Originally published 19 June 2001
How to account for the diversity and complexity of life on Earth?
For the past century and a half, there have been two theories on the table.
One theory, evolution by natural selection, assumes that all life is related by common descent. Diversity and complexity are products of reproductive variations acted upon by competition, which leads to organisms ever more finely adapted to their environments. Simply, life pulls itself into diversity and complexity by its own bootstraps.
A second theory proposes that life is the product of design. This is the older and more widely-espoused theory, usually in the form of special creation by a transcendent deity. Recently, it has come to be called Intelligent Design, or simply ID, and has attempted to wrap itself in the mantle of science.
A sizable part of the population is all abuzz about Intelligent Design, including politicians, school committees, and a smattering of academics. Proponents of ID do not use the G‑word when specifying the designer, but they are almost invariably evangelical Christians who wish to preserve a continuously active role for God in an ongoing creation.
The new advocates of ID ask that their ideas be judged by scientific, not religious, criteria. OK, let’s see how well ID stacks up as a scientific alternative to Darwinism.
To gauge how well ID is doing as a platform for scientific research, I logged into the best database of the biological literature. A search for keyword “evolution” yielded 24,000 hits in the last decade. A search for “intelligent design” yielded not a single piece of research.
Evolution by natural selection remains the basis of every successful biological research program.
It is hard to imagine how ID might ever be a platform for scientific research. If one supposes that the world is the way it is because a transcendent designer acts willfully to make it so, then what conceivable scientific explanation can work? The whole point of science is to discover natural laws. Where is law if all is whimsy?
ID is not a program for scientifically understanding the world; it’s a program for surrendering our quest for scientific understanding.
Michael Behe, a biochemist at Lehigh University, gave ID its biggest intellectual boost with his idea that certain biological systems are “irreducibility complex.” According to Behe, such things as the human eye or blood clotting in animals involve such a complex interdependence of parts that it is impossible to imagine any sequence of individual mutations acted upon by natural selection that could have produced the entire system.
Most scientists would respond: It may be difficult to imagine how it happened, but not necessarily impossible. Rather than throwing up our hands at the beginning, let’s try to figure it out using the previously successful tools of evolutionary biology, or whatever other naturalistic explanations turn out to be necessary.
Recent years have seen a vast increase in our knowledge of life. In every case, naturalistic explanations were found because researchers assumed that naturalistic explanations are possible.
Behe’s argument for design, and those of other ID advocates such as William Dembski, all boil down to what biologist Richard Dawkins has called “the argument from personal incredulity”: If I can’t imagine how it happened, then it couldn’t have happened.
Which is exactly why ID isn’t science. All real science begins with “I can’t imagine how it happened, so let’s try to figure it out.” Behe and his allies are in the same category as 19th-century folks who said, “I can’t imagine how a big aluminum box could carry hundreds of people across the Atlantic at the speed of sound, so it must be impossible.”
As for the so-called evidence for intelligent design, one could equally well argue the opposite. Even a cursory knowledge of living systems makes it obvious that life is jerry-built and wasteful from the genes up, often violent and cruel. Biologist Ursula Goodenough writes: “Genomes are absurd. They really are. Small islands of meaningful genes and their regulatory modules floating in seas of meaningless sequences, each gene some crazy quilt of former ideas.”
Which is not what one would expect of an intelligent designer who is ever busy fiddling with the creation, but is exactly what one would expect from a world that contains within itself — blessedly and wonderfully, some would say divinely — the capacity for ever greater diversification and complexity.
