Chadwick>> But it never stops. Either evolutionists know there is no
other widely believed "just so" story equivalent to or better than the
peppered moth story in explanatory value, or they are just plain ignorant.
Such evolutionists are taking a beating in my classes, and I presume in the
classes of other informed scientists. I cite from the latest edition of
the most popular college biology textbook, Solomon, Davis and Martin
"General Biology" 1999 edition, p. 9 and 10. This story serves as the only
cited evidence in the introductory chapter for their contention that
"Evolution is the primary unifying concept in Biology". If this were not
so sad it would truly be laughable... <<
Well we know what Mr. Chadwick and other anti-evolutionists have to say on
this, and want they want everyone else to believe, but what do the
scientists who actually work on the peppered moth and industrial melanism
have to say about the status of the peppered moth example? Let's take a
look.
In the UK we have Michael Majerus, whose book on industrial melanism
inadvertently touched off this anti-evolutionist canard:
"Indeed, Coyne tries to put words in my mouth by saying I should have used
"perhaps" rather than probably, in relation to the evolution of melanism in
Biston involving pollution and bird predation. I do not even say probably.
Indeed, on page 155, I say that my view is that
bird predation is of primary import, possibly to the exclusion of
everything else."
"To end, may I put on record to you, that my view is that the rise and fall
of the carbonaria form of the peppered moth has resulted from changes in
the environments in which this moth lives. These changes have come about
as a result on changes in pollution levels which have altered the relative
crypsis of the forms of this moth. The main, if not the only selective
factor that has lead to changes in the frequencies of the forms over time
is differential bird predation. The case of melanism in the peppered moth
IS ONE OF THE BEST EXAMPLES OF EVOLUTION IN ACTION BY DARWIN'S PROCESS OF
NATURAL SELECTION that we have. In general it is based on good science and
it is sound."
"Evidence of selective predation in the peppered moth is not lacking. It
is just not provided in the quick text book descriptions of the peppered
moth. How can it be...Of all the people I know, including both amateur and
professional entomologists who have experience of this moth, I know of none
who doubts that differential bird predation is of primary importance in the
spread and decline of melanism in the peppered moth."
[All of the above are excerpts from personal communications from Majerus
to Don Frack, which Don originally posted to this list back when this issue
first came up.]
Now we have Bruce Grant one of the foremost experts on the subject in the
US:
"Indisputable Evidence for Natural Selection
Textbook accounts of industrial melanism too often dwell in the
past. They begin with pre-industrial England and end with Kettlewell. As
a footnote they might add that melanism has been on the decline in recent
years following clean air legislation. Yet, it is the record of the
_decline_ that is by far the strongest. During the last century and the
early part of this one few people kept records about morph frequencies, so
our picture of the rise and spread of melansim is sketchy. Documentation
of the decline in melanic frequencies is vastly more detailed...No other
evolutionary force can explain the direction, velocity, and magnitude of
the changes except natural selection. That these changes have occurred in
parallel fashion in two directions, on two widely separated continents, in
concert with changes in industrial practices suggests the phenomenon was
named well. The interpretation that visual predation in a likely driving
force is supported by experiment and is parsimonious given what has been so
well established about crypsis in other insects. Majerus allows that the
basic story is more complicated that general accounts reveal, but it is
also true that none of the complications so far identified have challenged
the role assigned to selective predation as the primary explanation for
industrial melanism in peppered moths. Opinions differ about the relative
importance of migration and other forms of selection. It is essential to
define the problems, to question assumptions, and challenge dogma. This is
norm in all active fields of research. Majerus has succeeded admirably in
communicating this excitement to the reader. I would add this: Even if all
of the experiments relating to melanism in peppered moths were jettisoned,
we would still possess the most massive data set on record documenting what
Seawall Wright(1978) called "...the clearest case in which a conspicuous
evolutionary process has been actually observed." Certainly there are
other examples of natural selection. Our field would be in mighty bad
shape if there weren't. Industrial melanism in the peppered moth remains
one of the best documented and easiest to understand. [Bruce S. Grant,
_Fine Tuning The Peppered Moth Paradigm_, Book Review (of Majerus's book)
in _Evolution_ 53(3), 1999, p. 984 ]
So here we have two of the worlds experts on industrial melanism and the
case of the peppered moth who both seem to think that it is still a
perfectly good example of natural selection in action.
I would like to ask Mr. Chadwick if he considers Majerus and Grant to be
among the ignorant which he referred to? Or are they in his opinion merely
not informed scientists such as himself?
Bye
Troy Britain (Amateur Naturalist)
"It is so easy to hide our ignorance under such expressions as the `plan of
creation,' `unity of design,' &c., and to think that we give an explanation
when we only restate a fact. Any one whose disposition leads him to attach
more weight to unexplained difficulties than to the
explanation of a certain number of facts will certainly reject my theory."
- Charles Darwin.