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General => Ancestral Family Tree DNA Testing => Topic started by: littleliz02 on Friday 21 February 25 10:41 GMT (UK)

Title: Which Grandparents do we share - DNA match
Post by: littleliz02 on Friday 21 February 25 10:41 GMT (UK)
Hi, My apologise if this is a really basic question, but I am struggling a little. I have a connected for potential illegitimate Gr grandfather, I have a matched DNA test on ancestry for

2nd cousin 1x removed or half 2nd Cousin - 2% shared DNA: 160cM across 6 segments.

I am trying to build their tree on ancestry, to work it out but I cant work out which set of grandparents we would share.  Could anyone tell me which grand or great grandparents we would share?
Title: Re: Which Grandparents do we share - DNA match
Post by: Spelk on Friday 21 February 25 11:04 GMT (UK)
Have you looked at Shared Matches?
This is where you have cousins or second cousins who also match with the unknown match. You know where the cousins come from so if they match with the unknown they must share that line.
Added - if you have not done so already put your DNA on other sites such as MyHeritage etc as you may have other matches there.
Title: Re: Which Grandparents do we share - DNA match
Post by: littleliz02 on Friday 21 February 25 11:26 GMT (UK)
Yes, I have looked at shared matches importunely the close match is also illegitimate so that hasnt helped.  I was looking to start a tree with them and me and if I know which grandparents we share that would help, but I cant work it out so hoping that someone could tell me which set of grandparents it is likely to be be.
Title: Re: Which Grandparents do we share - DNA match
Post by: Spelk on Friday 21 February 25 11:43 GMT (UK)
Have you made contact with your Match and swapped with them what matches you both have?
Did the Match do the DNA test to locate their missing parent(s) or just for the fun of finding their ethnicity?
Title: Re: Which Grandparents do we share - DNA match
Post by: SouthseaSteel on Friday 21 February 25 17:02 GMT (UK)

Agree, Shared Matches, other platforms and direct comms with are the only way forward.

Given your unfortunate situation re your significant connection I would suggest you build trees for all possible grandparents and look for potential scenarios re time and place etc.

Good luck
Title: Re: Which Grandparents do we share - DNA match
Post by: littleliz02 on Friday 21 February 25 18:10 GMT (UK)
Thank your advice... I have created a number of trees on both connected and mine... I just asked for advice on which potential grandparents we would share

 2nd cousin 1x removed or half 2nd Cousin - 2% shared DNA: 160cM across 6 segments
Title: Re: Which Grandparents do we share - DNA match
Post by: g eli on Friday 21 February 25 18:23 GMT (UK)
Can you see which parent the results show. If they are 1 or2 do you know which side of the family they are on.
e.g.I have a match but don't know how they connect, I start by seeing if the connections match anyone that I know how they are connected. I then select parent 1 matches if they are there then parent 1 is the connection if not I try parent 2. You now know which side of the family you are looking at. Unfortunately this only works if the person is 1 or 2 not both sides or undecided.
Title: Re: Which Grandparents do we share - DNA match
Post by: familydar on Friday 21 February 25 19:05 GMT (UK)
The shared cM tool on DNA painter will give you an idea of whether you should be looking at GGPs or a generation further back.  Your own age and that of your match will also come into play.  If there is a significant difference in your ages you could be looking at a once or even twice removed relationship to one another.

Full 2nd cousins share a pair of GGPs (husband AND wife).  Half 2Cs would share only one GGP (husband OR wife).  2C1R means the shared ancestor couple is GGP to one of you and a generation further back (GGGP) for the other.

Jane :-)
Title: Re: Which Grandparents do we share - DNA match
Post by: Glen in Tinsel Kni on Friday 21 February 25 19:12 GMT (UK)
The predicted relationship is just a prediction and can't be relied on. There are more than a dozen possible relationships for a match of 160cM and the common ancestor could be as far back as one of your 4x Great-Grandparents but they could be a removed first cousin so the common ancestor could be one of your grandparents.

The shared cM figure alone two people share isn't enough to work out most mystery matches and  it's important to  look at shared matches and check the shared cM amounts in all directions. The different perspective can often rule out certain relationships to matches and helps to build a more accurate tree.
Title: Re: Which Grandparents do we share - DNA match
Post by: Steve3180 on Friday 21 February 25 20:26 GMT (UK)
The amount of dna you share with somebody gives you a very approximate distance back to the common ancestor, in this case probably a great grandparent or a great great grandparent but it could be further back. What it doesn't give you is a direction, so which of the grandparents, for that you have to triangulate with your known 2nd and 3rd cousins.
Title: *SOLVED* Which Grandparents do we share - DNA match
Post by: littleliz02 on Saturday 22 February 25 09:32 GMT (UK)
Thank you for your help, luckily I know that the match is from Paternal side.  Based on advise and the DNA tool I think my start would be great great grandparents and build tress from there.  Thanks again