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From: "David Ewing" <>
Subject: Re: [DNA] OK, you Mathematical Mutation Masters
Date: Tue, 23 Sep 2008 06:22:37 -0600


Bill Hancock writes: "When was the MRCA for two persons of the same surname
and in the same deep clade (haplogroup, if you will) in one of the ultimate
strings in the R1b1 series of haplogroups, when they differ by 22 genetic
distances in 67?"

I have no idea what "ultimate strings in the R1b1 series of haplogroups"
means. The definition of R1b1b2e is M222+, but this characterizes
approximately the same group as those within about genetic distance 10-12 of
the R1b1b2e STR 67-marker modal. I think it is highly unlikely that two men
that have sub-clade STR specification to the level of the sixth figure after
the R (is that an "ultimate string?") would differ by genetic distance
22/67, though I suppose that is not impossible. On the other hand, I think
it might be quite common to find this much difference between men who are
R1b1b2* and it certainly would be between men who are R1b1*.

I believe that you can safely conclude that two men who are at genetic
distance 22/67 will have the same surname only by coincidence. Their TMRCA
will be approximately the same as that of all the haplogroup R men in the
British Isles. Our experience has been that men related within a genealogic
time-frame will have genetic distances of no more than four or five from
their own modal, and less (usually much less) than seven or eight from one
another.

David Ewing

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