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July 7, 2004 9:36 PM

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The Evolution Debate

by Lee Helms

Andrew Zimmerman Jones' article "Heresy Today, Law Tomorrow: Evolution on Trial" in the October 2000 M-Pathy made some good points, but I feel that it left a couple of things unsaid.

One of the main friction points in the debate pitting evolution against creationism is the tug-of-war over the word "theory." By the time accredited scientists attach the word "theory" to an idea, they have developed a large body of credible, cross-disciplinary evidence favoring that idea over other ideas, and have explained how evidence that seemed to point to the other ideas is consistent with the newly minted theory. My dictionary (The American College Dictionary,Random House 1962) says "A theory properly is a more or less verified or established explanation accounting for known facts or phenomena: e.g. the theory of relativity."

Unfortunately, common usage has cheapened the word. In everyday parlance, "theory" is often used where the speaker means "hypothesis" or "speculation," and at worst, "theory" is used to mean "any hare-brained idea." Creationists have exploited this corruption of the word to try to disguise the vast difference in scientific credibility between evolution and creationism. By calling creationism "creation theory" they imply that it is equivalent to genuine scientific theories and, conversely, when referring to evolution, they say that it is "just a theory," implying that it's no better than speculation. Obviously, this kind of flexible definition of "theory" suits their purposes, but if language is to communicate rather than obfuscate, it must be used concisely, as it is used by scientists. Real scientists, not "creation science" advocates.

Another point I'd like to address is the notion of "irreducible complexity" -- the idea that some cellular or bodily structures are too complex to have developed step-by-step through evolution. It seems to me that resorting to that kind of all-or-nothing thinking generally reflects a serious lack of imagination.

Most often, I hear the argument for "irreducible complexity" phrased as the question, "what good is half an eye or half a wing?" It implies that these structures must appear all at once or not at all. This is usually followed by the claim that the intermediate forms proposed by evolutionary theory must be essentially a deformed version of the intended "final product," incomplete and therefore not competent in competition for survival.

Anyone who applies a bit of imagination to the problem of developing wings can easily figure that the bat probably has an ancestor that was similar to a flying squirrel -- a glider, rather than a true flyer. That animal, in turn, may well have had a squirrel-like ancestor that leaped from tree to tree. The evolution of the winged bat, then, would have been a gradual progression from leaper to glider to flyer, with each form being perfectly competent in its own environment and with each incremental change providing a survival advantage over the previous form as the animals' environment changed.

As for the origin of life itself, it has recently been found that some metabolic chemicals which are difficult to produce inorganically in the atmosphere or in shallow seas are synthesized easily under conditions that prevail at mid-ocean hydrothermal vents. Furthermore, experiments on bacteria seem to indicate that a mere 300 genes are enough to direct the life processes necessary for basic metabolism and reproduction. These findings, along with the results of previous origin-of-life experiments, show that science is making continuous progress toward explaining how life may have
arisen through repeatable, natural processes.

"Intelligent design" advocates often try to claim vindication from the fact that the puzzle of evolution hasn't yet been assembled completely. They argue that, since there are questions which evolutionary science can't answer with absolute certainty, RIGHT NOW, therefore "intelligent design" MUST be correct, whether there's evidence to support it or not. In scientific terms, this is called "jumping to conclusions." Real science does not proceed by that kind of process of elimination, it proceeds on the basis of positive evidence.

© 2000 by Lee Helms