The just-so-ish nature of almost all evolutionary explanation has been frequently noted. It is a staple of creationist objections to evolution. The fact is that we will never do a lot better than the sort of explanation I offer here for most traits. We can only guess why they were adaptive, if they were. We cannot test the adaptiveness of those traits in a Morgan fly lab. Historical evolution was a one time event with no scientifically set up control group, no second chances, and most of the evidence is lost. Almost all of it.
That leaves us with (a) the knowledge that evolution by natural selection is the only way to account for the origin of species and the existence and persistence of biological traits, (b) the knowledge that most such traits that survived must have increased adaptive fitness at some point -- this is a corollary of (a); (c) ignorance of specific mechanism of adaptiveness or the particular evolutionary stories about why any particular trait (in the case of most traits) increased adaptive fitness, (d) knowledge that some such just-so-story as I tell, if not this then another one, must be true to explain the emergence, variety, and persistence of biological traits.
Look, this biology 101 and baby philosophy of science.
In Abusing Science Phil Kitcher explains in more but not excessive detail why the pseudo-Popperian objections to evolution (and your objection here cannot be distinguished from general pseudo-Popperian objections to evolutionary explanation in general) are bad science and bad philosophy of science.
I suppose I shall have to keep repeating this.
--- Michael Smith <mjs at smithbowen.net> wrote:
> On Tuesday 23 January 2007 13:32, andie
> nachgeborenen wrote:
> > ... the placement of
> > the clitoris, inconvenient for bringing the woman
> to
> > orgasm through intercourse, and promoting
> intercourse
> > would seem to be a major adaptive value of orgasm,
> > because it gives women an opportunity to assess
> > whether whatever partner she's engaging in sex
> with --
> > and this may be one or many -- would go the extra
> > mile, as it were, to satisfy her sexual needs
> rather
> > than merely selfishly indulging his own. This
> would
> > give her information about whether he might be a
> good
> > mate ...
>
> Lotta subjunctives here. Not to be Popperian or
> anything,
> but isn't there something unsatisfactory about a way
> of thinking
> that requires hypothesis piled upon hypothesis, and
> offers
> no way to confirm or refute any of them?
>
> It would be easy enough to come up with any number
> of
> such explanations for the perverse placement of the
> clitoris,
> or any other vexatious trait. A quick troll through
> Google
> suggests that one popular, competing sociobiological
>
> explanation for the shy little pearl's
> out-of-the-way domicile
> is that it encourages women to select sexual
> partners with
> large penes. I do not have the privilege of
> possessing a clitoris
> myself, but perhaps some of our clitoridiferous
> fellow-listers
> can comment on whether well-endowed partners do or
> do
> not create more clitoral bliss, just as a physical
> side-effect
> of megalophally.
>
> A cynical reader might speculate that Andie thinks
> nature
> selects for Alan Alda because of an ideological
> commitment
> to Aldatude; other sociobiological tale-spinners may
> have
> ideological commitments that lead them to emphasize
> hammer-tude. How to decide?
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