My brother and I have both had Y testing performed through FTDNA.

Based on the distributions within the "Recent Ancestral Origins" (i.e., RAO) page of my own profile, I think our folks come way back from central Scotland. I have 6 near-matches at 25 loci from Scotland vs. 1 from England.

Based on my paper trail, my strongest suspect for this non-paternity event was surnamed 'Cameron'--way Scots. I've been mistaken before, so I say 'strongest suspect' to mean 'strongest suspect at the current moment'.

My brother's results sorta match a Cameron 'modal' value I calculated with the Ydna compare tool available online. I say 'sorta' match because while he's a 100% match through the first 17 loci, it falls off after that. Total G.D. of 9 over 37 places, but no more than 1 count off at any place after the first 17.

I'm only G.D. of 1 vs. my brother. Mutation or count error? I don't know, and I don't consider it too significant--except as regards the 'tolerable' deviation for interpreting the results versus some other folks named Cameron.

Is a G.D. of 9 vs. a Cameron modal just too far off to be suggestive?

Published histories make it clear that a large number of totally un-related persons adopted the surname in an attempt to curry favor with a powerful landlord. So I am dubious about reading too much into such a 'modal' value.

Only 13 FTDNA customers named Cameron have tested beyond 12 loci. So, sample size may be an issue for the validity of my 'modal'.

But the possibility that there may be an accumulation of individually insignificant count 'errors' among these samples may mean that these Camerons are more closely related than I think.

So, what do you think?