Harrisburg, Pa. ? A textbook advocating the concept of “intelligent design” as an alternative to evolution in high school science classes was written originally as a biblically based creationist text, a philosophy professor testified Wednesday in a federal trial over the teaching of evolution.

Barbara Forrest, who reviewed early drafts of the book, “Of Pandas and People,” said the term “creationism” was later replaced by “intelligent design” when the book’s first edition was published in 1989.

“My conclusion is that (creationism and intelligent design) are interchangeable, that they are virtually synonymous,” said Forrest, who teaches at Southeastern Louisiana University. She was the first witness called by the plaintiffs in the second week of this closely watched trial in the U.S. District Court for the Middle District of Pennsylvania.

The book, published by the Texas-based Foundation for Thought and Ethics, was originally titled “Biology and Creation” in a 1986 draft. But its authors, Dean Kenyon and Perceval Davis, shifted to intelligent design after a U.S. Supreme Court ruling in 1987 banned the teaching of creationism in public schools, Forrest said.

A group of parents in Dover, Pa., sued the school board after it approved a policy last year requiring that a statement be read in high school biology classes promoting intelligent design as an alternative to Darwin’s theory of evolution. The statement also directed students to “Of Pandas and People” if they wanted to learn more about intelligent design.