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Sally Lehrman

Understanding evolution is crucial to debate

RESIDENTS of Massachusetts might feel safe from the clashes over teaching evolution in school districts across the country. In this state, home to so many great universities, one wouldn't expect anything less than a top-notch science curriculum. In fact, Massachusetts students are supposed to begin learning about evolution and have access to impressive materials before they even reach second grade.

But that doesn't let parents or anyone else off the hook. A well-thought-out curriculum in science does not guarantee that evolution will be taught in all its glory -- or even coherently.

Darwin's brilliant theory, a powerful and central concept in biology, offers a path toward understanding everything else: the history of our universe, the world we inhabit, and ourselves. The theory turns on the idea of random variation -- mutations in our genome -- that can enable a population to adjust collectively to the environment in which it finds itself. The best-suited creatures for that situation breed successfully and so pass on these useful characteristics to offspring.

Evolution, however, has never been a static idea and perhaps never less so than today. Its power can't be expressed based solely on lessons from an education long past. It's hard to explain the nature of scientific inquiry -- questioning, testing, and gathering evidence, refining -- without sounding uncertain. Teachers know this. Last year, the American Association for the Advancement of Science asked teachers about their top concerns in teaching evolution. Most confessed that they didn't feel confident about their knowledge.

Worry they should. Even Massachusetts teachers licensed for biology don't have to take a course in evolution, although they must pass a test that includes questions on the topic. Furthermore, waivers from the state enable them to go outside of their licensed subjects. According to 2007 state figures, 11 percent of schools had assigned at least one-fifth of teachers outside of their expertise. Meanwhile, fueled in large part by molecular biology, the science itself has been powering ahead.

Data pouring out of genetic research has challenged some of scientists' assumptions about the multibranched tree of life and offered new insight on the basic tools for living that all species share. While geneticists until recently thought that random mutations in the genes drove adaptation, they are now cracking windows onto processes outside of the DNA that can change gene function for generations. A grandmother's diet, even a parent's nurturing, may influence evolution's course.

As evolutionary science accelerates, however, antievolutionists are pushing back -- and exploiting the questions that recent discoveries have raised. A new high-school textbook from the Discovery Institute, "Explore Evolution," claims to teach students critical thinking but instead uses pseudoscience to attack Darwin's theories. The National Center for Science Education, which tracks trends in schools, has compiled a frightening list of bills and local proposals intended to open the door for creationist teaching in science education. In a survey published in Science magazine last year, 39 percent of American adults flat-out rejected the concept of evolution.

Even a great curriculum doesn't necessarily mean an individual teacher is doing a good job. Across the country, school boards and instructors contend with pressure to adopt books or offer supplements that "balance" biology texts or "teach the controversy." The Institute for Creation Research, for one, hasn't given up on Massachusetts. An event planned for Methuen in November will teach "creation evangelism" and "scientific evidence for creation/design in nature." On the institute's website, students and teachers across the country can get inspiration and tools to challenge an evolution-based curriculum.

Some teachers assign their evolution module a slot at the end of the year, then run out of time. Some speed right through it. When confronted with students' probing questions, the AAAS discovered, teachers find themselves at a loss. "The state standards say nothing about what goes on in the classroom," points out Louise Mead, education project director for NCSE.

As one of their complaints, intelligent design proponents claim that schools should do a better job of explaining evolution. They may very well be right. While people who believe in the scientific method do not accept the antievolution lobby's claim of "irreducible complexity," are they prepared with a coherent response? They might say "survival of the fittest" with conviction but only have a hazy recollection of terms like "descent with modification," "natural selection," and even "mutation."

And unfortunately, those Darwin fish stickers don't come with an instruction manual.

Sally Lehrman reports on health and science for Scientific American, the radio documentary series "The DNA Files," and other media.