The following article originally appeared in the magazine The American Spectator, December 2000/January 2001, and is reprinted here in three parts by permission of the author and the magazine publisher. Part III will appear in a future edition of Creation in the Crossfire.
Survival of the Fakest
by Jonathan Wells
Science now knows that many of the pillars of Darwinian theory are either false or misleading. Vet biology texts continue to present them as factual evidence of evolution. What does this imply about their scientific standards?
Darwin’s Tree of Life
Darwin wrote in The Origin of Species: “I view all beings not as special creations, but as the lineal descendants of some few beings” that lived in the distant past. He believed that the differences among modem species arose primarily through natural selection, or survival of the fittest, and he described the whole process as “descent with modification.”
No one doubts, of course, that a certain amount of descent with modification occurs within species. But Darwin’s theory claims to account for the origin of new species in fact, for every species since the first cells emerged from the primordial ooze.
This theory does have the virtue of making a prediction: If all living things are gradually modified descendants of one or a few original forms, then the history of life should resemble a branching tree. Unfortunately, despite official pronouncements, this prediction has in some important respects turned out to be wrong.
The fossil record shows the major groups of animals appearing fully formed at about the same time in a “Cambrian explosion,” rather than diverging from a common ancestor. Darwin knew this, and considered it a serious objection to his theory. But he attributed it to the imperfection of the fossil record, and he thought that future research would supply the missing ancestors.
But a century and a half of continued fossil collecting has only aggravated the problem. Instead of slight differences appearing first, then greater differences merging later, the greatest differences appear right at the start. Some fossil experts describe this as “top-down evolution,” and note that it contradicts the” bottom-up” pattern predicted by Darwin’s theory. Yet most current biology textbooks don’t even mention the Cambrian explosion, much less point out the challenge it poses for Darwinian evolution.
Then came the evidence from molecular biology. Biologists in the 1970′s began testing Darwin’s branching tree pattern by comparing molecules in various species. The more similar the molecules in two different species are, the more closely related they are presumed to be. At first, this approach seemed to confirm Darwin’s tree of life. But as scientists compared more and more molecules, they found that different molecules yield conflicting results. The branching-tree pattern inferred from one molecule often contradicts the pattern obtained from another.
Canadian molecular biologist W. Ford Doolittle doesn’t think the problem will go away. Maybe scientists “have failed to find the ‘true tree,’” he wrote in 1999, “not because their methods are inadequate or because they have chosen the wrong genes, but because the history of life cannot properly be represented as a tree.” Nevertheless, biology textbooks continue to assure students that Darwin’s Tree of Life is a scientific fact overwhelmingly confirmed by evidence. Judging from the real fossil and molecular evidence, however, it is an unsubstantiated hypothesis masquerading as a fact.
They All Look Alike:
Homology in Vertebrate Limbs
Most introductory biology textbooks carry drawings of vertebrate limbs showing similarities in their bone structures. Biologists before Darwin had noticed this sort of similarity and called it “homology,” and they attributed it to construction on a common archetype or design. In The Origin of Species, however, Darwin argued that the best explanation for homology is descent with modification, and he considered it evidence for his theory.
Darwin’s followers rely on homologies to arrange fossils in branching trees that supposedly show ancestor-descendant relationships. In his 1990 book, Evolution and the Myth of Creationism, biologist Tim Berra compared the fossil record to a series of Corvette models: “If you compare a 1953 and a 1954 Corvette, side by side, then a 1954 and a 1955 model, and so on, the descent with modification is overwhelmingly obvious.”
But Berra forgot to consider a crucial, and obvious, point: Corvettes, so far as anyone has yet been able to determine, don’t give birth to little Corvettes. They, like all automobiles, are designed by people working for auto companies. In other words, an outside intelligence. So although Berra believed he was supporting Darwinian evolution rather than the pre-Darwinian explanation, he unwittingly showed that the fossil evidence is compatible with either. Law professor (and critic of Darwinism) Phillip E. Johnson dubbed this “Berra’s Blunder.”
The lesson of Berra’s Blunder is that we need to specify a natural mechanism before we can scientifically exclude designed construction as the cause of homology. Darwinian biologists have proposed two mechanisms: developmental pathways and genetic programs. According to the first, homologous features arise from similar cells and processes in the embryo; according to the second, homologous features are programmed by similar genes.
But biologists have known for a hundred years that homologous structures are often not produced by similar developmental pathways. And they have known for thirty years that they are often not produced by similar genes, either. So there is no empirically demonstrated mechanism to establish that homologies are due to common ancestry rather than common design.
Without a mechanism, modem Darwinists have simply redefined homology to mean similarity due to common ancestry. According to Ernst Mayr, one of the principal architects of modern neo-Darwinism: “After 1859 there has been only one definition of homologous that makes biological sense: Attributes of two organisms are homologous when they are derived from an equivalent characteristic of the common ancestor.”
This is a classic case of circular reasoning. Darwin saw evolution as a theory, and homology as its evidence. Darwin’s followers assume evolution is independently established, and homology is its result. But you can’t then use homology as evidence for evolution except by reasoning in a circle: Similarity due to common ancestry demonstrates common ancestry.
Philosophers of biology have been criticizing this approach for decades. As Ronald Brady wrote in 1985: “By making our explanation into the definition of the condition to be explained, we express not scientific hypothesis but belief. We are so convinced that our explanation is true that we no longer see any need to distinguish it from the situation we were trying to explain. Dogmatic endeavors of this kind must eventually leave the realm of science.”
So how do the textbooks treat this controversy? Once again, they ignore it. In fact, they give students the impression that it makes sense to define homology in terms of common ancestry and then turn around and use it as evidence for common ancestry. And they call this “science.”
Nothing a Little Blue Can’t Fix:
The Peppered Moths
Darwin was convinced that in the course of evolution, “Natural Selection has been the most important, but not the exclusive, means of modification,” but he had no direct evidence of this. The best he could do in The Origin of Species was give “one or two imaginary illustrations.”
In the 1950′s, however, British physician Bernard Kettlewell provided what seemed to be conclusive evidence of natural selection. During the previous century, peppered moths in England had gone from being predominantly light-colored to being predominantly dark-colored. It was thought that the change occurred because dark moths are better camouflaged on pollution-darkened tree trunks, and thus less likely to be eaten by predatory birds.
To test this hypothesis experimentally, Kettlewell released light and dark moths onto nearby tree trunks in polluted and unpolluted woodlands, then watched as birds ate the more conspicuous moths. As expected, birds ate more light moths in the polluted woodland, and more dark moths in the unpolluted one. In an article written for Scientific American, Kettlewell called this “Darwin’s missing evidence.” Peppered moths soon became the classic example of natural selection in action, and the story is still retold in most introductory biology textbooks, accompanied by photographs of the moths on tree trunks.
In the 1980′s, however, researchers discovered evidence that the official story was flawed including the pertinent fact that peppered moths don’t normally rest on tree trunks. Instead, they fly by night and apparently hide under upper branches during the day. By releasing moths onto nearby tree trunks in daylight, Kettlewell had created an artificial situation that does not exist in nature. Many biologists now consider his results invalid, and some even question whether natural selection was responsible for the observed changes.
So where did all those textbook photos of peppered moths on tree trunks come from? They were all staged. To expedite things, some photographers even glued dead moths to trees. Of course, the people who staged them before the 1980′s thought they were accurately representing the true situation, but we now know they were mistaken. Yet a glance at almost any cur- rent biology textbook reveals that they are still being used as evidence for natural selection.
In 1999, a Canadian textbook-writer justified the practice: “You have to look at the audience. How convoluted do you want to make it for a first time learner?” Bob Ritter was quoted as saying in the April 1999 Alberta Report Newsmagazine. High school students “are still very concrete in the way they learn,” continued Ritter. “We want to get across the idea of selective adaptation. Later on, they can look at the work critically.”
Apparently, the “later” can be much later. When University of Chicago Professor Jerry Coyne learned the truth in 1998, he was well into his career as an evolutionary biologist. His experience illustrates how insidious the icons of evolution really are, since they mislead experts as well as novices.