Intelligent Design or Not-so-Intelligent Design?
Lead: Andrew Middleton

4/8/2008

Summary by Bradford Larsen

A Discussion of Intelligent Design

On several occasions in recent years the media has focused on legal proceedings regarding the teaching of Intelligent Design in public schools as an alternative to evolution. In Dover, Pennsylvania, in 2005, Intelligent Design was ruled to be unscientific and an attempt to teach religion in the classroom, and as such violates the First Amendment.

Intelligent Design as supported in Dover is an example of a teleological argument for the existence of God. These kinds of arguments claim that teleology or purpose can be seen in some aspect of the observable world, and that such purpose is evidence of a divine creator. Central to the Intelligent Design argument is the notion of irreducibly complex. An irreducibly complex system is a system that will cease to have any function if even one of its parts is not present. The Intelligent Design argument can be stated as follows:

1. There are biological systems that are irreducibly complex.

2. If a biological system is irreducibly complex, then it must have been designed.

We shall see that there are problems with both points of this argument.

Kenneth Miller, professor of biology at Brown University and witness in the Dover trial, contests the claim that there are irreducibly complex biological systems. Three oft-touted examples are the eye, the blood-clotting cascade, and the bacterial flagellum. He claims that they are not, in fact, irreducibly complex, and that as we conduct more research their evolutionary explanations become better justified.

The eye, once the poster child of irreducible complexity, now has a plausible evolution story. A very simple eye that has no capacity for movement and can only differentiate between two intensities - “light" and “dark" - could provide a reproductive advantage to its possessor. A more sophisticated eye that also has directionality could be even more beneficial. These and other anatomical developments of the eye are supported by the fossil record.

The blood clotting mechanism is another biological system claimed to be irreducibly complex. However, there are other organisms such as puffer fish, dolphins, and whales whose clotting systems lack some protein components that are present in the human clotting system. If the system were indeed irreducibly complex, it would not function as it does with fewer components in other organisms.

The flagellar motor found on bacteria is another supposedly irreducibly complex system. Consisting of about 50 biological components, it allows motility to the bacteria on which it is found. If it were irreducibly complex then it must have no function when some parts are not present. However, a Type 3 Secretory System - typically used by bacteria to inject chemicals into other cells, and found in the bacteria that cause the bubonic plague - contains only 10 of the 50 components. It is believed that such a secretion system evolved into the flagellar motor.

However, there are subtleties to Miller's explanation that are glossed over, points out Thomas Davis, professor of plant biology at the University of New Hampshire. “The literal claim that a system will not work when missing a single part is often correct. But there is a more complex story of homology to tell." Homology refers to the similarity of form in biological systems. In the case of the blood clotting system and the flagellar motor, the simpler systems provided as counterexamples are not derived from removing parts, but rather evolved alongside the more complex systems. If a flagellar motor had 40 of its parts removed, it would not become a secretion system. Miller likely glossed over the details in his refutation because he was communicating with non-specialists.

Although the first claim is literally true, the second claim - that irreducibly complex biological systems must have been designed - does not follow, due to homology.

Apart from the flaws of its central argument, Intelligent Design is impotent as a scientific theory. As Willem deVries, professor of philosophy, points out, even if there does happen to be a designer, Intelligent Design lacks explanatory power. Assuming design fails to give any insight into the nature of the designer or as to how the design was implemented.

The result of the Dover Trial affirms this conclusion. There it was determined that the textbook promoting Intelligent Design, Of Pandas and People, was in fact a revision of an older creation science textbook that was not allowed in the science classes of public schools, where instances of creation-related words were changed to less politically charged “design" words.

Because Intelligent Design doesn't discuss the nature of the designer, we are left to wonder. Does the designer sporadically intervene, acting as the so-called \God of the Gaps"? Or did the designer plan everything so well from the beginning that the system is self-contained? “The Intelligent Design proponents make no specific claims on this," Davis says. deVries disagrees: the proponents say there are irreducibly complex biological systems that could not have come into existence through undirected means, and so the designer must intervene.

One might suppose that the designer might not be supernatural - a highly advanced alien race, for example - an idea seriously considered by science fiction author Carl Sagan. Austin Purves, a student in the class, raised this point. However, this view is problematic: if we suppose that the living organisms we have encountered were designed by non-supernatural creatures, it is certain that the designers would themselves have irreducibly complex systems and show evidence of design. Who would have designed the designers? Without moving outside of naturalistic explanation, this question leads to an infinite regress. (On the other hand, a corollary of most ontological arguments for the existence of God would render the same question asked about an omniscient, omnipotent, omni-benevolent deity incoherent.) By this reasoning it seems that the Intelligent Design movement is a form of creationism rather than science, a view affirmed by the court in Dover, Pennsylvania.

The apparent conflict between science and religion is a largely a result of attempting to use religion for the wrong purposes, says deVries. \We need to realize that religion, sanctity, prayer, worship, etc. do not compete with science and math for explanation of the universe. Rather, the point of religion is to show how to lead a good life." He continues: \I'm happy thinking of science as providing the ultimate explanation of how things work. But not every question we want to ask is a question about how things work. Most importantly, we want to know what we should do - and science can give us help only concerning the means, not the ends, of our action."