Re: My last word
Wed, 21 Apr 1999 17:21:12 EDT

In a message dated 4/21/99 12:02:52 PM Mountain Daylight Time, writes:

> >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.
> >
> How nice for you. I have no expertise in industrial melanism,
> biological field work etc. I do know something, however, about
> experimental methods. Nothing Wells has said in this regard
> strikes me as foolish. In fact, quite the opposite.

Then I guess you haven't been paying attention to what Don Frack has been

> BTW, I take it you are an expert in this field?

Majerus is, and Don Frack is the closest thing we have to an expert in this
group itself. Both are saying the same thing I am; in fact, I am simply
reaffirming their own conclusions. If Wells believed that he had a
legitimate critique, as a scientist he should have submitted a letter or a
short paper to a peer reviewed journal so that the experts on the peppered
moth could examine it. If they agreed with him, they would have said so; if
however he was mistaken they would explain how. It would then be up to Wells
whether he accepted their expert opinion or not, but most scientists in his
place would be relieved to discover they were wrong.

Instead Wells went public with accusations of fraud, for political purposes
rather than scientific ones. And when the experts explained to him that he
was wrong and how, he rejected their explainations on the grounds that they
were simply blinded by Darwinian bias. His claims were legitimate until they
were shown to be wrong; now they are simply rhetoric meant to try to create a
problem where none exists. It's obvious, both to me and to others, that
Wells is not interested in correcting science or his own opinion; rather he
seeks an issue he can use to try to convince lay people and school
administrators and textbook publishers that evolution is false. That he is
promoting an issue he knows is false is what makes him foolish.

> [skipping some]
> BH:===
> >>
> >> 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.
> >>
> >
> KO:===
> >If you did not already know that the moths were resting on tree trunks,
> >could you distinguish that from say a large diameter bough? The point is
> >still, though, that the PLACE mattered little, only the color contrast.
> >
> Interesting. Below you give differences in hunting styles which
> show that the place does matter. Of course, this would matter
> little wrt the central claim that bird predation is the cause
> for the differential success of the two colorations. Nevertheless,
> it is an indication that place *might* matter.

Look again at what I said: I said the place matters little, I didn't say it
didn't matter at all. By the way, the differences in hunting styles do not
increase the probability that place would matter. Pattern recognition
predators can still be fooled by camouflage; the classical experiments and
the more recent follow-up experiments demonstrated that when the moths did
rest on trunks that pattern recognition predators still preferentially took
moths whose color had the highest contrast with the background. As such,
since camouflage is even more effective against movement/color contrast
predators, you would expect the preferential predation would be even stronger
in the canopy.

> Has anyone demonstrated
> empirically that selective predation occurs where moths normally
> rest?

According to Majerus, yes; the details and references are in his book.

> As another possible influence of location, would you happen to
> know off hand whether lichens grow better on tree trunks as opposed
> to branches?

It depends upon the species, but generally no.

> The brief quote I gave from Futuyma indicated that viability
> of the two forms differs even in the absence of predation.
> This suggests to me that it might be important to figure
> out what the mechanism for this is (perhaps someone already
> has) and then to check whether air pollution might have some
> effect on this mechanism.

You have a later edition than I do. Again, however, this simply indicates
that the scenario is not as simple as textbooks or Wells make it out to be.
And there is still no evidence that pollution has any effect on gene
frequency in any form. Until there is, this simply remains speculative, and
it still does not refute the results showing that preferential predation is
the main cause of the phenotypic shift.

> >>
> >> 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
> >(or the standard high school textbook description) make it out to be.
> >However, there are bird species -- nuthatches, titmouses, chickadees,
> >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
> >the wing" so to speak, and while they would be closer to their prey, a
> >camouflaged moth that remains still would be overlooked, whereas one
> >body color was a sharp contrast to the background would be attacked even
> >it did not move. These small "creeper" birds hunt by movement and color
> >contrast, not by pattern recognition.
> >
> Which brings me back to one of my questions above. Is there
> empirical evidence for differential predation in an environment
> such as you describe above?

Again, according to Majerus there is, and the details are in his book.

> Please accept my humblest apologies if I am acting overly
> foolish :).

For someone who criticizes others for discourtesy in their writings, you can
be very sarcastic when you want to be. You at least have an open mind and
want to learn the truth. Wells was never interested in learning the truth,
but in gaining a weapon he could use against materialism and dogmatic

Kevin L. O'Brien