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General => Ancestral Family Tree DNA Testing => Topic started by: geordiewesterby on Thursday 14 May 20 10:17 BST (UK)

Title: DNA testing
Post by: geordiewesterby on Thursday 14 May 20 10:17 BST (UK)
I have to admit that I don't know very much about DNA testing and I can see from posts on here that people are well into it. So here is my dilemma. I have a second cousin. She is descended from Thomas Drummond who was her great grandfather. The line goes like this: Thomas Drummond - Margaret Drummond - Sarah her daughter - Tracy my 2nd cousin. We are trying to ascertain whether I am descended from him or not: Thomas Drummond - Charlotte Drummond - John her son - Me.

We don't think that Thomas Drummond fathered Charlotte, so we think that Charlotte Drummond and Margaret Drummond were half-sister as opposed to being full sisters (they definitely had the same mother).

Would a one of these Ancestry DNA tests for me and one for Tracy determine that does anyone know, or it is a waste of money as you can't really determine that?

Title: Re: DNA testing
Post by: Gadget on Thursday 14 May 20 10:32 BST (UK)
It would be likely to give you a good idea of your relationship with her if you both tested with the same firm.

See this for the possible range of shared DNA for various relationships:

https://dnapainter.com/tools/sharedcmv4

The amount that I share with my second cousins does vary quite a lot within the range given.


Gadget
Title: Re: DNA testing
Post by: Craclyn on Thursday 14 May 20 15:36 BST (UK)
You would need to put a bit of time and effort into understanding and following up the results, but it should give you a very good starting point for solving your question.