Fast Mutation versus Slow Mutations

[wmccown]

My cousin, Sam, and I are exact matches at 12 and 25 markers but are one off at 37 markers. The marker in question is DYS 442 where Sam has a value of 13 and I have a value of 12. Trinity College did a 37 marker study of the Y-DNA of the Maguire related families(Maguire, MacMahon, MacManus and MacAuley)and the only family with a value of 13 on DYS 442 is MacAuley. All of the men in the study could trace their lineage to Donn Carrach Maguire, the first Maguire prince of Fermanagh. The study reconstructed the "DNA" of Donn Carrach Maguire from this study along with a "ruling line" and a Maguire modal. The matrix shows the results of each of the above families by marker.
My question is, is this mutation on DYS 442 likely to be usefull in genealogical research of our family line?

[Jim Barrett]

You need to know the value of DYS442 of your ancestral line. Did your common ancestor have a value of 12, like most of those in the study, or did he have a value of 13. The only way to find out is to test more cousins. Is Sam a first cousin or more distantly removed? You need to test other cousins that are at least that distance removed or more. I'd try to go at least one generation on back.

If you paternal line had 12 then it would be of much help. If they had 13 it might.

I don't think this has much to do with fast or slow mutations. Two brothers or a father and his son could differ on the marker with the slowest mutation rate. It has to change some time.

[wmccown]

Fast Mutation versus Slow Mutations

Hi Jim,
Thanks for your questions, thoughts and corrections. I only have one known male cousin and he is descended from a younger brother of my great grand father. We have been unable to find another descendant who can be tested. Also, I realize that mutations are accidents that can happen during any conception. The matrix I have of the Trinity College study shows that only one of the two MacAuley lines has this value of 13 on DYS 442. I was hoping to find out more about our family line via the mutation.
Obviously, I don't know if it is a "tandem repeat" that would tie us to MacAuley and then all the way back to Donn Carrach Maguire in 1301AD or not. Neither Donn Carrach Maguire's reverse engineered DNA nor any other Maguire line has a value of 13 on that marker. We may have to get an opinion from FTDNA.

[wmccown]

Fast Mutation versus Slow Mutations

Darren at FTDNA responded to my email saying that DYS 442 was a slow mutating marker and thought that it was a within just a few generations that it occurred. Four generations have occurred since my GGGF and it was found in the line of GGGF's second son.

He further said that the other mutations within our line supported FTDNA's conclusion. In short,it does have a MacAuley connection but not as a fast or tandem repeat. So, as far as I am concerned the purpose of this thread has been satisfied.