GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2005-01 > 1105579954
From: (John Chandler)
Subject: Re: [DNA] Male Line Specific Y-STR Average Mutation Rates -- theone size shoe/(haplotype mutation rate) fits all approach is not valid,imo -- corrected URL link
Date: Wed, 12 Jan 2005 20:32:44 -0500 (EST)
References: <014701c4f8f6$26e5e3a0$6401a8c0@whit> <41E5AE07.email@example.com>
In-Reply-To: <41E5AE07.firstname.lastname@example.org> (message from Charles on Wed, 12Jan 2005 18:08:55 -0500)
> Some family lines having a consistently higher
> rate than others. Some having a consistently lower rate.
This is the heart of the matter. What, exactly, do you mean by
"consistent"? Take the first two panels together of the Kerchner data
as an example. With a measured average mutation rate of 0.0047, a
"consistent" performance would be 0.0047 mutation at each opportunity,
or 0.1175 mutation per transmission event.
Instead, what we see is 846 opportunities with no mutation at all and
4 with one each. Absolutely every event was different from the
expectation. Since two of those mutations showed up shared by the
same two testees, it is quite possible that both mutations occurred in
the same man, a common ancestor of theirs, because that man happened
to carry around a "lucky stone" made of pitchblende, or was a heavy
tobacco user. Both of the other two mutations were "surprising" in
the sense that they were 0.9953 away from the expected number. The
outcome is clearly dominated by a small number of highly improbable
events. Another way of saying it is: this result was entirely an
accident and could easily have come out quite differently. This is
why it is so important to calculate the statistical uncertainty along
with the average rate.
So far, I have not heard of *any* family with a rate that was
*significantly* higher or lower than average. *All* of the reports of
really extreme mutation rates have come from modest-sized projects
with correspondingly large uncertainties. Larger projects come closer
to the average (as expected).
|Re: [DNA] Male Line Specific Y-STR Average Mutation Rates -- theone size shoe/(haplotype mutation rate) fits all approach is not valid,imo -- corrected URL link by (John Chandler)|