I agree with John. Of course we cannot pin it down precisely; but with a good sampling of living men, we can not, and should not, resist trying to determine a range. Jim - www.segmentology.org > On Oct 11, 2015, at 1:55 PM, AJ Marsh via <genealogy-dna@rootsweb.com> wrote: > > Orin, > > Yes estimating time to Y Adam is fraught with difficulties, but isn't it just "human nature" to try to do so. Perhaps it is our curiosity to know the seemingly unknowable which makes us human. Long may we play the game of estimating time to Y Adam. > > John. > > Sent from my iPad > >> On 12/10/2015, at 5:23 am, Orin Wells via <genealogy-dna@rootsweb.com> wrote: >> >> There is a major problem with all of this "scientific" computation to >> estimate the earliest ancestor. That is the computed frequency of >> mutation on the various markers. I suggest, and maybe I am completely >> wrong, that the frequency is just an estimation based on the observable >> mutations currently. When I can identify men who have a MRCA who lived >> 400 and 500 years ago who are clearly identified by genealogical records >> and they have absolutely no mutations between them I really have to >> question the accuracy of trying to pin down a common ancestor for all of >> us so precisely.