Re: Peppered moths again

Mark D. Kluge (
Wed, 31 Mar 1999 17:02:09 -0500

Brian D Harper wrote:

> Aren't you just re-inforcing Wells' point by insisting that the
> explanation for the "increased reproductive success" involves a
> Darwinian mechanism while admitting at the same time that such
> mechanism is "perhaps unknown".

Wells doesn't have a point. Here the Darwinian mechanism is tautological. What is
(or was) observed is changing differential reproduction rates between familiar and
carbonaria peppered moths. What causes such changes? The most general and skeptical
answer is that something in their environment changes, resulting in, for some
reason, known or unknown, increased ability of organisms exhibiting one of a
heritable trait at the expense of organisms exhibiting another heritable trait. Such
processes are called "selection", which is the Darwinian mechanism.

That some selection process is involved is not disputed by anyone, nor can it be. Of
course one does need to seek the mechanism(s) underlying the observed selection.
Otherwise, as I have noted, the whole thing here is tautological. But the rational
debate centers upon identifying what was responsible for selection, not on whether
selection happened. One can argue over how the Darwinian paradigm applies to this
situation. One might even argue over whether the Darwinian paradigm offers the best
understanding of this situation. One is free to apply whatever sound paradigms one
wishes, I suppose. However, because it follows so trivially that the Darwinian
paradigm can be applied, Wells' objection is not well-stated.