Bill, I have further questions: Let us assume that two brothers are born, one of whom carries the mutation SNP M222 at his conception, the other remains ancestral (we'll call him L21). Each has a chain of male descendants, a representative from each chain being born in the 20th Century, and tested by FTDNA. Their results (because they have fairly stable YDNA) come out as, say two, or three, or six GD one from the other, so far as haplotype is concerned. Question: What time would your methodology give for the TMRCA? Would you not think that the age of the haplogroup is a consideration? Regards David On 11/07/2011 8:25 AM, Bill Howard wrote: > Paul, > If the two haplotype strings are statistically the same, I don't really care. They lead to the same dates. > I agree, we are now beating on a dead horse. > I am sorry you think I am tiresome but you don't appear to understand that the date of origin depends only on the haplotypes presented to the program, not whether or not it is a member of a particular SNP. > (In the two postings immediately below, I find that only you used the word "unknown")….. > - Bye from Bill Howard > > On Jul 10, 2011, at 6:11 PM, Paul Conroy wrote: >