Howard, Until recently, I would agree that 25-marker matches define the branch and 37-markers define the twig. However, I have had two MacLarens match 25/25, but at 37 markers they had 6 markers mismatch. This is too many and indicates any relationship is too far back in time to be genealogical meaningful. I have requested that the results be doublechecked, so if this changes, I will let you know. Based on this, and some others who were in the grey area at 25 markers, I now strongly urge anyone joining my project to get 37 markers. Bob > [Original Message] > From: Howard Wayne Roberts <wayne@connectfree.co.uk> > To: <SCOT-DNA-L@rootsweb.com> > Date: 7/10/2006 9:32:30 PM > Subject: Re: [SCOT-DNA] MacWho and The Bruce > > I don't think thats the case Jim, although I agree that the 12 marker is > not a good indicator other than a distant possibility. > > I am baffled by the fact that some of your Gordon matches at 25 didn't > hold up to the 37 marker resolution, but doesn't that just indicate a > younger/older branch of the Gordon line rather an entirely different > line? The last 12 markers at 37 are known to mutate quickly than any > other. What I meant to say is that if there is some convergence at 25 > markers then surely these Gordons share an ancestor with you be it x > years ago. > > In the Roberts Bahamas project, where it was known that they all shared > a common ancestor 300 years ago. Some of the lines were only 21/25 with > each other, never mind at the higher 37 resolution, and these Roberts' > are not close to anyone else Worldwide. > > Rule of thumb is that the 12 marker is the tree, 25 the branch and 37 > markers the twig. > > Regards > > Howard Wayne Roberts

Hi Robert I tend to agree, but don't forget that this is all cumulative probability. The 31/37 McLarens could possibly be related in genealogical time. I have at least one experience where a test >37 made two people look more similar again. One thing to keep in mind is that the 3rd panel of FT DNA is full of "fast changing" markers. There are also certain types of mutation which can quickly give a big looking distance. For example YCAII can go from 19-23 to 19-19 in one step. But I agree that 25 marker tests often give misleading impressions, and 37 marker tests normally don't. Best Regards Andrew -----Original Message----- From: robert mclaren [mailto:bobmclaren@earthlink.net] Sent: Friday, 14 July 2006 5:13 AM To: SCOT-DNA-L@rootsweb.com Subject: Re: [SCOT-DNA] MacWho and The Bruce Howard, Until recently, I would agree that 25-marker matches define the branch and 37-markers define the twig. However, I have had two MacLarens match 25/25, but at 37 markers they had 6 markers mismatch. This is too many and indicates any relationship is too far back in time to be genealogical meaningful. I have requested that the results be doublechecked, so if this changes, I will let you know. Based on this, and some others who were in the grey area at 25 markers, I now strongly urge anyone joining my project to get 37 markers.