Peppered Moths and the Confused IDiots

I'm teaching part of a course on Popular Scientific Misconceptions. In my section we'll be talking about the evolution/creationism controversy and part of the discussion involves analysis of the techniques used by Jonathan Wells to denigrate evolution in his book Icons of Evolution. One of the chapters is Peppered Moths.

Creationists used to love the peppered moth story because they thought the evidence had been refuted by modern science. They were wrong, and most creationists will admit it. Not Jonathan Wells. He says,

Industrial melanism in peppered moths shows that the relative proportions of two pre-existing varieties can change dramatically. This change may be due to natural selection, as most biologists familiar with the story believe. But Kettlewell's evidence for natural selection is flawed., and the actual causes of the change remain hypothetical. As a scientific demonstration of natural selection—as "darwin's missing evidence"—industrial mealanism in peppered moths is no better than alchemy.

Open almost any biology textbook dealing with evolution, however, and you'll find the peppered moth presented as a classical demonstration of natural selection in action—complete with faked photos of moths on tree trunks. This is not science by myth-making.

Unfortunately for poor old Jonathan, the original work of Kettlewell has been replicated and natural selection is the explanation. The creationists were recently dealt a serious blow when Michael Majerus reported the results of his observations on peppered moths to the European Society for Evolutionary Biology. So what do they do now?

Denyse O'Leary thinks there's still propaganda to be made from the peppered moth story so she links to an article from last week that shows the new strategy. Denyse's link is here [Evolution in the light of intelligent design encyclopedia - new entries]. The article by David Tyler is The Peppered Moth: when will Darwinians admit that mistakes have been made?.

I'm going to quote part of David Tyler's article. I swear I'm not making this up.

The concluding words of Majerus' lecture are these: "If the rise and fall of the peppered moth is one of the most visually impacting and easily understood examples of Darwinian evolution in action, it should be taught. It provides after all: The Proof of Evolution." This quote explains why the issue is still important: Darwinists have always sought to use the peppered moth story as a proof of Darwinian evolution. This is a burden that cannot be carried by the evidence. Even with Majerus' new improved methodology, we have an example of natural selection within the peppered moth population with differential predation being the causal mechanism. It is an extraordinary mental leap to go from this to the origin of novelty, complexity and new body plans - which remain the central challenges for any theory of evolutionary transformation.

Okay, let's take this slowly so that even IDiots like David Tyer and Denyse O'Leary can understand.

It is absolutely safe to say that if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I’d rather not consider that).

Richard DawkinsWhen people like Majerus talk about evolution they're talking about the process of evolution. In this case he's referring to the process of evolution by natural selection within populations. He is perfectly correct in saying that the peppered moth date is proof that evolution occurs. It's proof of Darwinian evolution.

The problem with the IDiots is that they don't even understand what evolution is. Evolution does not require the creation of new body plans and the peppered moth example does not pretend to account for such things directly. All it does is show that evolution by natural selection is an observable fact.

Is it scientifically defensible to find an example of natural selection within a population of an animal, and then use this as an evidence for evolutionary transformation from the first single cell to the extraordinary diversity of life that we find in the biosphere?

No.

When this simple question is answered with a negative, then we can have a more constructive dialogue.

David, or Denyse, I'm ready whenever you are. To start with, do you understand the minimal definition of evolution [What Is Evolution?]. Get back to me when you do.

---

[Photo Credit: The photographs are from bill.srnr.arizona. The original source is unknown.]