Yes, I saw the same show. The size of the beaks changed in proportion to
the kind of food that was available. Some beaks were better at breaking
open harder seeds, other a softer stuff, etc. As the weather and seasons
changed, the kinds of seeds would change, and the number of birds with each
kind of beak would change dramatically over just a few generations. There
is also a great book about it called "The Beak of the Finch." --
At 07:34 PM 4/20/2001 -0700, Dave Winer wrote:
>Actually, I hear, under some circumstances, evolution is very fast.
>Someone did a study on the Galapagos with some kind of bird that adapted,
>through evolution, to changing food supply.
>After a few generations, just a few years, they had longer beaks and shorter
>toes, or something like that.
>I saw a PBS special on it some years ago.
>----- Original Message -----
>From: "James Tauber" <email@example.com>
>To: "FoRK" <firstname.lastname@example.org>; "Antoun Nabhan" <email@example.com>
>Sent: Friday, April 20, 2001 6:16 PM
>Subject: Re: Evolution being slow ...
> > Yes, you're right of course. But they are hardly species-creating changes.
> > 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" <firstname.lastname@example.org>
> > To: "James Tauber" <email@example.com>; "FoRK" <firstname.lastname@example.org>
> > 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
> > >
> > > 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
> > >
> > >
This archive was generated by hypermail 2b29 : Sun Apr 29 2001 - 20:26:02 PDT