How to find a theoretical family member

Just discovered this program and looking for some help. I am wondering if this program can do what I am asking…

I am working DNA profiles and family trees for people who are orphans/adopted. I was wondering if it is possible for Gramps to show me where a theoretical person should be in a family tree. For instance: I have a DNA matches that say that a person is a 3rd cousin. Another person is 1-2nd cousin. Another person is a 1-2 second and so on. I have been able to build a tree showing where those people are in the tree. but I am having difficulty in some cases figuring out where my adoptee would fall into the tree as I know that I don’t always have all the people in the tree.

Is there a way to tell Gramps “Who is, or where would a person be in the family tree, that is related to person #1, 2 and 3?” That make sense?

I am hoping that with an open source program that this would be something that could be done. Thank for any and all help.

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Not sure as I have not done a DNA test yet.

Maybe read this 2020 discussion Gramps and recording and comparing DNA-matches

And install and give the DNA Segment Map Gramplet addon a try as it uses Association’s to link people.

You’re asking if Gramps has Genetic or Genealogical Triangulation analysis as a built-in feature?

No, not as such. You might be able to simulate the Triangulation functionality by building a complex Custom Filter and graphing. The Relationship path between bookmarked persons seems like a starting fillter rule.

A scholarly article on the subject can be found at: “Identification of Anonymous DNA Using Genealogical
Triangulation

Or, for one more focused on distance & direction rather than direct matching of centemeres (and more adaptable to genealogical trees): DNA Triangulation

No, Gramps can’t show you where someone could be in a family tree if they aren’t connected. The information you get from DNA matches is incomplete (e.g. false-positive and false-negative segments, as well as relatives who don’t cary any DNA which matches with yours) and people are hard to locate depending on the family tree structure, especially if the tree is incomplete.

Just an example: I have 74 2nd cousins in my family tree (which should be all of them) and there are probably 100+ 3rd cousins of which I only have 20 in my tree. A DNA match of someone adopted telling me they are 2nd or 3rd cousins would be impossible to locate just from that information. I’d need more relatives tested which are closer to the match to locate them in the family tree.

The WATO tool on https://dnapainter.com/tools/probability may be helpful.

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