Re: Evolution, "adaptation", and what's currently adaptive

Len Piotrowski (lpiotrow@magnus.acs.ohio-state.edu)
Wed, 28 Aug 1996 13:16:30 GMT

In article <3223BEB0.7965@megafauna.com> Stephen Barnard <steve@megafauna.com> writes:

>[snip]

I appreciate the concern and hope I can clarify my position on "adaptationist"
speculations. Let me be clear, I am not "hostile" towards such things. My main
problem with Bryant's original post was the incongruity of his critique of
Gould & Lewontin's claim juxtaposed against his clearly functional
adaptationist examples. I was curious to discover how he rationalized such a
situation in his own mind. I'm still not at all certain how he's convinced
himself there is no problem.

I do not " reject out-of-hand *all* adaptationist arguments." However, there
is a difference between bold assertion based on inference and parsimony and
verifiable evidence based on scientific method. If Bryant can afford me such I
would be more than glad to concede the adaptationist explanation for "sugar
craving" and "jealousy." However, the dialog may still continue, but I have
my doubts about this "solution" to the problem.

I think your last question hinges precisely on the claim that Gould &
Lewontin were making: does every current and future parsed structure and
behavior have to be accounted for by a functional, adaptationist explanation?
If something doesn't have a function or adaptation how do you comprehend it's
coming into being? I may be wrong, but I would think that those in the
biological sciences would feel more comfortable with the former, while those
in the social sciences would include a larger number of the latter thinkers.

If "sugar craving" is functionally adaptive for brain development, what are
the logical implications of this hypothesis? Would you expect, for instance,
higher IQs among those who "craved" sugar the most? Would you expect the
"dullest" in our populations to have reduced effectiveness in their sugar
receptors? Would you recommend that our infants be fed on sugar-water during
their early years of development to enhance brain growth?

If "jealousy" increases fitness, how do you account for competing jealousy
motives between the sexes? How do you quantify the "jealousy" trait across
different populations? How do you identify the "jealousy" effect in
previous populations? How do you justify characterizations of cultural
instances of sharing, cooperation, and the virtual lack of jealousy as
relatively less-fit?

I agree totally with your evaluation of just-so-stories. I'm extremely
cautious when I see them applied to the understanding of human behavior. Yet
my main point of contention with Bryant was not so much the minutiae of this
argument, as the apparent inconsistency between his critique and practice.

Hope this at least gives you a little better idea of where I'm coming from.

Cheers,

--Lenny__