DNA not a match?

Question

Very confused. I've traced my ancestor to my 4x great grandfather and the person that's connected to that person is not a DNA match. Does this mean we have our trees wrong? I'm well sourced so I'm confused as to why we aren't matching.

Answer 1

No worries!

If you and another person have the same 4x great grandfather, the two of you are 5th cousins. The chance of finding an autosomal DNA match with a 5th cousin is rather small.

As the message on that page says, it is reasonable likely that a  test-taker will share DNA with their 5x great grandparent, but the chance of two 5x great grandchildren on different lines having the same piece(s) of DNA from that person is small.

Comments

Also, it looks like you and the other DNA tester trace your descent to different wives of this man, so you are really just half-fifth cousins. That further reduces the chance of seeing a match.

Answer 2

My Dad has at least five matches on gedmatch that are estimated at less than 5 generations, but who don't match me at the standard 7cM limit. If you have grandparents still alive get them tested.

Comments

The grandparent I have left on that side is refusing to test. She and her family aren't on good terms. Sadly, there's no way I can convince her.

Answer 3

Hi, Lisa. I assume you're looking at autosomal DNA. In which case, another contemporary descendant of your 4g-grandfather William Hawkins would make the two of you 5th cousins. And at that number of degree-of-relationship separations--12 birth events between you and your cousin--autosomal DNA really can't be used as evidence one way or the other.

Fifth cousins would share a mathematical, theoretical average of 0.0488% of their DNA. From a practical perspective, it's likely that the amount shared is too small to even be detectable. A nifty study by Brenna Henn, et al., showed that there is less than a 15% chance that 5th cousins would share any detectable autosomal DNA at all.

Some folks feel that with extensive triangulation autosomal DNA can be used as evidence to the 5th-cousin level. But a lot of knowledgeable people disagree with that. At the very least, though, a non-match with a 5th cousin really means nothing.

Comments

Once again, I'm too slow....  :-)

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It was still a very good answer.  Thanks.

Answer 4

So the trees might be correct just slim chances of matching? That makes me feel a little better. I was stressing this morning about where I might have made a mistake, lol. He has a pretty good trail for me to follow.

Thank you everyone for helping!