The battle over attempts to introduce a version of creationism into the curriculum of American schools has become focused on a small town in Pennsylvania.
Biology teachers at a high school in Dover have rejected the instructions of local officials to read a statement in class today questioning the theory of evolution.
They had been ordered by the town's elected school board to preface their usual class on evolution with a statement, saying "Darwin's Theory is a theory ... not a fact. Gaps in the theory exist for which there is no evidence."
As an alternative, the statement mentions "intelligent design," an updated form of creationism which argues that life on earth is too complex to have developed at random.
The teachers asked to opt out of making the statement and it will be read instead by a school administrator before a biology class early next week.
The Dover school board's actions make the town the first in the US to promote "intelligent design" in competition to evolution. It has become the subject of a lawsuit by a group of parents that has pitted the Christian right against the American Civil Liberties Union (ACLU).
The case is due to be heard in the next few months.
"Intelligent design is more than an attack on evolution. What these folks are proposing is to allow faith and miracles and supernatural creators to be considered as science," said Witold Walczak, the ACLU's legal director in Pennsylvania.
A US Supreme Court decision in 1987 banned the teaching of creationism on the grounds that it would violate the separation of church and state.
The Dover school board decision is one of a series of signs that the movement is making a comeback.
Walczak predicted that it would gather steam as Christian conservatives drew inspiration from President George W. Bush's re-election.
A CBS/New York Times poll at the time of the election found 55 percent of Americans believed God created humans in their present form, 27 percent believed in evolution guided by God and only 13 percent believed God was not involved in human evolution.
Sixty-five percent backed teaching creationism alongside evolution.
The Dover school board and its supporters argue that "intelligent design" is not covered by the 1987 Supreme Court decision because it is not inherently religious, but a scientific challenge to Darwinism.
"Religion has nothing to do with intelligent design," said Carl Jarboe, a former chemistry professor and a supporter of the Dover school board.
"I am alleging there is not one piece of scientific evidence that supports evolution," he said.