Re: Peppered Moths - in black and white

David J. Tyler (
Thu, 1 Apr 1999 12:41:46 GMT

On Tue, 30 Mar 1999, Kevin O'Brien wrote:

> Lately, in my debates with David Tyler over this issue, I have accepted the
> creationist evaluation of the peppered moth scenario without much objection
> (what I objected to was the further claim that the peppered moth was no
> longer a legitimate example of either evolution or natural selection).

Delays in responding are entirely due to a heavy programme of
conferences and meetings with lots of travelling. I cannot hope to
respond to everything that has been written on this over the past two
weeks. The first thing I would like to say is that I do not see this
as a "creationist evaluation" issue. There is a tendency in
exchanges on these issues to force arguments into the timeworn mould
of creation vs Evolution. This is wide of the mark here. The issue
is: "what is good science?" I have used the recent book by Michael
Majerus to argue that the Peppered Moth research of Kettlewell and
the subsequent use of it by Darwinists in their textbooks is NOT an
example of good science. I regard Majerus's book as a helpful
contribution to correcting the popular misconceptions.

Kevin also wrote:
"It will be interesting to see if creationists on this listserv, such
as Art Chadwick, David Tyler and Vernon Jenkins, will admit they were
wrong about the demise of the peppered moth and post a retraction, or
will prefer to ignore their error ...."

I have read nothing in the recent posts that suggests to me that I
have made any errors of judgment on this matter. I would like to
repeat that my comments have been made in the interests of good
science. I am not interested in the part politics approach
to creation vs evolution.

> The bottom line is this: not only is the peppered moth scenario not dead,
> it isn't even sick; it is still considered to be an example of "evolution in
> action" even though the scenario is not as simple as it is frequently
> portrayed to be.

This is hardly a "bottom line" statement. Clearly, some "consider"
the Peppered Moth to be an example of evolution in action - but can
these views be defended scientifically (answer - no). Furthermore,
you say that the situation is not as simple as it is frequently
portrayed to be - but that is what the controversy is about! My
contribution to this debate is to say that we have almost NO
understanding of the factors associated with the population changes
in the Peppered Moth. Nothing has been revealed in the various
posts over the past two weeks that has indicated a basis in science
for understanding the observed changes. Opinions of commentators are
quoted, and they are of interest, but they do not equate with
legitimate conclusions drawn from scientific research.

Majerus is quoted as saying:
> "My view of the rise and fall of the melanic peppered moth is that
> differential bird predation in more or less polluted regions, together with
> migration, are primarily responsible, almost to the exclusion of other
> factors."

What has escaped my notice is the evidence for such a view. Birds
have been seen eating moths - but is that responsible for the changes
in the population of the light and dark forms? We do not know.
The Majerus quote continues:
> "My view of the story, is, I know, not held by all other entomologists or
> evolutionary biologists. However, in reviewing well over 100 papers written
> about this case, and having collected peppered moths in the wild for over 30
> years, I am unconvinced that there must be other important selective factors
> involved in the evolution of melanism in the peppered moth in Britain. My
> view may well be proved to be incorrect. However, if it is to be refuted,
> research into the case must continue and be amplified. Recently (New York
> Times, 12 November 1996), the eminent evolutionary biologist Dr Douglas I.
> Futuyma said of the peppered moth story: 'We don't know the whole story yet,
> but it should be possible to find out what it is'."

I do not think Majerus has his finger on the pulse here. His view is
not "correct" until it is refuted! Rather, it is a hypothesis which
has not been validated. I agree with the Futuyma quote - and point
out that he is saying something different to Majerus.

I thank Paul Nelson for his constructive post and the excerpt from
Theodore Sargent et al., "The 'Classical' Explanation of Industrial
Melanism: Assessing the Evidence," _Evolutionary Biology_30 (1998):

I would like to highlight two sentences:
And, without observations of
naturally resting moths, there can be no observations
of natural acts of predation on them. Thus, we have
no real knowledge of either the predators involved
or their impact with respect to survivorship and
fitness in even the best-studied species exhibiting
industrial melanism.

This is crucial, Kevin. The Peppered Moth can be used as the
"best example" of unnatural selection - but its relevance to the
Darwinian model of evolutionary change is undetermined. In my
opinion, any one interested in the integrity of science should affirm

Best regards,
David J. Tyler.