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General => Ancestral Family Tree DNA Testing => Topic started by: Spidermonkey on Tuesday 29 August 17 10:50 BST (UK)

Title: Triangulating and ruling out family lines
Post by: Spidermonkey on Tuesday 29 August 17 10:50 BST (UK)

Through using both Ancestry and gedmatch, I have found a person (I shall call them Mrs A) to whom my DNA sample links with (ancestry gives 4 - 6 generations, gedmatch gives 4.8).

We have both searched out trees, but can't find a suitable connecting person (or even name), so acknowledging that there might have been duff research or illegitimacy etc we have looked for others who are shared matches to both of us.  Whilst we try to make contact with those, can I start to rule out family lines where I have a match with someone, but Mrs A doesn't? e.g. Miss B and I have a shared  gt gt gt grandad but Miss B and Mrs A don't show up as a connected (on either Ancestry or gedmatch).

Ouch, this hurts  ::)

Title: Re: Triangulating and ruling out family lines
Post by: Jan_A on Wednesday 30 August 17 04:37 BST (UK)

Hi!
If you would like some help, please  provide gedmatch kit #s and where I can find you on ancestry.com.

I love a good mystery.  I have found MANY mysteries in my family tree as that my father's mother's side had a "Diehl" in it and when my grandmother had an affair and created my father..it appears that about 1/8th of the Diehl families have also done so... I am having fun "isolating" family branches to narrow down how people are related.

Jan

shhhh I better watch it - WE may be related  ha ha ha

Title: Re: Triangulating and ruling out family lines
Post by: sarah on Wednesday 30 August 17 09:23 BST (UK)

Hi Jan,

Welcome to RootsChat

You have just replied to spidermonkey's topic here but he didn't mention any family names. What family members do you see a connection with ?

Regards

Sarah

Title: Re: Triangulating and ruling out family lines
Post by: familydar on Wednesday 30 August 17 10:32 BST (UK)

Nice idea but I think the 3xGGF shared by you and Miss B is probably too far back to be able to definitely rule out that line.

We each inherit roughly half of our DNA from each parent, so there's half we don't inherit.  Go back to grandparents and there's three quarters we don't inherit.  Extrapolate to 3xGGF and that's a very big proportion of his DNA that you won't inherit and you are very lucky to have got a DNA hit with someone who has inherited sufficient of the same tiny sequence of DNA as you have.

In theory (although I don't know if it's ever happened in practice) and if I understand correctly, you and a full sibling could have no DNA commonality except for your X/Y chromosomes.

If you and Mrs A have both worked all lines of your trees back to 4xGGP (to give you the six generation link suggested by Ancestry) and there are no names or locations (illegitimacy) common to both then you should start looking for multiple relationships further back.

Jane :-)

Title: Re: Triangulating and ruling out family lines
Post by: Spidermonkey on Wednesday 30 August 17 11:45 BST (UK)

Thanks Jane for your comprehensive answer - I guess I'll just have to keep niggling until something shakes loose!

Title: Re: Triangulating and ruling out family lines
Post by: familydar on Wednesday 30 August 17 12:55 BST (UK)

Quote from: Spidermonkey on Wednesday 30 August 17 11:45 BST (UK)

keep niggling until something shakes loose!

You and me both!

Jane :-)

Title: Re: Triangulating and ruling out family lines
Post by: Jan_A on Wednesday 30 August 17 19:14 BST (UK)

Sarah, not sure that we are related, just offering services to help find family :)

Jan