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Archiver > GENEALOGY-DNA > 2007-02 > 1171588090
From: (John Chandler)
Subject: Re: [DNA] TMRCA
Date: Thu, 15 Feb 2007 20:08:10 -0500 (EST)
References: <200702152136.l1FLadHQ023698@mail.rootsweb.com>
In-Reply-To: <200702152136.l1FLadHQ023698@mail.rootsweb.com>(restes@comcast.net)
Roberta wrote:
> The Estes surname project is significantly larger than this, but when I
> prepared this chart, I used only proven genealogies, not ones where I know
> they connect but exactly how is "fuzzy", because I needed to know the number
> of transmission events that had occurred.
More on this in a moment...
> On the page labeled 458...
> You get the idea. So there are 3 mutations of a combined number of mutation
> opportunities of 160, for 2%.
Ok, carrying this to an extra decimal place, that's 0.019, and the
statistical uncertainty is sqrt(3)/160 = 0.011. Now, compare this
with the estimated rate of 0.008 +/- 0.001 from my JOGG paper.
You'll see that your rate estimate is consistent with mine to within
the uncertainties.
> For marker 391, Abraham Sr. is 12, and you can see there are 8 mutations out
> of 160 possible events, all downward mutations.
>
> The interesting thing for both of these mutations is how many individual
> lines they occurred in independently.
>
> I surely have to wonder why these alleles are "predisposed" (or maybe
> "inclined" for lack of another word) to mutation downward, in the case of
> 391.
To me, this slide looks like evidence of *one* mutation in a son of
Abraham, plus a massive confusion over the parentage of Abraham's
grandchildren. I know that is an unpalatable suggestion, but it
is the simplest explanation of your chart. Another possibility,
which you may have already explored, is that your Estes allele
is really 11.2 (i.e., exactly halfway between 11 and 12), and the
rounding off to the "nearest" whole number gave mixed results.
If you haven't asked Bennett about this possibility, you should.
If the parentage of the grandchildren is documented by explicit,
contemporary birth or baptism records, then the confusion idea
probably won't fly, and that would leave the roundoff ambiguity
as the next simplest explanation.
John Chandler
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