Darwin slayer

Michael Behe's debut work, Darwin's Black Box: The Biochemical Challenge to Evolution (1996), was the Intelligent Design movement's magnum opus, its biggest book of the decade. Here was a biology professor (at Lehigh University, where he has taught since 1985) who could write well and develop good metaphors.

Behe's emphasis on "irreducible complexity" explained why chance mutations could not be the driving engine of macroevolutionary change. He showed how the complexity of organs and organisms means that not one mutation but dozens would have to kick in all at once, an event as improbable as would be the production by complete chance of a spring-driven mousetrap.

Now Behe is back with his second book, The Edge of Evolution: The Search for the Limits of Darwinism (Free Press, 2007). Those who wonder why he doesn't publish more often should know that he has nine children. But a book once every decade or so is about as much as Darwinians can take. Behe's new work shows that Darwinism's random mutation and natural selection explain little about how one species has led to another.

Behe's insistence that key mutations in the history of life must have been nonrandom, and that the universe is clearly designed for life, will infuriate Darwinian materialists. But he will also displease creationists, for he argues that "the evidence for common descent seems compelling." Modern DNA sequencing, he contends, shows that many creatures have common ancestors, and that God did not create man from dust.

WORLD: Compared to modern scientists, how much did Charles Darwin and other scientists of his day know about the nature of the cell and the fine-tuning that makes life possible?

BEHE: Darwin and his contemporaries knew very little about the cell, which is the foundation of life. Microscopes of that era were too crude to see many critical details. So 19th-century scientists thought the cell was simple "protoplasm," like a piece of microscopic Jell-O. Now we know that the cell is chock full of sophisticated nanotechnology, literally machines made from molecules. The same goes for the universe. In Darwin's era the universe was thought to be pretty simple. Now we know its basic laws are balanced on a razor's edge to allow for life, and that our planet may be the only one in the universe that could support intelligent life. The more we know about nature, the more design we see.

WORLD: The Edge of Evolution takes a long, hard look at malaria. Why is the lack of fundamental change among malaria cells over the past 50 years, since widespread drug treatments first appeared, evidence against Darwin?

BEHE: Suppose some fellow bragged that he could hurdle a tall building by first jumping up past the first floor, gaining a foothold, jumping from there to the second floor, and so on. But if you called him on it, and after a billion tries he hadn't made it even to the second floor, you'd know his boast was just bluster. Darwinism asserts that, given enough chances, by tiny steps random mutation and natural selection can build sophisticated molecular machinery. Yet given an astronomical number of chances over thousands of generations with malarial parasites that are under strong pressure from human drugs, no new or sophisticated machinery was found, only tiny changes in old machines. That gives us compelling reason to conclude Darwinism's boasts are bluster.

WORLD: You write that "HIV has killed millions of people, fended off the human immune system, and become resistant to whatever drug humanity could throw at it. Yet through all that, there have been no significant basic biochemical changes in the virus at all." Why is that significant in the debate over Darwin?

BEHE: Like malaria, HIV is a microbe that occurs in astronomical numbers. What's more, its mutation rate is 10,000 times greater than that of most other organisms. So in just the past few decades HIV has actually undergone more of certain kinds of mutations than all cells have endured since the beginning of the world. Yet all those mutations, while medically important, have changed the functioning virus very little. It still has the same number of genes that work in the same way. There is no new molecular machinery. If we see that Darwin's mechanism can only do so little even when given its best opportunities, we can decisively conclude that random mutation did not build the machinery of life.

WORLD: You show that "random mutation is almost certainly useless, even for the largest populations, when a flight of stairs is missing between biological floors." Please explain that metaphor.

BEHE: Darwinian evolution can be pictured as a walk up to the top of a building. Without stairs, the climb is impossible. If stairs are continuous, the walk is easy. If several stairs are missing, that can be a difficult barrier for a middle-aged couch potato like me. But a younger, fitter person would have no trouble jumping the gap. In evolutionary terms, the larger the population of a species, the fitter it is. But, although Darwin didn't know it, there are many biological steps, called "amino acids," between biological floors, and many are missing. As I show, even plentiful microbes have great difficulty jumping missing biological stairs to go from floor to floor. So we can conclude that life did not ascend by Darwinian evolution.

WORLD: If macroevolution is like taking a gradual route to a distant pinnacle, why is it biologically unreasonable-given enough time-"to expect random mutation and natural selection to navigate a maze to get there"?

BEHE: Darwin's most radical claim was that evolution is utterly blind-unlike an intelligent agent, it can't "see" whether a mutation will be helpful in the long run. Random mutation and natural selection can only select whatever changes confer an immediate advantage, regardless of whether the changes are constructive or destructive. We see that starkly in human genetic responses to malaria, where many genes have been broken, diminished, or warped (like sickle cell). Yet in order to build complex coherent molecular machinery, evolution must avoid destructive changes and select ones that will be helpful in the future. A blind process can't do that.

WORLD: Many Christians will object to your defense of common descent, but you state, "When two lineages share what appears to be an arbitrary genetic accident, the case for common descent becomes compelling." Why do you think the existence of similar broken genes in the genomes of humans and chimps proves their common descent?

BEHE: I should first emphasize that on the question of common descent, I wear just my scientist's hat. So if a person has strong theological reasons to question descent, then he may weigh the evidence differently than I do. Here's the way I see it: When we study humans with a common genetic disease (such as sickle cell), we can often trace it back to a single mutation in a human forebear. With a few more assumptions, the same reasoning can be applied between species. We humans share with other primate species what look for all the world like common genetic accidents. If we inherited those from a common ancestor, it would neatly explain why we all have them now. I find that persuasive.

WORLD: Your concluding section gives readers "something to ponder long and hard: Malaria was intentionally designed," and children die in a mother's arms "because an intelligent agent deliberately made malaria, or at least something very similar to it." Some of your conclusions seem deistic, and others suggest that we might be in the hands of a very angry God. After your research and pondering, where do you personally come out?

BEHE: I'm no deist. I'm a Christian who believes strongly in an active, loving God. Yet as C.S. Lewis insisted, Aslan is "not a tame lion." God answered Job's complaint of suffering not by denying it, but by His majesty and transcendence. God did not place us in a toy world, with all the sharp edges smoothed. Rather, along with the pleasant, He designed a world containing real physical danger: tigers with claws, and remarkable parasites with sophisticated molecular technology. We Christians especially should expect to suffer in this life and, much worse, to witness those dear to us suffer. Yet our faith assures us that through the mystery of suffering with Christ, God will draw out much good.