Re: about what evolves

Dave Rindos (arkeo4@UNIWA.UWA.EDU.AU)
Sun, 15 May 1994 14:39:51 +0800

On Sun, 15 May 1994, Daniel A. Foss wrote:

> Frankly, from what I've read, I'm not sure *what* evolves, since whatever
> happens consists of certain alleles rather than others becoming more numerous
> within a population; so that over a sufficiently long period of elapsed time,
> it would become a population of something slightly else.

Well....sorta...but not really.... (this kind of stuff is for a class,
not a list). The important thing to remember is that change in alleles
(etc) is an EFFECT of evolutionary process NOT a *cause.* Genes,
alleles, traits, &c &c &c are theoretical concepts with rather specific
domains of applicablity. They don't really exist in a nice neat way.

> Or, it is entirely
> possible for a great deal of selection to go on without much evolution. This
> may be the more usual thing. Then, say the "punctuated equilibrium" people,
> you get an awful lot of evolution in a much shorter time than was going on
> during the slack season.

PE (as opposed to PC, though it was for a while) doesn't seem to be
getting all that much attention anymore. I always was of the opinion that
it was a bit of a tempest in a teaspoon in any case. Basically it was an
attempt to show that allopatric speciation would yield the same sorts of
patterns in the palaentological record as we generally find. The
*relative* importance of phyletic/ gradualist processes seems still under
discussion, but their existance seems to be unquestioned. This is all
somewhat tangential to discussion of cultural selection in any case since
the aims of PE were directed to speciation problems, not those of
intraspecific variation. Isolation, however, is and will remain an
important area for research if for no other reason that fitness is
undefined unless interaction occurs.

> The hairsplitting over "fitness," "inclusive fitness," "adaptation, is it
> or isn't it" has got some biologists confused, so why not me too.

I think it's much nicer to call it "productive debate regarding fundamental
concepts" :{)

> Suppose that
> humans grew bigger and better brains than they really needed to in order to
> become Top Species. Why, then, should they have evolved those brains as big
> and high quality as they did?

Funny that.

We had those Big High Quality Top'a'the'ole'evolutionary'ladder Brains
(TM) for a heck of a long time. Good old palaeolithic kept a dragging on,
and on, and on . . .

On which (Big Brains, that is), Wallace had a big falling out with Chas
Darwin over this same issue. Couldn't see how natural selection could
have done it. Me, I'm not overly impressed, but then again I probably
watch the evening news too often. Not quite sure what Darwin said.
Probably nothing. Which would be the smartest reply, I guess.

Dave

--

        Dave Rindos               arkeo4@uniwa.uwa.edu.au

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      [you may also reach me on rindos@perth.dialix.oz.au]

 

        >Suppose they gave a culture and nobody came<