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Archiver > GENEALOGY-DNA > 2007-07 > 1183946449


From: "Joe Knapp" <>
Subject: Re: [DNA] Help please with marker 458
Date: Sun, 8 Jul 2007 22:00:49 -0400
References: <008701c7b415$794b0120$2401a8c0@your447023ae6b><REME20070703220030@alum.mit.edu><a81622ac0707041809y68277e45iaa87951637aacb9a@mail.gmail.com><REME20070705181857@alum.mit.edu><a81622ac0707051724y16754956obfb853b6686e74ed@mail.gmail.com><REME20070707152459@alum.mit.edu><a81622ac0707071304x11373a0en3b0b4e52a7b2e3c@mail.gmail.com><REME20070707183721@alum.mit.edu><a81622ac0707071637o34a3421dr36660529da9f75a4@mail.gmail.com><REME20070708181915@alum.mit.edu>
In-Reply-To: <REME20070708181915@alum.mit.edu>


On 7/8/07, John Chandler <> wrote:
> Joe wrote:
> > I think you are getting stuck on the reductionist sexual aspects of
> > interbreeding, as opposed to more general population effects. Fact is,
> > if tribes interbreed with one another it will greatly affect the
> > haplotype distributions compared to if they don't.
>
> Fact is, the geographic distribution of haplotypes is of no interest
> here. Your final product is a simple, effectively unordered list of
> all haplotypes in the end population, taking all tribes as one pool.
> It doesn't matter whether the male-line descendants of one man are
> concentrated in one tribe or are scattered throughout the planet.

Just try it, you'll see a big difference in the case of one tribe of
10,000 vs. ten non-interbreeding tribes of 1,000. According to your
position, it shouldn't matter--but it does, and it's straightforward
to see why: decoupled tribes drift apart.

> What *does* matter is the imposition of a constant size on each
> tribe.

Sure, and a population of 1,000 will exhibit genetic drift more than
one of 10,000.

> > I'm not sure what you mean by oscillation--something I could measure?
>
> You could take the Fourier transform of the number of offspring taken
> as a function of the father's date of birth.

OK, here's the avg number of offspring per male that has at least one
offspring (many die before having any):

http://coolohio.com/dna/avgoff.jpg

There's a high birth rate at first while the population ramps up to
the preset limit, & then it levels off (modulo statistical noise).

Here's the fft of same:

http://coolohio.com/dna/avgoff.jpg

Joe

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