Peppered Moths: The Saga Continues

Most people who have taken a high school biology course probably remember learning about the peppered moth. It has become an iconic example of “evolution in action.” The moth Biston betularia comes in two basic varieties—light and dark. In wooded areas in England, the darker variety is believed to be more common in areas where the trees are darker due to pollution. Because darker moths are harder to see, it is believed they suffer less predation. The opposite is true in unpolluted areas where the trees are lighter and the light variety of the moth is believed to be more common.

For many years the original research on the peppered moth done by Bernard Kettlewell has been highly questioned mainly due to debate over where the moths rest on the trees in natural settings (see “Much Ado About Moths” for more detail). One opponent of the research, scientist Michael Majerus, initially criticized Kettlewell’s work and decided to conduct his own research on the peppered moth.

Unfortunately, he died before he could publish his research. Others working with him published a paper showing his findings that validate Kettlewell’s original research on the peppered moth. One of the paper’s authors stated, “The research is particularly noteworthy because it settles a decade-long controversy about whether the moths are a good example of natural selection at work.”

I would agree that peppered moths and many other examples show that variations in populations, such as color, can be advantageous to an organism in a given environment, allowing those with a particular trait to be more likely to survive. This is essentially the definition of natural selection. However, I disagree with Peter Reuell, a Physorg.com writer, about what it means.

Despite decades of research that showed the moths evolved in response to their environment, doubts began to surface in the late 1990s as some in the scientific community suggested that earlier studies weren’t very rigorous. Those criticisms were quickly picked up by creationists and intelligent design advocates, who used those doubts as evidence that natural selection itself was an incorrect explanation of the observed evolution.

Whether the peppered moth is an example of natural selection or not, is really not the point as there are many other good examples of natural selection. What creationists criticize regarding the peppered moth is equating natural selection with molecules-to-man evolution. Dr. Tommy Mitchell wrote on the peppered moth controversy several years ago:

The issue of Kettlewell’s shortcomings notwithstanding, the creationist has no problem with the results of his (and other subsequent researchers’) work. The concept that a less visible organism would survive better than a more visible one seems obvious in the extreme. . . . The creationist would agree that this population change represents natural selection. However, this change is most certainly not molecules-to-man evolution. Natural selection and molecules-to-man evolution are not the same thing, and many are led astray by the misuse of these terms.

No amount of posturing by the evolutionist can change the fact that these moths are still moths and will continue to be moths. The variation seen is simply the result of sorting and resorting of the genetic material present in the original moths. At no time has there been any new information introduced into the genome of the moth (which is what molecules-to-man evolution would require). There is no evidence of the beginnings of an intermediate form between the present moth and the creature it is destined to evolve into. Moths stay moths, fish stay fish, and people stay people, regardless of the great variety seen within each.

I’m very thankful for Majerus’ work, and it is a great example of how observational science works. A hypothesis is made and tested multiple times by multiple scientists and either shown to support or reject the initial hypothesis. However, when it comes to what this means in regard to how living things came to be in the past (historical science), the presuppositions of the scientists play a large role in how they interpret the science in the present and the conclusions they draw about the past. The evidence is clear, yet people “suppress the truth in unrighteousness,” and so “professing to be wise, they became fools” (Romans 1:18, 22).

Keep fighting the good fight of the faith!