PROVO, Utah — According to Michael Behe, there are limits to what evolution can explain.
Behe spoke on Friday, Oct. 16, at BYU during the Wheatley Institution's "Symposium on Responding to the New Atheism." He quoted a statement signed by 39 Nobel award recipients that says Darwinian evolution was the "unguided, unplanned process of random variation and natural selection."
For Behe, however, evolution via random and gradual mutations can't explain some very complex biological systems or "machines." Biology shows signs of an intelligent designer.
"You deduce design from the physical structure of a system," said Behe, a Catholic and a Lehigh University professor of biochemistry.
A simple example of deducing design, Behe said, would be the difference between looking at an ordinary mountain and looking at Mount Rushmore. One appears to be random; the other shows unmistakable signs of design. "It's not mystical. It's an everyday deduction."
"Everyone agrees that aspects of biology strongly appear to be designed," Behe said. Even one of the leading voices of the new atheism, author Richard Dawkins, wrote in "The Blind Watchmaker" that "biology is the study of complicated things that give the appearance of having been designed for a purpose."
Of course, Dawkins doesn't believe biological structures were a product of intelligent design, but he admits they "overwhelmingly impress us with the appearance of design."
"There are structural obstacles to Darwinian evolution," Behe said. "There are physical reasons to think that it can not do what its proponents claim for it."
Behe calls those structural reasons "irreducible complexity." He said it contradicts the premise that evolution could operate slowly and gradually one mutation at a time. An irreducibly complex structure couldn't evolve that way: "You have some system and it has a number of parts and they act on each other and they are all necessary for the function to exist. You take away one or more of the parts and the function is no longer present."
By analogy, Behe offers the mousetrap. A mousetrap has various parts: a spring, a wire "hammer," a catch, a board that holds it all together. Take away any part and you have a meaningless and purposeless collection of parts. There is no way, according to Behe, that it could slowly evolve into that complexity.
A bacterial flagellum is a real example of just such a system. The flagellum is a whiplike propeller that a bacterium spins to move. Any part of the flagellum apparatus, without all the rest, is purposeless. "Like a mousetrap without one of its necessary parts, this one would be broken as well," Behe said.
Behe said critics have responded to his argument about irreducible complexity with "wishful thinking" that someday they will be able to explain them by random events instead of intelligent design. Behe said many continue to make "grand Darwinian claims" as if this evidence already had been discovered. "They are urban legends."
Evolution can explain many things, according to Behe. But not everything. He believes there is an edge to Darwinian evolution. At that edge is intelligent design — the intervention of a designer.
e-mail: mdegroote@desnews.com