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

Len Piotrowski (
Wed, 4 Sep 1996 14:13:46 GMT

In article <50528n$> (Bryant) writes:

>>This is all well and good, but as I've made clear, the problem that arose was
>>with your "sugar craving" and "jealousy" traits as apparent counter examples.

>I thought that I pulled those from my hat to illustrate (crudely) how
>once-adaptive traits need not be currently adaptive. I think I was
>critiquing problems with optimality models (something Gould and I agree
>about), not attacking Gould.

Whatever your reason, and however crudely you presented it, the
functional adaptationist explanation of your behavioral examples are still

>I could be mistaken, but I thought that you pulled the various quotes
>from different msgs and put them together to show that I was being
>inconsistent by saying Gould overstates his case and then daring to
>speculate about the adaptive function of sugar craving and sexual jealousy.

You are mistaken. I could provide your original post, but what difference
would that make?

>>Then I guess you would agree that there are other possible processes
>>accountable for the existence of these "traits."

>Of course. How many times must I say I'm not Dr. Pangloss before you'll
>believe me?!

As far as I am aware, this is the first time you've admitted to possible
non-adaptationist origins for "sugar craving" and "jealousy," at least in this
thread. Did I miss something along the way?

>>These were juxtaposed in context with the Gould & Lewontin critique, not,
>>interestingly, as examples of "functional design," but as an apparent counter
>>to Gould & Lewontin's claim. I merely pointed out that they *were* examples of
>>"functional design," something to which you took some exception.

>I think I just communicated poorly. And perhaps misunderstood your point.
>I think that the adaptationist program is sensible; look for a functional
>"purpose" for a trait before dismissing it as the result of non-selective
>forces of evolution. It's easier, usually, to test the predictions
>derived from adaptationist hypotheses than from hypotheses which posit
>that a trait has no functional significance.

This is still incongruous given your critique of Gould & Lewontin. Despite this
poor communication, I would submit that the method you choose to "look for a
functional "purpose" for a trait" creates only the illusion of an explanation
because it posits a priori a need that is outside the system of analysis and
patently unclassifiable as a "trait."