From Natural History, April, 2002, page 77
Mystery Science Theatre
The case of the secret agent.
(a reply to Detecting Design in the Natural Sciences by William A. Dembski)
William A. Dembski claims to detect "specified complexity" in living things and argues that it is proof that species have been designed by an intelligent agent. One flaw in his argument is that he wants to define intelligent design negatively, as anything that is not chance or necessity. But the definition is rigged: necessity, chance, and design are not mutually exclusive categories, nor do they exhaust the possibilities. Thus, one cannot detect an intelligent agent by the process of elimination he suggests. Science requires positive evidence. This is so even when attempting to detect the imprint of human intelligence, but it is especially true when assessing the extraordinary claim that biological complexity is intentionally designed.
In this regard, Dembski's archery and SETI analogies are red herrings, for they tacitly depend on prior understanding of human intellect and motivation, as well as of relevant causal processes. A design inference like that in the movie Contact, for instance, would rely on background knowledge about the nature of radio signals and other natural processes, together with the assumption that a sequence of prime numbers is the kind of pattern another scientist might choose to send as a signal. But the odd sequences found within DNA are quite unlike a series of prime numbers. Dembski has no way to show that the genetic patterns are "set up in advance" or "independently given."
Dembski has been promoted as "the Isaac Newton of information theory," and in his writings, which include the books he cites in the essay here, he insists that his "law of conservation of information" proves that natural processes cannot increase biological complexity. He doesn't lay out his case here, and a refutation would require too much space. Suffice it to say that a connection exists between the technical notion of information and that of entropy, so Dembski's argument boils down to a recasting of an old creationist claim that evolution violates the second law of thermodynamics. Put simply, this law states that in the universe, there is a tendency for complexity to decrease. How then, ask the creationists, can evolutionary processes produce more complex life-forms from. more primitive ones? But we have long known why this type of argument fails: the second law applies only to closed systems, and biological systems are not closed.
In the evolutionary process, an increase in biological complexity does not represent a "free lunch"—it is bought and paid for, because random genetic variation is subjected to natural selection by the environment, which itself is already structured. In fact, researchers are beginning to use Darwinian processes, implemented in computers or in vitro, to evolve complex systems and to provide solutions to design problems in ways that are beyond the power of mere intelligent agents.
If we really thought that genetic information was like the signal in Contact, shouldn't we infer we were designed by extraterrestrials? Intelligent-design theorists do sometimes mention extraterrestrials as possible suspects, but most seem to have their eyes on a designer more highly placed in the heavens. The problem is, science requires a specific model that can be tested. What exactly did the designer do, and when did he do it? Dembski's nebulous hypothesis of design, even if restricted to natural processes, provides precious little that is testable, and once supernatural processes are wedged in, it loses any chance of testability.
Newton found himself stymied by the complex orbits of the planets. He could not think of a natural way to fully account for their order and concluded that God must nudge the planets into place to make the system work. (So perhaps in this one sense, Dembski is the Newton of information theory.) The origin of species once seemed equally mysterious, but Darwin followed the clues given in nature to solve that mystery. One may, of course, retain religious faith in a designer who transcends natural processes, but there is no way to dust for his fingerprints.
Robert T. Peimock is an associate professor of science and technology studies and associate professor of philosophy in Michigan State University's Lyman Brig's School and department of philosophy. He is tlie author of Tower of Babel: The Evidence Against the New Creationism (MIT Press, 1999) and editor of Intelligent Design Creationism and Its Critics: Philosophical, Theological, and Scientific Perspectives (MIT Press, 2001).
Special Report: Intelligent Design?
The Challenge of Irreducible Complexity by Michael J. Behe
The Flaw in the Mousetrap by Kenneth R. Miller
Detecting Design in the Natural Sciences by William A. Dembski
Mystery Science Theatre by Robert T. Pennock
Elusive Icons of Evolution by Jonathan Wells