The Discovery Institute vs. The Peppered Moth

The Discovery Institute claims that a new paper in the Journal of Evolutionary Biology has “debunked” the peppered moth icon of natural selection. They write:

A new paper in the Journal of Evolutionary Biology helps debunk the peppered moth icon, and cites Discovery Institute's Jonathan Wells in the process.

You wouldn't know it from the summary on PhysOrg, or from the abstract of the paper in the Journal of Evolutionary Biology, but some South Korean scientists have joined in the cause to dismantle a celebrated "Icon of Evolution," the myth of the peppered moth. That's right; in the first paragraph, Kang, Moon, Li and Jablonski set right to work, pulling the rug out from Kettlewell (1955) and all his copycats who made the peppered moth Exhibit A for the power of natural selection.

The focus of the post is that the Korean authors observed the moths Hypomecis roboraria and Jankowskia fuscaria to see where they rested on tree trunks and concluded that once they rested, they moved around on the bark, changing their orientation in order to more carefully conceal their appearance. Thus, they argue that it is a combination of color and resting behavior that contribute to their camouflage, not just the color alone. To this, the writer of the post responds:

In the real world, as opposed to the staged peppered-moth photos we have all seen in textbooks, the moths would not have stood out like sore thumbs on the tree trunks. They would have wandered about for a place to blend in; most likely, they would not have landed in such conspicuous spots in the first place (Wells, p. 148). Letting the moths do what comes naturally is what the experimenters should have done. The old peppered moth experiments, consequently, have been invalidated (again).

First, the authors seem to forget that Majerus (whom they cite) actually conducted comprehensive experiments that did not involve nailing moths to trees and his results corroborated earlier results that wing color was highly selective. The DI post author even admits that.

The odd thing about this post is that the author(s?) have made the logical non sequitur that behavior and morphology are completely divorced from each other. I know of no evolutionary biologist that would make that claim. Behavior always plays a role in evolution. If you take any animal out of its environment, it behaves differently. Sometimes that behavior can adapt to new environments, sometimes it cannot.

When Homo ergaster started using stone tools as weapons and started hunting, it changed what they could eat (and reduced the number of animals that could eat them), which allowed them to expand their home range. It also allowed them to outcompete their neighbors, in this case Australopithecus boisei, which likely caused the latter's extinction. Behavior and selection have always been intricately linked and there are literally thousands of examples of this.

The post writers argue that supporters of natural selection have “yielded some highly significant ground.” How? We already know from Majerus' work that the earlier results, if not technically or scientifically rigorous, were corroborated. The work of the Korean scientists simply adds the explicit role of behavior. Nobody doubts that selection is acting on wing color.

The author ends by writing:

And finally, the paper shows that criticisms of Darwinism by ID writers like Dr. Wells are having an impact -- even in the Journal of Evolutionary Biology.

It does no such thing. Wells is cited three times, and only in passing. His work is never discussed in any depth. The author remarks that the Korean scientists have picked up the word "iconic" from Wells. So? When I write for BioLogos, I regularly cite anti-evolution authors. I might even use one of their phrases. That does not mean that I agree with them or endorse their views. To say that Wells is having an impact might be true and it might not be. From this paper, however, that, like the claim that the peppered moth research has been debunked, is not in evidence