A leading advocate of "intelligent design" on Wednesday questioned whether his critics have enough scientific evidence to discredit his ideas as he testified in a federal trial over whether the concept can be discussed in a public school biology class.
Lehigh University biochemistry professor Michael Behe testified for a third day on behalf of a school board that is defending its decision a year ago, to require students to hear a statement about intelligent design before ninth-grade biology lessons on evolution.
Behe contends that evolution cannot fully explain the biological complexities of life — such as the immune system and blood clotting — suggesting the work of an intelligent force. He specifically questions whether complex systems could have evolved gradually through natural selection and random mutation.
Eric Rothschild, a lawyer for eight families suing to have intelligent design removed from the Dover Area School District's biology curriculum, presented Behe with a stack of more than a half-dozen books written about the evolution of the immune system.
"A lot of writing, huh?" Rothschild said.
But Behe was unmoved, noting that "evolution" has multiple meanings.
"I am quite skeptical that they present detailed, rigorous models of the evolution of the immune system through random mutation and natural selection," he said.
Behe also defended his 1996 best seller, "Darwin's Black Box," which outlines his ideas, and said discussing intelligent design is educationally useful because it exposes students to differing views of evolution.
Dover's intelligent-design statement says that Charles Darwin's theory is "not a fact" and has inexplicable "gaps," and it refers students to a textbook, "Of Pandas and People," for more information about the concept.
Although the intelligent-design concept does not name the designer, the families who are suing argue that the policy essentially promotes the Bible's view of creation, and therefore violates the constitutional ban on the state establishment of religion.
Dover school superintendent Richard Nilsen was scheduled to testify for the defense when the trial resumed Thursday afternoon.
The trial began Sept. 26, and it could last through early November.
The plaintiffs are represented by a team put together by the American Civil Liberties Union and Americans United for Separation of Church and State. The school district is being represented by the Thomas More Law Center, a public-interest law firm based in Ann Arbor, Mich., that says its mission is to defend the religious freedom of Christians.