When the Kansas State Board of Education decided to hold hearings this spring on what the state's schoolchildren should be taught about evolution, Dr. Kenneth R. Miller was invited to testify. Lots of people thought he was a good choice to speak for science.

Thad Allender/Associated Press

Listening to opposing sides of the evolution debate last month in Topeka, Kan.

Forum: Human Origins

Dr. Miller is a professor of biology at Brown University, a co-author of widely used high school and college biology texts, an ardent advocate of the teaching of evolution - and a person of faith. In another of his books, "Finding Darwin's God," he not only outlines the scientific failings of creationism and its doctrinal cousin, "intelligent design," but also tells how he reconciles his faith in God with his faith in science.

But Dr. Miller declined to testify. And he was not alone. Mainstream scientists, even those who have long urged researchers to speak with a louder voice in public debates, stayed away from Kansas.

In general, they offered two reasons for the decision: that the outcome of the hearings was a foregone conclusion, and that participating in them would only strengthen the idea in some minds that there was a serious debate in science about the power of the theory of evolution.

"We on the science side of things strong-armed the Kansas hearings because we realized this was not a scientific exchange, it was a political show trial," said Eugenie Scott, director of the National Center for Science Education, which promotes the teaching of evolution. "We are never going to solve it by throwing science at it."

The American Association for the Advancement of Science, a large organization of researchers and teachers, and the publisher of the journal Science, also declined to participate.

"If the evidence for modern Darwinian theory is so overwhelming, they should have called the bluff on the other side and come and made their arguments," said John West, a political scientist and a senior fellow at the Discovery Institute, a research organization that supports work challenging the theory of evolution. "They should have put up or shut up."

Dr. West said that although most of the institute's resources support research on intelligent design, the theory that life on earth is far too complex to have evolved without the guidance of an intelligent agent, the organization does not advocate that students be required to learn it. Nor does it object to the teaching of evolution, he said.

"The majority of biologists obviously support Darwinian evolution in its full-fledged view," he said. "The question is, are there legitimate, peer-reviewed criticisms? If there are, students should know about them."

In theory, this position - "teach the controversy" - is one any scientist should support. But mainstream scientists say alternatives to evolution have repeatedly failed the tests of science, and the criticisms have been answered again and again. For scientists, there is no controversy.

Dr. Miller said he decided to stay away from the hearings because he was convinced that the panel would recommend a "teach the controversy" approach regardless of the testimony presented. "The people running things were people whose minds were already made up," Dr. Miller said in an interview in May, before the panel's recommendations were announced.

He said he had anticipated that "they would say, 'This is such a fascinating controversy that what we need to do is let the children of Kansas have the same benefit' " of learning about it.

When the hearings ended, the subcommittee running them concluded just that. The hearings had produced "credible scientific testimony that indeed there are significant debates about the evidence for key aspects of chemical and biological theory," the panel said, and it is "important and appropriate for students to know about these scientific debates."

Still, scientists who stayed away say they did the right thing.

Declining to testify "can be made to look as if you do not want to defend science in public, or you are too afraid to face the intelligent design people in public," Dr. Miller said.

But, he said, taking part in this kind of argument only contributes to the idea that there is something worth arguing about, and "I wasn't interested in playing a role in that."

Dr. Alan I. Leshner, chief executive of the American Association for the Advancement of Science, said that when the association was invited to present its views at the hearings he raised the issue with his board. Although some members said "go straighten them out," he recalled, the consensus was that the association should stay away.

"We were invited to debate one supposed theory against another," Dr. Leshner said, when in fact there was no credible scientific challenge to the theory of evolution.

Dr. Scott said that until recently she believed scientists should seize opportunities to debate the opponents of evolution. "I was one of the holdouts, saying yes, appear with these guys, yes, tell them what is wrong with their ideas, go to their conferences, treat them like scholars," she said.

Like other scientists, she said that if someone identified a flaw in evolutionary theory that could not be dealt with, science would have to modify the theory or even scrap it. But the criticisms raised have fallen in the face of scientific scrutiny, she and others say, yet opponents of evolution raise them again and again.

So a few years ago, she said, "even I threw in the towel."

"Our willingness to engage their ideas," she went on, "was not being reciprocated."

Dr. West, of the Discovery Institute, argues that scientists have shown the same unwillingness to engage when they talk about evolution. In Kansas, he said, "there was a sort of arrogance - claiming that 'since we are the majority scientific view we don't owe an explanation to anyone, especially these public officials we think are stupid.'

"Well, they can have that attitude, but whether they like it or not we have public officials who are charged with making decisions," he said. "They seem to think the A.A.A.S. should just appoint a panel and replace every elected school board."

Despite their decision to stay away from Kansas, scientists continue to make the case for evolution.

For example, a number of scientists, including Dr. Miller, plan to testify in a case in Dover, Pa., where teachers were directed to instruct that intelligent design was a scientific alternative to evolution. "In a court of law, you have standards, rules and laws you are interpreting," Dr. Scott said, in explaining why scientists are taking part in this case. "In Kansas, it was a free-for-all."

Earlier this month, the National Academy of Sciences started a Web site (nationalacademies.org/evolution) with information about evolution and assurances that no credible scientific challenge to evolutionary theory has been raised. The American Association for the Advancement of Science (aaas.org, click on "evolution resources") and other organizations maintain similar sites.

Dr. Leshner wrote an opinion article about the evolution issue that ran in The Kansas City Star before the hearings were held this spring. The essay dealt with one of the powerful issues underlying the debate about evolution: whether science and religious faith can coexist.

It is not surprising that defenders of evolution are staying away from the hearings, he wrote, "since it's a debate that can't be won."

"After all, interpretations of Genesis are a matter of faith, not facts," he wrote. But faith and facts "should not be pitted against each other; the theory of evolution does not, in fact, conflict with the religious views of most Jewish, Christian, Muslim, Buddhist or Hindu followers."

But some scientists have made the point that it is difficult to make the case for evolution at a time when many Americans view it as an assault by the secular elite on the values of God-fearing people.

"The creation and evolution issue is not just about science," Dr. Scott said. "The science is necessary but not sufficient. It is ultimately and predominantly a political and cultural kind of issue rather than a scientific issue."

Now that the panel that conducted the hearings has recommended that challenges to evolution be taught in Kansas, "we may appear to have at least temporarily lost the battle," Dr. Leshner said. "But we have not fallen prey to allowing them to redefine science, and that's the core issue."

He added: "Evolution is not the only issue at stake. The very definition of science is at stake."