December 13, 2000
LETTER: Charges of fraud misleading

In recent weeks your newspaper has printed letters debating revisions in
high school biology curricula. Some of the correspondents have leveled
charges of fraud directed at evolutionists for attributing changes in the colors
of peppered moths to natural selection. As I am one of the evolutionary
biologists who study peppered moths, I feel obliged to comment. Charges of
fraud cannot be left unchallenged.

Some background about peppered moths is necessary. The common form of this
moth species is pale gray. About 150 years ago, a black specimen was
discovered near an industrial city in England. Over the years, the black
(melanic) form became ever more common as the pale form became rare. By
1900 the black form exceeded 90 percent in peppered moth populations
throughout the industrialized regions of England. The phenomenon was dubbed
industrial melanism.

Because people knew that birds eat insects, scientists as early as 1896
suspected that birds were eating the different color forms of peppered
moths selectively based on their degree of conspicuousness in habitats
variously blackened by industrial soot. Extensive experimental work supports this
view, although questions remain. Other scientists proposed that moths
responded to the presence of pollutants by developing darker body colors. We now
know from genetic analysis that the colors of adult peppered moths are
determined by genes; thus, the changes in the percentages of pale to black moths over
generations reflect changes in the genetic makeup of moth populations.

As industrial practices have changed in many regions, we have observed
black moths plummet from 90 percent to 10 percent in the just the past few
decades. Once again, we have observed significant genetic changes occur in
moth populations. Evolution is defined at the operational level as genetic
change over time, so this is evolution. Of the several factors known to
produce evolutionary change, only natural selection is consistent with the
patterns of the changes we see occurring in moth populations. Evolution
examined at this level is as well established as any fact in science.

We still have work to do. We do not all agree about the relative roles of
contributing factors, such as the flow of genes between moth populations
in different regions, the importance of lichens on trees, where on trees
moths might hide from predators, how important is differential predation,
and so on. As in any branch of science, participants endlessly debate
interpretations. Such wrangling is the norm, and it stimulates additional
research. That is how we make progress.

Our debates have never been secret. For recent overviews of the
controversies, please see http://www.wm.edu/biology/melanism.pdf or
www.els.net/elsonline/html/A0001788.html . Yet, unwarranted charges of
fraud, fakery and cover-ups repeatedly appear in letters printed in
newspapers. In your paper, Ms. Katrina Rider "asserts" the peppered moth story is a
hoax. She conveys the impression that dead moths were glued to trees as part of
a conspiracy of deception. She seems unaware that moths were glued to
trees in an experiment to assess the effect of the density (numbers) of moths on
the foraging practices of birds. Taken out of the context of the purpose
of the experiment, the procedure does sound ludicrous.

But, should we blame Ms. Rider for her outrage upon learning that moths
were glued to trees? No. Instead, I blame Dr. Jonathan Wells, who wrote
the article she cites as her source of information. While he has done no work
on industrial melanism, he has written opinion about the work. To one
outside the field, he passes as a scholar, complete with Ph.D. Unfortunately, Dr.
Wells is intellectually dishonest. When I first encountered his attempts
at journalism, I thought he might be a woefully deficient scholar because
his critiques about peppered moth research were full of errors, but soon it
became clear that he was intentionally distorting the literature in my
field. He lavishly dresses his essays in quotations from experts
(including some from me) which are generally taken out of context, and he systematically
omits relevant details to make our conclusions seem ill founded, flawed,
or fraudulent. Why does he do this? Is his goal to correct science through
constructive criticism, or does he a have a different agenda? He never
mentions creationism in any form. To be sure, he sticks to the scientific
literature, but he misrepresents it. Perhaps it might be kinder to suggest
that Wells is simply incompetent, but I think his errors are by
intelligent design.

Bruce Grant

http://bsgran.people.wm.edu/