th cousins
      50% of 4th cousins
      10% of 3rd cousins

      These percentages will vary according to others.

      Comment


      • #4
        Thank you

        Thank you for the replies, you've explained it very well. I am a member on Ancestry and will keep looking there and check out the adoption site. You both are awesome in explaining. Thank you again.

        Comment

        Working...
        X