Triangulation when descending through multiple siblings.

Question

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I have traced my line back to Richard Stout (Stout-60) and Penelope Kent (Kent-214)

But I actually descend through two of their children Jonathan Stout (Stout-1166) and David Stout (Stout-115)

I have found 2 DNA matches on Ch. 9 on the same place for 12.9cM with trails to Richard and Penelope Stout.  One is through their son Peter (Stout-139) , but the other is through their son David from whom I also descend.

For Triangulation do I need to find another distant cousin who descends from a different sibling that I am not related to? Or is three siblings (i.e. Jonathan, David, Peter) enough?

Comments

Hi Jonathan,

My understanding of WikiTree's concept of triangulation for DNA confirmation is that it's based on segment triangulation to confirm relationships from you and each of your matches up to the Most Recent Common Ancestor's children. If you have multiple descent lines documented from an MRCA, that becomes problematic when trying to confirm the relationships from you to the MRCA's children. How would you know from which of your ancestral paths to the MRCA that you inherited the DNA segment in question in order to confirm your particular relationships up to the MRCA's children?

Answer 1

Not an expert but I believe any two cousins will do but from different siblings helps.I think they have to be the same relationship though as two 3rd cousins 1x removed or two 4th cousins but not a 3rd 1x and a 4th.

Answer 2

Hi, good question.  I think you would want three cousins who all descend from the most common recent ancestor via different children of the ancestor.

Once you go a level deeper into the research and start looking at each TG and then you can see that you may share various segments of DNA with a cousin via an ancestor but then each of those TG groups will be from different ancestors further back on the tree or maybe way back.  

And then I get to thinking about the Triangulation Groups between my various cousins or that my parents have that I don't have that go back to various ancestors that I am researching. It can start to get complicated pretty quick.

I have been using dnapainter.com and also yourDNA.family which have both helped me to learn a lot more about genetic genealogy as I continue the study.  

Good luck!

Comments

I am descended from three Doub brothers born in the early 19th century, sons of the same John Doub who first came to the USA, and since both my mother and father were descended from them it makes both DNA relationships and family tree displays difficult for sites. We worked it out in the family that my parents were first cousins once removed, but there were other relationships as well. My siblings and I were LUCKY!