> Thanks for your considerate reply. It was exactly the kind of
> response I was hoping for. My post was not intended to be an
> endorsement of Wells but rather it was kind of a knee jerk
> reaction against the approach to debate that seems to be favored
> by some. Wells made some specific allegations that can be dealt
> with specifically. Instead, some seem to want to take the track
> that Wells has no right to raise these objections since his
> robes are not long enough and his hood is of the wrong color.
> This I find enormously irritating and contrary to the spirit of
> science.
>
To my knowledge, no one said that Wells did not have the RIGHT to raise
objections. What we were saying is that his lack of knowledge of the
peppered moth and his lack of experience in biological field work (and
apparantly in scientific research in general), not to mention his more
political ambitions, has led him to make foolish accussations that he cannot
support, yet stubbornly clings to even after more knowledgeable and
experienced people have explained how and why he is wrong. We do not object
to Wells because he has the wrong credentials; we object to Wells because he
is a fool.
>
> One thing I've tried to do in the past few years is to see if
> some particular controversial event or practice in evolutionary
> biology or teaching of same also occurs in other fields. This is
> in an attempt to ward off suspicions that certain things happen in
> evolutionary biology because of metaphysical prejudices etc.
> This particular incident reminded me of something I read in
> Richard Feynman's biography. It seems that he had volunteered to
> review physics textbooks for local schools and immediately became
> enormously frustrated by the task. For one thing, it appeared to
> him that he was probably the only reviewer who actually read the
> books :). More to the point, he found really significant and
> fundamental mistakes in these books. I would be inclined to
> think, then, that if such is possible in elementary physics,
> surely biology would not be immune.
>
Thanks for the vignette. Stephen Jay Gould has shown much the same thing.
My own example is that, even up until recently, the popular myth regarding
Columbus was that his voyage was an experiment to prove that the earth was
round. I remember being taught this in grade school. Yet the truth is that
Columbus and in fact most people of his time already knew that the earth was
round. Instead, he used that to claim that it would be easier to get to the
Orient by sailing west instead of taking the far longer (or so he thought)
route east. His mistake was to assume that the earth was smaller than it
really was.
>
> What occurred to me originally was that a photograph of a moth
> sitting on an exposed tree trunk will reinforce not only the
> idea of increased visibility due to coloration but also increased
> visibility due to being out in the open on an exposed tree trunk.
>
If you did not already know that the moths were resting on tree trunks, how
could you distinguish that from say a large diameter bough? The point is
still, though, that the PLACE mattered little, only the color contrast.
>
> Perhaps I'm feeble minded, but being in an exposed position
> seems to accentuate the importance of coloration and to accentuate
> the hypothesis that such coloration affects bird predation. One gets
> a ready minds eye picture of how easy it would be for a bird to
> swoop in and nail that sitting duck :).
>
That's part of the reason why the situation is more complicated than Wells
(or the standard high school textbook description) make it out to be.
However, there are bird species -- nuthatches, titmouses, chickadees, small
woodpeckers and the like -- who actually hunt insects by crawling around the
upper trunks and smaller branches up inside the canopy. As such, these birds
would be the most likely predators rather than say blue jays that hunt "on
the wing" so to speak, and while they would be closer to their prey, a well
camouflaged moth that remains still would be overlooked, whereas one whose
body color was a sharp contrast to the background would be attacked even if
it did not move. These small "creeper" birds hunt by movement and color
contrast, not by pattern recognition.
Kevin L. O'Brien