NATURAL SELECTION, IRREDUCIBLE COMPLEXITY, AND THE BACTERIAL FLAGELLUM: A CONTRARIAN APPROACH TO THE INTELLIGENT DESIGN DEBATE

David Crump, University of Houston Law Center

Abstract

The subject is one about which many commentators have drawn battle lines, but this article is different. Even though the author concludes that natural selection is supported by overwhelming evidence, he maintains that teaching theories of irreducible complexity in public schools would be appropriate and desirable. Doing so would serve several secular purposes that would satisfy the first requirement of the Lemon test. First, irreducible complexity, which some proponents offer in support of theories of intelligent design, can be defended as scientific under some definitions of science, although not under others, and it therefore provides an ideal vehicle to address the question, “What is science?” The potential secular purposes also include spurring development of mainstream evolutionary theories, exploring epistemology, teaching methods of debate about mutually inconsistent arguments, and equipping students to analyze the claims of informed irreducible complexity proponents on a mature basis (and to reject them, if they so decide). Furthermore, censorship of irreducible complexity and intelligent design has a spillover effect that discourages discussion of other, undisputedly proper subjects. Open confrontation of the critique of natural selection furnished by these theories, together with the answers to this critique that support natural selection, would reduce this peripheral censorship.

Neutral presentation of irreducible complexity also can pass the second and third parts of the Lemon test. Although the subject can be presented improperly, in a way that advances or is entangled with religion, it need not be taught that way; and in this respect, irreducible complexity is just like evolution, which can also be taught improperly, so that it advances or inhibits religion. Standard methods of teaching natural selection, in fact, often include such forceful condemnations of teleological (i.e., purposive) theories that they implicitly raise issues about irreducible complexity and intelligent design already, if only so that the instructor can reject them dogmatically. Today, influential biologists take the condemnation of these alternative theories a step farther, and they openly offer the evidence for natural selection as support for a preferred religion of secular humanism. Irreducible complexity can be presented briefly, as a criticism of natural selection to which biologists have proposed answers, and it need not be given anything approaching equal time. Its inclusion in public school biology classes would serve valuable ends and could even produce a greater neutrality toward religion than does the teaching of natural selection alone.