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Archiver > GENEALOGY-DNA > 2007-04 > 1175442512


From: "Lawrence Mayka" <>
Subject: Re: [DNA] Average Mutation Rate/Generation vs. AverageMutationRate/Transmission
Date: Sun, 1 Apr 2007 10:48:32 -0500
In-Reply-To: <bf7.131e5241.33412600@aol.com>


My opinion on this:

Pedigree mutation rates actually work rather well, and coincide with other
evidence rather well, if _both_ are properly interpreted.

1) Applying the pedigree mutation rate to a large population (such as a
subhaplogroup) without significant substructure can give you a reasonable
time estimate since the population's most recent rapid expansion (MRRE).
This typically will be more recent than the population's origin. The
interval between origin and MRRE is not generally knowable from haplotype
diversity and mutation rates--it must be calculated by other means. Ken
Nordtvedt's approach, of constructing a tree of founder haplotypes, seems to
be a promising one in the short term. In the long term, if we can
cost-effectively sequence large segments (i.e., unbiased large samples) of
the Y chromosome, we can estimate haplogroup ages by counting SNPs.

2) Non-DNA evidence must be interpreted according to an interdisciplinary,
strictly factual (not political-emotional) approach that does not skew
conclusions in order to please one's colleagues or powerful lobbies, or to
fit one's own political-social views. Nor should we ever forget a
fundamental principle of scientific inquiry: Lack of evidence is not a
proof but a challenge.

> [mailto:] On Behalf Of
>
> However, using more realistic values for mutation rates for
> these types of
> calculations generally result in estimates which are much too
> low and don't agree with other non-DNA sources.


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