AUSTIN, Texas — Religious leaders, scientists and parents launched a campaign yesterday that they say is an effort to protect the accurate teaching of evolution in high school biology textbooks.

"Evolution is the most crucial concept we teach in biology. It is the cornerstone for understanding the living world," said Austin biology teacher Amanda Walker. "Evolution is informing medicine on such diseases as prostate cancer, heart disease, SARS and AIDS, and many others."

The campaign, called Stand Up For Science, was unveiled as the state Board of Education prepares to adopt new biology textbooks this fall.

The evolution proponents criticized what they say are attempts to teach creationist theories and said creationism isn't used as a basis in science or medical literature.

Other groups, including the Discovery Institute, say they just want to ensure that scientific weaknesses of evolution, or Darwinism, are presented to Texas students.

"All Discovery Institute has ever advocated is that textbooks should fix embarrassing factual errors and tell students about the scientific weaknesses of neo-Darwinism as well as its strengths," said John G. West, associate director of the Discovery Institute's Center for Science & Culture. "This is fully in accord with Texas law, which says students should know the scientific evidence that both supports and shows the weaknesses of existing scientific theories."

The Discovery Institute is a Seattle-based think-tank that critics claim is leading a push to teach alternatives to evolution in public schools. The institute's literature mentions "intelligent design" — a belief that species did not evolve by natural selection but instead progressed according to a plan or design.

In an Aug. 19 open letter to the state Board of Education, distributed by the Discovery Institute, 24 professors wrote that "in recent years, a growing number of scientists have raised significant issues that challenge various aspects of neo-Darwinian theory. Thus, we think the best science education will present students with both 'the strengths and weaknesses' of neo-Darwinian theory."

Critics say "intelligent design" is a dressed-up version of creationism, which the U.S. Supreme Court has prohibited from public schools as a violation of the separation of church and state. (The Supreme Court in 1987 in Edwards v. Aguillard said that schools cannot require equal time for creationism if evolution is taught.)

Larry Bethune, chairman of the Texas Freedom Network, said that undermining the study of science threatens Texas children's ability to compete for jobs and the state's ability to compete for business. The Texas Freedom Network is an organization that calls itself a watchdog of the religious right.

"The choice of the state Board of Education is not between religion and science, but a decision about which will be taught in our science classrooms," said Bethune, also a Baptist pastor.

The Board of Education has no say over textbook content, but the board can reject books because of errors or failure to follow the state curriculum.

The board is to make its final decision on the biology textbooks in November. Another public hearing is planned for Sept. 10. Publishers must submit final changes by Oct. 3.