Sandy, I don't know much about mutation rates, which I thought were random. That "Dubhthach" chart I sent the list shows many mutations downstream of L21 that do not seem to have mutated at all, some that have mutated once more, and one (L625)that is seven steps away from L21. Obviously, we have much yet to discover. What I was trying to say (but upon rereading my message I see I did not do well) was that testing DF23 will help determine the origins--geographical and in time--of M222. Being upstream from M222, DF23 must have divided into those who are DF23+ and M222+, and those who are DF23+ but M222-. If a focal point of the latter is determined, that MAY (stress the "may")be where the M222 mutation occurred. Paul