DOVER, Pa. -- Students at Dover High School in York County heard a statement about intelligent design during high school biology lessons Tuesday.

The district's superintendent read the short statement, which amounts to only a few minutes.

"Because Darwin's theory is a theory, it continues to be tested as new evidence is discovered. The theory is not a fact. Gaps in the theory exist for which there is no evidence," part of the statement says. "With respect to any theory, students are encouraged to keep an open mind. The school leaves the discussion of the origins of life to individual students and their families."

Opponents say intelligent design amounts to teaching religion in science class.

A letter was sent home to students last week, giving them the option of having their children excused while the statement is read. The superintendent's office said 14 parents chose to have their students removed from class.

Three members of the Dover School Board have resigned as a result of the decision to have intelligent design taught in science classes, and a federal lawsuit has been filed by 11 parents and the American Civil Liberties Union.

"I am surprised that they didn't change their minds to get out of the trouble that they are in," said Angie Yingling, a school board member who resigned.

An attorney for the school district said teachers are excused from reading the statement because of the pending federal lawsuit over the policy.

Members of the scientific community are weighing in, and saying intelligent design is simply not science.

Dozens of science professors from nearby universities are now speaking out. They said intelligent design doesn't belong in science class.

As a professor of biology at York College, Karl Kleiner studies the natural world. Kleiner pays close attention to how and why things work. In his opinion, teaching intelligent design in high school science class does not work.

"We're looking at an issue, a debate -- I hate to call it a debate -- between what is science and what is faith, religion or philosophy," Kleiner said.

Kleiner said science is based on observations that are rooted in fact, things on which the scientific community can agree.

"Intelligent design leaves it up to some sort of supernatural force. That's not what science is about," Kleiner said.

Supporters of intelligent design argue that evolution is a theory.

Kleiner said theories are part of the scientific process and that Darwin based his theory on observations.

"A theory is not just a guess, not just a hunch. It is something that best explains existing facts about what we see in the world around us," Kleiner said.

Kleiner and his colleagues feel so strongly that intelligent design should not be part of the curriculum at Dover, they wrote a letter to the district.

"We just felt to introduce intelligent design as science would be doing the students an injustice in terms of science curriculum," Kleiner said.

Kleiner said the place to teach intelligent design is in philosophy or religion class, but not in science.