The fights in scattered school districts over whether to teach creationism or its rival, called intelligent design, as alternatives to Darwin's theory of evolution may be obscuring a deeper problem: the tendency of many districts to duck controversy by avoiding or soft-pedaling any teaching of evolution at all. Nobody knows the extent of the problem, but an article by Cornelia Dean in Science Times on Tuesday cites ample evidence that even when evolution is theoretically part of the curriculum, it is often ignored or played down in the classroom.

Some teachers duck the subject, lest they get into trouble with school administrators or fundamentalist parents. Others assign a chapter on evolution for reading but avoid any discussion in the classroom. Still others discuss evolutionary concepts without ever mentioning "the E word" to avoid arousing controversy.

Although most state curriculum standards mandate that evolution be taught, and standardized tests typically include questions on evolution, some teachers apparently assume that evolution is a small enough part of the curriculum that their students can get by without mastering the subject. Those students remain ignorant of one of the bedrock theories underlying modern biology.

In some areas of the country, many biology teachers are themselves believers in creationism. A 1998 doctoral dissertation found that 24 percent of the biology teachers sampled in Louisiana said that creationism had a scientific foundation and that 17 percent were not sure. Several surveys have shown that many teachers give at least some instructional time to creationism or intelligent design out of a sense of fairness.

That serves the students and the nation poorly as they enter an age likely to be dominated by biology.