Yes, you're right of course. But they are hardly species-creating changes. I
should have been clearer: I was talking about macro-evolution (going way
back to prebiotic), not improvements within a species.
If you take the changes necessary to take a mouse's genotype to a human's,
how many of those changes are individually beneficial?
James
----- Original Message -----
From: "Antoun Nabhan" <antoun@incellico.com>
To: "James Tauber" <jtauber@jtauber.com>; "FoRK" <fork@xent.com>
Sent: Friday, April 20, 2001 7:23 PM
Subject: Re: Evolution being slow ...
> At 06:36 PM 4/20/01 -0400, James Tauber wrote:
> >One thing that has always fascinated me is the number of genotypic
mutations
> >that need to take place for the phenotype to have a beneficial change.
It's
> >not as if a single change to the DNA has an immediate benefit. You really
>
> Huhwhat? There are Single Nucleotide Polymorphisms - one-base changes -
> that account for significant phenotypic mutations like Huntington's
Disease
> and increased resistance to certain cancers. Likewise, a change in a
> limited number - frequently 13 or fewer bases appear to account for
> differences in "Continuum Traits" like blood pressure and ability to
> metabolize cholesterol. So maybe there's a big probabilitistic
> concatenation to get from a mouse to a human, but to get from an early
> human to a healthier, stealthier human isn't necessarily so improbable.
>
> I'm not a bioinformaticist, but I play one at conferences,
> --Antoun
>
>
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