The state school board Tuesday approved a lesson plan for teaching evolution that includes what critics contend is a religious theory "cloaked as science."

Supporters argued the lesson plan offers scientific ways to analyze evolution, but scientific groups objected and critics said they expected a lawsuit.

After six hours of testimony, the board voted 13-5 in favor of "Critical Analysis of Evolution," an optional set of lessons for schools to use in teaching science for a new graduation test.

Critics say the lessons contain elements of a theory called intelligent design (search), which states a higher power must have been involved in the creation of life.

"I am convinced this is a religious effort cloaked as science," said board member Robin Hovis.

At issue is 22 pages out of more than 500 that schools can use to teach new science standards approved last year for all grades. No student will be tested on intelligent design, said board president Jennifer Sheets.

The vote was applauded by the Seattle-based Discovery Institute (search), which supports scientists studying intelligent design theory, and says states should teach both evolution and scientific criticism of evolutionary theory.

The vote "is a significant victory for students and their academic freedom to study all sides of current scientific debates over evolutionary theory," said Bruce Chapman, Discovery Institute president.

Board member Sam Schloemer complained the lessons "further erode the status and the value of Ohio's public education system because it is without scientific evidence," he said.

Several scientific organizations, including the National Academy of Sciences (search), are opposed to the lessons.

Others predicted the plan would be challenged in court.

"They're standing in line — high school teachers, board members, parents, the students themselves," said Patricia Princehouse, a Case Western Reserve University (search) philosophy professor who has led lobbying efforts against the lessons.

Board member James Turner, appointed to the board by Gov. Bob Taft, said he was impressed by the number of scientists in favor of the lessons, arguing opponents were "allowing their fear of what this lesson could lead to" to reflect their views.

The board should rely on the guidance of evolutionary biologists with experience studying evolution, argued Stephen Weeks, a University of Akron biologist.

"If someone's an expert and they're telling you they need a brain tumor removed in a certain way, that's weighted more than your mechanic's opinion," Weeks said.

The state school board a lesson plan on evolution Tuesday that critics say tries to cloak religion in science. Supporters say it offers scientific ways to analyze evolution theory.