WASHINGTON (AP) — If today's students want to understand how scientists mapped the human genetic code, they won't get much help from their high school textbooks, a group of scientists and educators said recently.
"Textbooks treat the topic piecemeal, leaving out the simple story or obscuring it with needless details," said George Nelson of the American Association for the Advancement of Science.
The group leveled its harshest critique yet of U.S. math and science lessons, giving an unsatisfactory rating to all 10 of the major high school biology textbooks it reviewed. Researchers said the books--hundreds of pages long and filled with quizzes and splashy color drawings of cells--miss the big picture.
They don't flesh out the four basic ideas driving today's research: how cells work, how matter and energy flow from one source to another, how plants and animals evolve and the molecular basis of heredity.
In addition to glossing over vital concepts to drill students on vocabulary words, the books do not encourage students to examine their ideas or relate lessons to hands-on experiments and everyday life, researchers said in the report released Tuesday.
For instance, they said, students kept busy naming the parts of cells might miss learning how cells work--and understanding how scientists could use that knowledge to search the DNA in human cells for defective genes that cause diseases.
"In a democracy, people should have a voice in making these decisions, and that should come from an informed opinion rather than just an emotional one," said Nelson, a former astronaut who now leads the group's campaign to improve science and math education.
Reacting to the report, publishers said state standards drive the content of biology lessons.
"The content of instructional materials is not determined by those who publish these materials but rather by those who use them," said Stephen Driesler, executive director of the school division of the Association of American Publishers Inc.
The books the group studied represent the most widely used of about two dozen biology texts published for millions of students in grades 9 through 12. No books were considered excellent or satisfactory.
The college and K-12 teachers and biologists who reviewed the books had no relationship with the publishers. The Carnegie Foundation financed the project.
Although publishers depend on local school boards to buy their materials, they have not shied away from politically sensitive topics such as evolution, which is dismissed by creationists, who favor a Bible-based view of Earth's formation.
"Kids are not going to learn much biology but it's not because books are watered down for political reasons," Nelson said.
Though some books scored well in specific categories, none was good at building on what pupils already know or correcting misconceptions, Nelson said.
Due to misinformation from peers, families or even a poor teacher, a child might think giraffes developed longer necks from reaching for branches. Good biology lessons, Nelson said, would help that student deduce that animals are randomly born with traits, such as longer necks to reach for high branches, that make them more likely to survive and have offspring.
Charts and more details about the evaluation of biology textbooks can be found online at http://project2061.aaas.org