Why Scientists Reject Intelligent Design
Source Newsroom: Joseph Henry Press / National Academies Press
Newswise — Across the nation scientists have expressed outrage at President's Bush's recent statement that the mainstream scientific theory of evolution should be presented side-by-side with the competing, intellectually flaccid doctrine of intelligent design. "Both sides ought to be properly taught," he said, "so people can understand what the debate is about." How could the "education President" promote such quackery?
Like most of my colleagues, I'm troubled by the thinly-veiled anti-evolutionist subtext of Bush's comments, but I also see an educational opportunity in this debate. That's why I'll follow our President's advice in my George Mason University classroom next semester. One way to develop a critical understanding of what constitutes good science is to take a close look at bad science.
Proponents of intelligent design, or ID, argue that life on Earth is so extraordinarily complex that it could not possibly have emerged through any natural process. Life on Earth, they say, is "irreducibly complex," and to underscore their point they resort to a clever analogy. If you were to walk down a path and find a wristwatch lying on the ground, you would know by inspection that an unseen maker had designed the watch. The precise juxtaposition of various gears and catchments could not possibly have emerged spontaneously through any natural process. Similarly, according to ID proponents, one needs only to look at life on Earth to realize that no natural process could have led to its evolution. Look at the intricacies of the flagellum that propels a bacterium, or the flowering of a rose, or the structure of the human eye, and ID is self-evident. ID advocates tend to avoid the subject of God's role, but the question of who designed the designer (who must also be irreducibly complex) is always lurking in the wings.
Indeed, ID is a quasi-scientific brand of Creationism " the doctrine that life arose through miraculous intervention. The teaching of Creationism has been prohibited in the science curricula of public schools exactly because its precepts are based on faith, not reproducible observations. Creationism isn't science.
ID, on the other hand, does appear to fulfill the minimum criterion for a scientific hypothesis, which must make testable predictions that might be shown to be false. Proponents of ID do make predictions of a sort: "The flagellum is too complex to arise through natural processes," they say, or "The eye is irreducibly complex." It's possible, in principle, to falsify these statements by demonstrating a plausible, step-by-step pathway from simplicity to complexity. In spite of the negative nature of the predictions, ID is falsifiable and so it smells a bit like science.
But compare the pessimistic conclusions of ID to the predictive power of evolution by natural selection. The theory of evolution demands an unbroken, sequential, progressive history of life, and that's exactly what we observe in nature. Darwinian evolution makes specific testable predictions by the truckload, and those predictions have been confirmed by literally millions of observations of fossils, cells, genomes, vestigial organs, geological structures, animal behaviors " the list goes on and on. Anyone with a little training and an open mind can verify these observations.
What's more, we're beginning to get a theoretical handle on how such astonishing complexity might arise spontaneously in nature. The dynamic scientific field of emergent complexity challenges ID's basic assumptions of "irreducible complexity." We now realize that numerous natural systems of many interacting "agents" " systems as diverse as sand dunes, ant colonies, slime mold, and the conscious brain " display new and surprising behaviors not associated with the individual agents. Even if we don't yet know all the details of the process, the origins of cells and all their amazing adaptations fits this pattern of emergent complexity. Many of us in the field of origins research are confident that the problem of how it happened can be solved without invoking some external intervention.
And what's the ID alternative? To resort to some unknowable super-intelligence is hardly an intellectually satisfying option. Do we really want to throw up our hands and claim the problem is just too tough to solve? Indeed, ID turns out to be just another example of the tired old "God-in-the-gaps" reasoning. It implies that we have to resort to the supernatural every time there's some aspect of nature we don't fully understand.
For decades Creationists have used this strategy to attack the theory of evolution by natural selection. "Darwinists rarely mention the whale because it presents them with one of their most insoluble problems," claimed Creationist Alan Haywood in 1985. He pointed to the lack of intermediate forms between land animals and modern whales as an embarrassment to evolutionists. But good science thrives on such challenges. Subsequent targeted paleontological work on promising rock formations around the world has revealed a near-continuous sequence of dozens of fossil whales over the past 50 million years " a dramatic confirmation of Darwinian predictions. And, as the gap between cows and whales is filled, God's presumed creative role is squeezed into the production of ever more trivial variations.
Most scientists prefer to believe in a majestic universe of astonishing natural processes, in which designers need not meddle. Atoms and stars and cells and consciousness emerged inexorably, as did the intellect to discover laws of nature through a natural process of self-awareness and discovery.
Robert M. Hazen is Robinson Professor of Earth Science at George Mason University, Staff Scientist at the Carnegie Institution, and author of the forthcoming book, Genesis: The Scientific Quest for Life's Origin.