HARRISBURG, Pa., Sept. 27 - Science teachers at the high school in Dover repeatedly resisted the school board's efforts to force them to teach creationism on equal footing with evolution in biology class, according to a former teacher who is among those challenging the board in a landmark trial.

The conflict in Dover grew so heated that in public meetings board members called opponents "atheists," threatened to fire the science teachers and invoked Jesus' crucifixion as a reason to change the curriculum, two witnesses testified on Tuesday. "We would repeatedly tell them, 'We're not going to balance evolution with creationism. It's an inappropriate request,' " said Bryan Rehm, who once taught physics in Dover and is one of 11 plaintiffs in the suit.

The trial here is the first in the nation to test whether public schools can teach intelligent design - the notion that living organisms are so complex they must have been designed by a higher intelligence - or whether the theory is simply a fig leaf for creationism.

Outside the courtroom on Tuesday afternoon, Alan Bonsell, a board member who the plaintiffs said was leading the charge against evolution in the science curriculum, said the board wanted students to learn about competing theories only because it was "good education."

The board ultimately abandoned the equal time idea, stopped using the term "creationism," and instead required that ninth graders listen to a brief statement encouraging them to learn about intelligent design as an alternative to evolution. "We are not teaching intelligent design," Mr. Bonsell said. "I've said that a million times and the news media just doesn't get it. I challenge everybody to read the statement and show me what was religious in the statement."

But Aralene Callahan, a former board member, testified that Mr. Bonsell, the chairman of the curriculum committee, said at a school board retreat in 2003 that he did not believe in evolution and wanted "50-50" treatment in biology class for creationism and evolution. The board wanted the science teachers to use a textbook that promotes intelligent design, "Of Pandas and People," but the teachers balked at that too, Mr. Rehm said.

For about a year, Mrs. Callahan said, the school board refused to order new biology textbooks. Mrs. Callahan said that when she protested the delay at a meeting, another board member, Bill Buckingham, responded that the biology textbook was "laced with Darwinism." The textbook he was referring to was "Biology." One of the book's authors, Kenneth Miller, a cell biologist at Brown University, was in court here on Monday and Tuesday as the first witness against intelligent design.

At a board meeting in June 2004, the plaintiffs say that Mr. Buckingham declared from the podium: "Two thousand years ago, someone died on a cross. Can't someone take a stand for him?" Two newspapers in York reported the remark. But the defendants say Mr. Buckingham was misquoted. The head of the school board, Sheila Harkins, said on Tuesday that Mr. Buckingham did say it, but at a meeting nine months earlier while the board considered a resolution to support the words "under God" in the Pledge of Allegiance.

The plaintiffs believe the reference to the crucifixion is so crucial to establishing the board's religious motivation that they have subpoenaed the two York newspaper reporters, who have refused to testify.