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Old 02-03-22, 07:36
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Default Are we really connected?

If you have 8% cM and less than 1% shared DNA……..5th to 8th cousin, are you always related? Or can some DNA be shared by people who are not related until they get back to Adam and Eve?
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Old 02-03-22, 08:27
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An 8th cousin argues an ancestor born probably c 1700 or even much earlier. Potentially over 500 ancestors in that generation. I doubt that even the Queen could name every single one of her ancestors that far back. So I don't think you could argue you are NOT related to somebody, simply because you can't find the link.
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Old 02-03-22, 10:24
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Quote:
Originally Posted by Phoenix View Post
An 8th cousin argues an ancestor born probably c 1700 or even much earlier. Potentially over 500 ancestors in that generation. I doubt that even the Queen could name every single one of her ancestors that far back. So I don't think you could argue you are NOT related to somebody, simply because you can't find the link.
Maybe I didn’t word that question well…… I’m more wondering if there could be others out there who have that much of the same DNA but are not related.
I was reading about this research into genetics where the researchers found people who were quite close genetically but they could not find any family relationship. One was a very English lady in Devon who was very fair in colouring, tiny, sweet lady. Genetically close was an Australian Aboriginal man. Once again completely different in appearance and background.
I suppose I’m a bit annoyed at having so many of these people in my DNA matches and they have no trees……so no way of connecting us. They also do not answer messages.
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Old 02-03-22, 10:39
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Surely the Australian Aboriginal man could have a bit of DNA from a white ancestor?
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Old 02-03-22, 10:54
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If a gene mutates randomly, then there has to be the possibility that two people will have bits of identical DNA which they have acquired independently. What I don't know is how many cM the DNA has to be before you cannot put it down to chance, but must accept a relationship.
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Old 02-03-22, 13:36
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Originally Posted by kiterunner View Post
Surely the Australian Aboriginal man could have a bit of DNA from a white ancestor?
Indeed especially with the amount of transported convicts. I expect if the lady traces her ancestors back there's a convict in there somewhere.

I have found another two, siblings of a direct ancestor.
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Old 07-03-22, 22:19
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I guess my question is more…….could anyone get 8cM and less than 1% shared DNA with a person not related or related so far back, as in the Stone Age?
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Old 07-03-22, 22:48
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You might like to read this, Libby:

https://lianejensenresearch.com/2017...lse-positives/
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Old 08-03-22, 01:23
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Thank you. That answers my question. I have a few of 8cM and a couple cannot find any connection. I know there could be the unknown adoption, surprise baby, but I also think some are not really related to me, just randoms.
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Old 09-03-22, 01:43
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Blaine is really knowledgeable, he has an FB group and he is also very lovely. That article explains what I was badly trying to work out how to say in my head.

Mind you do look at the ones with trees. I have a 7cm match and assuming her tree is accurate (I haven't looked closely but have no reason to doubt at this point) we match on a single 5g grandmother only. She married 3 times and we descend from different husbands. I should look into that more now I know a bit more about DNA but it was exciting to pinpoint 1 exact relative that we match on.
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