The Peppered Moths
Most peppered moths in England were light-colored in the early part of the nineteenth century, but during the industrial revolution in Britain the moth population became “melanic”, or dark-colored. Bernard Kettlewell performed experiments on these moths that became the classic textbook examples of natural selection in action. Kettlewell’s experiments suggested that predatory birds ate light-colored moths when they became more conspicuous on pollution-darkened tree trunks.
Most introductory biology textbooks illustrate the classical story of natural selection with photographs of the varieties of peppered moths resting on light and dark colored tree trunks. Most biologists have known for decades that the classical story has serious flaws. Peppered moths in the wild don’t even rest on tree trunks. In actuality, the photographs have been staged.
Finnish zoologist Kauri Mikkola reported in an experiment that the normal resting place of the peppered moth is beneath small, horizontal branches, high in the canopies. In twenty-five years of field work, Cyril Clarke and his colleagues found only one peppered moth naturally perched on a tree trunk. Scientists Tony Liebert and Paul Blakefield observed that the species rest predominately underneath or on the side of branches.
Pictures of peppered moths on tree trunks must be staged. Some are made using dead specimens that are glued onto the trunk, while other live specimens are manually placed in position. They remain there because they are lethargic during daylight hours-peppered moths are night fliers.
University of Massachusetts biologist Theodore Sargent told a Washington Times reporter in 1999 that he once glued some dead specimens on a tree trunk for a TV documentary about peppered moths. A Canadian textbook writer who knew that the peppered moths pictures were staged used them anyway. Bob Ritter was quoted as saying in the April 5, 1999 Alberta Report News magazine, “You have to look at the audience. How convoluted do you want to make it for a first-time learner?” Ritter explained, “We want to get across the idea of selected adaptation. Later on, they can look at the work critically.”
“Later on” can be much later. When University of Chicago professor Jerry Coyne learned of the flaws in the classical story in 1998, he was well into his career as an evolutionary biologist. Coyne was embarrassed when he finally learned that the peppered moth story that he had been teaching for years was a myth. “My own reaction” he wrote, “resembles the dismay attending my discovery at age six that it was my father and not Santa who brought the presents on Christmas Eve.”
There has been talk in the National Academy of Sciences that America’s universities should deny students admission if they have not been satisfactorily exposed to evolution. You have got to be kidding! The need to enforce Darwinian orthodoxy justifies the academic equivalent of holding children hostage.
The truth is that a surprising number of biologists quietly doubt or reject some of the grander claims of Darwinian evolution. But – at least in America – they must keep their mouths shut or risk condemnation.
It’s vitally important to remember that science is not the enemy. I love science in the form of fossils, experiments, measurements, research, and observation. In fact, most major disciplines in modern biology – including embryology, anatomy, physiology, paleontology and genetics – were pioneered by scientists who never heard of Darwinian evolution. Today’s students, who are exposed to half-truths and deliberate frauds of evolutionary biology, might turn away from science in disgust. I hope that this does not happen.