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Archiver > GENEALOGY-DNA > 2005-05 > 1115225460


From: Doug McDonald <>
Subject: Re: [DNA]SNP and STR mutation rates
Date: Wed, 04 May 2005 11:51:00 -0500
References: <1db.3b0d904d.2faa3fbe@aol.com> <0d6b692bf63ff48b566b5eb527da496d@earthlink.net> <003f01c550c6$cd318b10$c6559045@Ken1>
In-Reply-To: <003f01c550c6$cd318b10$c6559045@Ken1>


Ken Nordtvedt wrote:

> Let's go back to the beginning. Assuming there are 25 million places in
> each male's non-recombining ydna where he could have a SNP mutation, and the
> probability of such a mutation at each site was on average about 1 in 50
> million per generational transition, then every ancestral line on earth
> would have a mutation about every second generation averaged out into the
> past. .... If we had a database of all the mutations in
> a large enough sample of the population, we could arrange them in a tree
> branching out from Adam to the present.
>

You might be able to get a tree, but you might not be able
to generate an actual tree, rather you might
be stuck with a network, with cycles. With there having been
about 3 billion men around, there is lots of room for recurrent
mutations at each site. OF course, this is reduced
dramatically since five generations ago the total
number of men who had ever lived was far far less.

Doug McDonald


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