Louisville, Kentucky - Home-school mom Susan Mule wishes she hadn't taken a friend's advice and tried a textbook from a popular Christian publisher for her 10-year-old's biology lessons.
Mule's precocious daughter Elizabeth excels at science and has been studying tarantulas since she was 5. But she watched Elizabeth's excitement turn to confusion when they reached the evolution section of the book from Apologia Educational Ministries, which disputed Charles Darwin's theory.
"I thought she was going to have a coronary," Mule said of her daughter, who is now 16 and taking college courses in Houston. "She's like, 'This is not true!'"
Christian-based materials dominate a growing home-school education market that encompasses more than 1.5 million students in the U.S. And for most home-school parents, a Bible-based version of the Earth's creation is exactly what they want. Federal statistics from 2007 show 83 percent of home-schooling parents want to give their children "religious or moral instruction."
"The majority of home-schoolers self-identify as evangelical Christians," said Ian Slatter, a spokesman for the Home School Legal Defense Association. "Most home-schoolers will definitely have a sort of creationist component to their home-school program."
Those who don't, however, often feel isolated and frustrated from trying to find a textbook that fits their beliefs.
Two of the best-selling biology textbooks stack the deck against evolution, said some science educators who reviewed sections of the books at the request of The Associated Press.
"I feel fairly strongly about this. These books are promulgating lies to kids," said Jerry Coyne, an ecology and evolution professor at the University of Chicago.
The textbook publishers defend their books as well-rounded lessons on evolution and its shortcomings. One of the books doesn't attempt to mask disdain for Darwin and evolutionary science.
"Those who do not believe that the Bible is the inspired, inerrant Word of God will find many points in this book puzzling," says the introduction to "Biology: Third Edition" from Bob Jones University Press. "This book was not written for them."
The textbook delivers a religious ultimatum to young readers and parents, warning in its "History of Life" chapter that a "Christian worldview ... is the only correct view of reality; anyone who rejects it will not only fail to reach heaven but also fail to see the world as it truly is."
When the AP asked about that passage, university spokesman Brian Scoles said the sentence made it into the book because of an editing error and will be removed from future editions.
The size of the business of home-school texts isn't clear because the textbook industry is fragmented and privately held publishers don't give out sales numbers. Slatter said home-school material sales reach about $1 billion annually in the U.S.
Publishers are well aware of the market, said Jay Wile, a former chemistry professor in Indianapolis who helped launch the Apologia curriculum in the early 1990s.
"If I'm planning to write a curriculum, and I want to write it in a way that will appeal to home-schoolers, I'm going to at least find out what my demographic is," Wile said.
In Kentucky, Lexington home-schooler Mia Perry remembers feeling disheartened while flipping through a home-school curriculum catalog and finding so many religious-themed textbooks.
"We're not religious home-schoolers, and there's somewhat of a feeling of being outnumbered," said Perry, who has home-schooled three of her four children after removing her oldest child from a public school because of a health condition.
Perry said she cobbled together her own curriculum after some mainstream publishers told her they would not sell directly to home-schooling parents.
Wendy Womack, another Lexington home-school mother, said the only scientifically credible curriculum she's found is from the Maryland-based Calvert School, which has been selling study-at-home materials for more than 100 years.
Apologia and Bob Jones University Press say their science books sell well. Apologia's "Exploring Creation" biology textbook retails for $65, while Bob Jones' "Biology" Third Edition lists at $52.
Coyne and Virginia Tech biology professor Duncan Porter reviewed excerpts from the Apologia and Bob Jones biology textbooks, which are equivalent to ninth- and 10th-grade biology lessons. Porter said he would give the books an F.
"If this is the way kids are home-schooled then they're being shortchanged, both rationally and in terms of biology," Coyne said. He argued that the books may steer students away from careers in biology or the study of the history of the earth.
Wile countered that Coyne "feels compelled to lie in order to prop up a failing hypothesis (evolution). We definitely do not lie to the students. We tell them the facts that people like Dr. Coyne would prefer to cover up."
Adam Brown's parents say their 16-year-old son's belief in the Bible's creation story isn't deterring him from pursuing a career in marine biology. His parents, Ken and Polly Brown, taught him at their Cedar Grove, Ind., home using the Apologia curriculum and other science texts.
Polly Brown said her son would gladly take college courses that include evolution, and he'll be able to provide the expected answers even though he disagrees.
"He probably knows it better than the kids who have been taught evolution all through public school," Polly Brown said. "But that is in order for him to understand both sides of that argument because he will face it throughout his higher education."