How can this be right?

[jillruss]

Sorry - this is complicated!

I manage my niece's (C's) test results. Today she has a new match with 37 cMs - a reasonably biggie.

I checked for a corresponding match in my own list (7cMs) ; in her uncle's (my brother)(none), and finally in her father's (my brother)(7cMs).

 This new match has a smallish tree but I couldn't see any familiar names, though the locations were  possible. So, I checked for shared matches on C's list and came up with two people who ARE on C's list but, when I checked her full list of matches, they are from her mother's side, which must explain why her number of matched cMs is so much higher than her father's. It seems Ancestry only indicate which side of the family the match is on when you look at the full list - if you just go for the 'new matches' list, it isn't indicated one way or the other.

Neither of those two shared matches with C and the new chap are on my list nor either of my two brothers' lists. So far, so good in that this must be a match from her mother's side. However, why would both myself and C's father (but not the other brother) also have a small match with the new chap? I've checked our shared matches with the new chap and in both cases (me and C's dad) the only shared match is C!!

Does this mean that somewhere along the line our side of the family 'intermingled' with C's mother's side of the family. Or is it more likely just a blip?

[mrcakey]

7cM is a pretty distant relation. It's entirely possible you're a distant cousin of the "new guy" and that your niece is a closer cousin on her mother's side.

On that very point I was at a talk yesterday and a husband and wife revealed that they'd discovered through DNA testing that they were in fact 5th cousins.

[Craclyn]

Your match with this chap could be through a completely different line.

[jillruss]

That must be correct. I don't think I stand a cat in hades chance of finding it without a bigger tree from the mystery match - and he's in Oz!!

I think I'll hold that one in abeyance for the time being!

[Craclyn]

The 37 cM match is probably worth following up, but I would not waste too much time on the 7 cM matches.

[jillruss]

I agree, in principle, but - alas - the 37cM match is from my niece's mother's side. I'm from her father's side, and her mother isn't at all interested in her family history.

I've just made a note of the very small match with myself and her father and will leave it at that for now. If the mystery match's tree miraculously gets bigger, I might have a go!!

I have found a couple of instances when I've revisited some of my matches and the person has either produced a tree when there wasn't one before, or grown their tree so that it has more branches than previously! Always worth revisiting if you have the time.