The war of evolution vs. intelligent design rages on, with at least eight books on the topic being published in the first half of 2007.

The most controversial book in the continual debate will no doubt be Michael Behe's The Edge of Evolution: The Search for the Limits of Darwinism. Behe, a professor of biochemistry at Lehigh University with a Ph.D. from the University of Pennsylvania, was the Dover, Pa., school board's lead witness in the 2005 case in which the board was sued for trying to inject intelligent design into biology classes.

The Edge of Evolution (Free Press, June) furthers the argument for the scientific validity of ID, which Behe first made in 1996 in Darwin's Black Box, saying that certain highly complex molecular structures in the cell were "irreducibly complex" and thus could not have evolved but must have been designed by an intelligent designer.

In his new book, Behe says he now finds even more evidence for the role of a designer. Building his case from the intricate workings of proteins and complicated calculations of probability, he claims that design goes beyond the cell, reaching up the ladder of life to the development of vertebrates.

As a credible scientist (he has published in the prestigious journal Nature and the Proceedings of the National Academy of Sciences) whose first book sold 50,000 copies in hardcover and continues to sell at least 15,000 paperback copies a year (according to editor Bruce Nichols), Behe is a darling of the ID movement, and a favorite target of its opponents. "People turn Michael Behe into a football," says Nichols.

Indeed, Behe underwent a withering cross-examination by the plaintiffs' lawyer in Dover, and the presiding judge, John E. Jones III, wrote in his opinion that Behe's concept of irreducible complexity was scientifically "meaningless." Speaking of that experience, Behe says, "I had a very naïve idea of the legal system... not realizing it's the job of the other guy to make you look as bad as possible."

Even Behe's colleagues at Lehigh have distanced themselves from him: "We had department meetings where it was pretty much me against the world, and they put up a statement on the department Web site essentially disavowing intelligent design and pledging allegiance to Darwin's theory and saying that there's only one screwball in the department here who disagrees with this." He adds that there are people who seem to take it personally and "turn the other way" when they see him in the hallway.

A mild-mannered father of nine, Behe seems out of place at the center of a maelstrom. He admits he used to be a believer in Darwin's theory, until "in the late '80s I read a book called Evolution: A Theory in Crisisby Michael Denton, who is a geneticist in Australia.... That's what really knocked me off course, because I didn't have any answers to the problems Denton raised."

Which is when he began questioning Darwin's theory in the field he knew best—biochemistry. By the mid-'90s, Behe had met Phillip Johnson, the Berkeley law professor whose book Darwin on Trial is the foundational text of the ID movement, and then became a fellow at the pro-ID Discovery Institute. According to Behe, it was Johnson who directed the Free Press's Nichols to him when Nichols was looking for a book on ID. Behe was already at work on Darwin's Black Box, and his agents, Lynn Chu and Glen Hartley, submitted the manuscript to Nichols.

One of the key questions about ID's proponents is: are they being coy when they say that while they find scientific evidence of a designer, it's not necessary to conclude that the designer is God? Behe is a practicing Catholic who says he personally believes that God is the designer whose handiwork he sees in the complexities of the cell. Still, he, too, hews to the scientific line in insisting there's no evidence regarding the designer's identity. "The flagellum [a complex bacterial structure] doesn't have an autograph on it," he says.

But while Behe walks the scientific walk, he also talks the ID talk, referring to evolutionary theory as "Darwinism." And, as a contributor to the ID textbook Of Pandas and People(a key element in the Dover case), he objects to standard biology textbooks promoting scientific "materialism"—an ID buzzword that Behe defines as "explanations that exclusively involve matter, energy and chance" and omit "teleology... mind and purpose." "That's not science," he says of materialism. "That's a philosophy."

Behe's critics, on the other hand, argue that ID is theology, not science. But Behe feels "serenely confident that design will in fact be widely recognized or be a prominent player." And he may be right. In a new Newsweek poll, only 48% of those questioned believe evolution is "well-supported by evidence and widely accepted in the scientific community."