Dear Barton, Multi-step mutations can occur. That could account for the move from 12 to 9. There could have also been a series of single-step mutations or a single-step mutation as well as a two-step mutation. Also consider the possibility of lab error. Testing out to 67 markers can sometimes be helpful in situations like this. Testing a paternal first or 2nd cousin of Curtis' with a 37-marker test could also help pinpoint where the mutations in Curtis' line occurred. However, it would appear that the three Bennetts share a common ancestor who lived within the past 500 to 600 years or so. You might want to consider doing an autosomal test on Ken, Jon and Curtis to see if they share any autosomal segments and also consider testing some of their close relatives to see if any of those close relatives share any autosomal segments with Ken, Jon or Curtis. Sincerely, Tim Janzen -----Original Message----- From: autosomal-dna-bounces@rootsweb.com [mailto:autosomal-dna-bounces@rootsweb.com] On Behalf Of Barton Lewis Sent: Saturday, October 12, 2013 8:06 PM To: autosomal-dna@rootsweb.com Subject: [AUTOSOMAL-DNA] Y-DNA Question My Bennett cousins (Jon and Curtis) appear to be descended from brothers, based on strong circumstantial evidence, both born around 1810. They mismatch on 2 markers out of 37, 1 step on DYS460 (11 v. 12) and 3 steps on DYS442 (9 vs. 12). Curtis's value of 9 here is the only one for the entire group of 11 men that is not a 12. Another man, Ken, is a prefect match with Jon. But Ken, though not without paper trail evidence to a common ancestor a few generations back, does not seem so closely allied with Jon as is Curtis. If Jon and Curtis share a closer common ancestor, could their mutations have occurred somewhere further down the line? What about the odd value for Curtis at DYS442? Thanks, Barton