Re: Natural Selection (was: Breast Size)
Gerold Firl (geroldf@sdd.hp.com)
14 Jun 1995 17:45:34 -0700
In article <3rniu4$knf@tardis.trl.OZ.AU> jbm@newsserver.trl.oz.au (Jacques Guy) writes:
<A bunch of stuff which seems to be intended to insist on scientific rigor
in the description of evolutionary processes, but which is in such a
confused state as to be useless for quotation.>
I think everyone agrees that evolutionary processes do not have any "look
ahead" ability; selection can only operate on attributes which provide
either immediate advantages or disadvantages. Fine. Nonetheless, for
descriptive purposes, it often makes perfect sense to describe the reason
for which the trait was selected.
For instance, we can say that the long neck of the giraffe evolved to allow
the animal to feed on leaves which were high off the ground. Agreed? Taking
a committment to semantic purity to such an extreme as to disallow such a
statement is excessive.
The body shape of the dolphin evolved to minimize hydrodynamic drag, and
maximize propulsion efficiency. This does not imply any kind of lamarkian
process, teleology, or mystic destiny as any part of evolution. When a
strong selection pressure exists, it "pushes" the direction of evolution in
a very obvious way. Generally, when a particular trait is described
(somewhat metaphorically, to be sure) as having evolved "to" provide some
particular function, this should be interpreted as a statement that the
trait, whether morphological or behavioral, developed as the result of a
particular selection pressure. That's all.
--
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=-=-=-=-=-=-=-=-=-=-=-=-=-=---- Gerold Firl @ ..hplabs!hp-sdd!geroldf
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