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Double Relationships

Replies: 6

Re: Double Relationships

Posted: 21 Oct 2013 8:03PM GMT
Classification: Query
I wouldnt say that Ancestry DNA (or any other company) has the ability to "find" a relationship. The results "suggest" a relationship, but it is a range in which a number of relationships might fit. For example, shared dna of 50% could predict a mother, father, or sibling. a 25% shared dna amount might suggest grandparents, aunt or uncles, half-siblings, or double cousins.

In the instance you describe, if I am understanding you correctly, you are wondering about the percentage shared by a child produced by two siblings, correct? As I understand it, the amount of shared dna would still be 50%, so the child would be within the range of a child of both parents (siblings), but there would be a greater amount of dna shared with the grandparents (siblings' parents) than normally would be expected of a grandparent/grandchild of 25% shared. I've never been good at math, but I think the shared dna percentage between the grandparents and grandchild would be that of parents...50%.

I could be totally off base on this one, so I would hope someone else might add to it. Lest anyone think this is too "out there", one of my matches grandfather happens to be the son of two siblings.
SubjectAuthorDate Posted
atware 21 Oct 2013 1:35AM GMT 
twotzus 22 Oct 2013 2:03AM GMT 
S_H999 22 Oct 2013 3:46AM GMT 
atware 22 Oct 2013 11:07AM GMT 
twotzus 22 Oct 2013 4:09PM GMT 
twotzus 22 Oct 2013 4:27PM GMT 
atware 23 Oct 2013 12:08AM GMT 
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