A reminder about relationships:
If A and B are both related to C, that does not mean that A and B are necessarily related to each other. A and B could be related, but they do not have to be related to each other simply because they share C as a relative.
My Mom and my Dad were both related to a person named Mary Anne. My Mom and Dad were not related to each other at all. Mom was related to Mary Anne’s dad and my Dad was related to Mary Anne’s mother.
Always stop and think about what relationships are implied by relationships and which relationships are not. And remember–sometimes our own family makes good examples and sometimes they do not.
3 Responses
Question: On Ancestry, if A is a DNA match to B, A is a DNA match to C, and B is a DNA match to C, what does this tell you? You can’t see the chromosome overlap, but can it help you in any way? Thank you!
Without a chromosome browser, probably nothing. It would depend though upon how much DNA was shared among them (if the amount suggested half or full siblings). If the shared cMs are suggestive of a more distant relationship, it would not really help without other information. I have quite a few matches of this type where B and C share a relationship with each other besides the one they share with me.
Thank you. I guess I will have to try and figure out these matches on Ancestry a different way.