Nearly 30 years of teaching evolution in Kansas has taught Brad Williamson to expect resistance, but even this veteran of the trenches now has his work cut out for him when students raise their hands.
That's because critics of Charles Darwin's theory of natural selection are equipping families with books, DVDs, and a list of "10 questions to ask your biology teacher."
The intent is to plant seeds of doubt in the minds of students as to the veracity of Darwin's theory of evolution.
The result is a climate that makes biology class tougher to teach. Some teachers say class time is now wasted on questions that are not science-based. Others say the increasingly charged atmosphere has simply forced them to work harder to find ways to skirt controversy.
On Thursday, the Science Hearings Committee of the Kansas State Board of Education begins hearings to reopen questions on the teaching of evolution in state schools.
The Kansas board has a famously zigzag record with respect to evolution. In 1999, it acted to remove most references to evolution from the state's science standards. The next year, a new - and less conservative - board reaffirmed evolution as a key concept that Kansas students must learn.
Now, however, conservatives are in the majority on the board again and have raised the question of whether science classes in Kansas schools need to include more information about alternatives to Darwin's theory.
But those alternatives, some science teachers report, are already making their way into the classroom - by way of their students.
In a certain sense, stiff resistance on the part of some US students to the theory of evolution should come as no surprise.
Even after decades of debate, Americans remain deeply ambivalent about the notion that the theory of natural selection can explain creation and its genesis.
A Gallup poll late last year showed that only 28 percent of Americans accept the theory of evolution, while 48 percent adhere to creationism - the belief that an intelligent being is responsible for the creation of the earth and its inhabitants.
But if reluctance to accept evolution is not new, the ways in which students are resisting its teachings are changing.
"The argument was always in the past the monkey-ancestor deal," says Mr. Williamson, who teaches at Olathe East High School. "Today there are many more arguments that kids bring to class, a whole fleet of arguments, and they're all drawn out of the efforts by different groups, like the intelligent design [proponents]."
It creates an uncomfortable atmosphere in the classroom, Williamson says - one that he doesn't like. "I don't want to ever be in a confrontational mode with those kids ... I find it disheartening as a teacher."
Williamson and his Kansas colleagues aren't alone. An informal survey released in April from the National Science Teachers Association found that 31 percent of the 1,050 respondents said they feel pressure to include "creationism, intelligent design, or other nonscientific alternatives to evolution in their science classroom."
These findings confirm the experience of Gerry Wheeler, the group's executive director, who says that about half the teachers he talks to tell him they feel ideological pressure when they teach evolution.
And according to the survey, while 20 percent of the teachers say the pressure comes from parents, 22 percent say it comes primarily from students.
In this climate, science teachers say they must find new methods to defuse what has become a politically and emotionally charged atmosphere in the classroom. But in some cases doing so also means learning to handle well-organized efforts to raise doubts about Darwin's theory.
Darwin's detractors say their goal is more science, not less, in evolution discussions.
The Seattle-based Discovery Institute distributes a DVD, "Icons of Evolution," that encourages viewers to doubt Darwinian theory.
One example from related promotional literature: "Why don't textbooks discuss the 'Cambrian explosion,' in which all major animal groups appear together in the fossil record fully formed instead of branching from a common ancestor - thus contradicting the evolutionary tree of life?"
Such questions too often get routinely dismissed from the classroom, says senior fellow John West, adding that teachers who advance such questions can be rebuked - or worse.
"Teachers should not be pressured or intimidated," says Mr. West, "but what about all the teachers who are being intimidated and in some cases losing their jobs because they simply want to present a few scientific criticisms of Darwin's theory?"
But Mr. Wheeler says the criticisms West raises lack empirical evidence and don't belong in the science classroom.
"The questions scientists are wrestling with are not the same ones these people are claiming to be wrestling with," Wheeler says. "It's an effort to sabotage quality science education. There is a well-funded effort to get religion into the science classroom [through strategic questioning], and that's not fair to our students."
Teaching that humans evolved by a process of natural selection has long stirred passionate debate, captured most famously in the Tennessee v. John Scopes trial of 1925.
Today, even as Kansas braces for another review of the question, parents in Dover, Pa., are suing their local school board for requiring last year that evolution be taught alongside the theory that humankind owes its origins to an "intelligent designer."
In this charged atmosphere, teachers who have experienced pressure are sometimes hesitant to discuss it for fear of stirring a local hornets' nest. One Oklahoma teacher, for instance, canceled his plans to be interviewed for this story, saying, "The school would like to avoid any media, good or bad, on such an emotionally charged subject."
Others believe they've learned how to successfully navigate units on evolution.
In the mountain town of Bancroft, Idaho (pop. 460), Ralph Peterson teaches all the science classes at North Gem High School. Most of his students are Mormons, as is he.
When teaching evolution at school, he says, he sticks to a clear but simple divide between religion and science. "I teach the limits of science," Mr. Peterson says. "Science does not discuss the existence of God because that's outside the realm of science." He says he gets virtually no resistance from his students when he approaches the topic this way.
In Skokie, Ill., Lisa Nimz faces a more religiously diverse classroom and a different kind of challenge. A teaching colleague, whom she respects and doesn't want to offend, is an evolution critic and is often in her classroom when the subject is taught.
In deference to her colleague's beliefs, she says she now introduces the topic of evolution with a disclaimer.
"I preface it with this idea, that I am not a spiritual provider and would never try to be," Ms. Nimz says. "And so I am trying not ... to feel any disrespect for their religion. And I think she feels that she can live with that."
The path has been a rougher one for John Wachholz, a biology teacher at Salina (Kansas) High School Central. When evolution comes up, students tune out: "They'll put their heads on their desks and pretend they don't hear a word you say."
To show he's not an enemy of faith, he sometimes tells them he's a choir member and the son of a Lutheran pastor. But resistance is nevertheless getting stronger as he prepares to retire this spring.
"I see the same thing I saw five years ago, except now students think they're informed without having ever really read anything" on evolution or intelligent design, Mr. Wachholz says. "Because it's been discussed in the home and other places, they think they know, [and] they're more outspoken.... They'll say, 'I don't believe a word you're saying.' "
As teachers struggle to fend off strategic questions - which some believe are intended to cloak evolution in a cloud of doubt - critics of Darwin's theory sense an irony of history. In their view, those who once championed teacher John Scopes's right to question religious dogma are now unwilling to let a new set of established ideas be challenged.
"What you have is the Scopes trial turned on its head because you have school boards saying you can't say anything critical about Darwin," says Discovery Institute president Bruce Chapman on the "Icons of Evolution" DVD.
But to many teachers, "teaching the controversy" means letting ideologues manufacture controversy where there is none. And that, they say, could set a disastrous precedent in education.
"In some ways I think civilization is at stake because it's about how we view our world," Nimz says. The Salem Witch Trials of 1692, for example, were possible, she says, because evidence wasn't necessary to guide a course of action.
"When there's no empirical evidence, some very serious things can happen," she says. "If we can't look around at what is really there and try to put something logical and intelligent together from that without our fears getting in the way, then I think that we're doomed."
Critics of evolution are supplying students with prepared questions on such topics as:
• The origins of life. Why do textbooks claim that the 1953 Miller-Urey experiment shows how life's building blocks may have formed on Earth - when conditions on the early Earth were probably nothing like those used in the experiment, and the origin of life remains a mystery?
• Darwin's tree of life. Why don't textbooks discuss the "Cambrian explosion," in which all major animal groups appear together in the fossil record fully formed instead of branching from a common ancestor - thus contradicting the evolutionary tree of life?
• Vertebrate embryos. Why do textbooks use drawings of similarities in vertebrate embryos as evidence for common ancestry - even though biologists have known for over a century that vertebrate embryos are not most similar in their early stages, and the drawings are faked?
• The archaeopteryx. Why do textbooks portray this fossil as the missing link between dinosaurs and modern birds - even though modern birds are probably not descended from it, and its supposed ancestors do not appear until millions of years after it?
• Peppered moths. Why do textbooks use pictures of peppered moths camouflaged on tree trunks as evidence for natural selection - when biologists have known since the 1980s that the moths don't normally rest on tree trunks, and all the pictures have been staged?
• Darwin's finches. Why do textbooks claim that beak changes in Galapagos finches during a severe drought can explain the origin of species by natural selection - even though the changes were reversed after the drought ended, and no net evolution occurred?
• Mutant fruit flies. Why do textbooks use fruit flies with an extra pair of wings as evidence that DNA mutations can supply raw materials for evolution - even though the extra wings have no muscles and these disabled mutants cannot survive outside the laboratory?
• Human origins. Why are artists' drawings of apelike humans used to justify materialistic claims that we are just animals and our existence is a mere accident - when fossil experts cannot even agree on who our supposed ancestors were or what they looked like?
• Evolution as a fact. Why are students told that Darwin's theory of evolution is a scientific fact - even though many of its claims are based on misrepresentations of the facts?
Source: Discovery Institute