More than 70 years after John Scopes was convicted of violating a state law by teaching his high school class that humans were descended from apes, the debate over the teaching of evolution is back in the news.
Creationists in the Atlanta area have been particularly successful in the last few months. Cobb County recently ordered a special edition of an elementary school textbook that eliminated the chapter on the origins of the universe, and Clayton County inserted a "disclaimer" in science textbooks calling evolution "a controversial theory that some scientists present as a scientific explanation for the origin of living things." Georgia School Superintendent Linda Schrenko has been a strong advocate of teaching creationism, and in recent months at least three other Georgia counties have considered creationist changes to their science curricula.
Georgia is not alone. Alabama adopted textbook disclaimers statewide last year, and the legislature in Scopes' home state of Tennessee debated a bill in March that would have authorized the firing of any teacher who taught evolution as a "fact." Ohio is presently considering creationist legislation, and in recent years, similar proposals have been discussed, and in some cases adopted, in school districts in California, Illinois, Washington, Louisiana and other states.
Recent creationist initiatives have taken one of two tacks: either removing evolution from the curriculum, as in Cobb County, or attempting to undermine students' confidence in the scientific validity of evolution by inserting disclaimers into textbooks that make reference to it. Hemmed in by an increasingly restrictive set of court decisions, creationists have shifted tactics several times in recent decades. The law under which Scopes was prosecuted, like other early creationist legislation, criminalized the teaching of evolution. Such laws were declared unconstitutional by a 1968 Supreme Court decision, Epperson v. Arkansas. Blocked by the Epperson decision from prosecuting teachers who presented views that conflicted with the biblical account of life's origins, supporters of creationist teaching adopted a newfound spirit of inclusiveness.
Evolution may be taught, they argued, but it is only fair to present students with a diversity of ideas about the origin and history of life. So-called "scientific creationism" dressed religious ideas in scientific language and was proposed as a legitimate alternative "theory" that should be taught side by side with evolution. Laws requiring such "balanced" instruction in both evolution and creationism were adopted in a number of states. However, the Supreme Court ruled in the 1987 case Edwards v. Aguillard that such laws were themselves unconstitutional, finding that "creation science" was "inherently religious" rather than scientific, and could not be "promoted" in public school science classes.
Barred from these routes of attack, creationists have resorted to raising questions about the scientific status of evolution. The textbook disclaimers recently adopted in Alabama and in Clayton County state that there is scientific controversy about whether evolution accounts for the development of life on earth. Stating that evolution is a "theory" rather than a directly observed "fact," these disclaimers attempt to cast doubt on its validity, playing on the colloquial use of the word "theory" to mean "hunch" or "idea" or even "guess." The contents of these disclaimers mislead students about the nature of the scientific process by suggesting that a scientific theory is somehow a second-rate idea, rather than a comprehensive and testable explanation of a variety of data (in the case of evolutionary theory, an explanation that has been repeatedly tested and very well supported by the evidence). The disclaimers' statement that scientists are divided over the validity of evolution is simply false.
As creationists attempt to undermine students' confidence in the evolutionary principles presented in their textbooks, a more insidious problem also is emerging. In an effort to avoid offending students or creating controversy, science teachers in secondary schools and even some universities are avoiding the subject of evolution altogether. Sometimes this happens because an individual teacher simply decides to skip the topic. Cobb County's decision to delete the subject of the formation of the earth from its elementary school textbook is an example of a similar trend on a district-wide level.
As teachers, researchers and citizens, we have an important stake in the outcome of these controversies. Students who are misinformed--or worse, not informed at all--about the central idea underlying modern biology will be at a disadvantage as they continue in science education. Blurring the distinction between scientific theories, which are judged by their ability to explain the observed data and to survive repeated tests, and religious doctrines, whose acceptance depends on faith, further misleads students about the nature of science and the role of evidence.
The more extreme creationist proposals, such as the bill debated recently in Tennessee, also are direct threats to academic freedom. Scientists have been active in promoting the teaching of evolution and defending it against creationist attacks. A group of scientists at the University of Georgia has been deeply involved in the overhaul of the curriculum in Oconee County schools near Athens, where one of their major roles has been to defend the curriculum against creationist attempts to change it. Fifty Emory scientists wrote to Superintendent Schrenko this spring when she announced her desire to change the state's long-standing policy of opposition to the teaching of creationism.
Although the evolution-creation debate is often presented as one between science and religion, many major religious groups openly support the teaching of evolution in public schools and oppose the injection of religious ideas into science classes. Indeed, during a trial about creationism in Arkansas in 1981, for example, the supporters of the pro-evolution, anti-creationist side included leaders of the United Methodist, Presbyterian, African Methodist Episcopal, Roman Catholic and Episcopal churches.
Whatever one's religious views, the continued freedom to hold and espouse those views depends on maintaining constitutional protections against the state's meddling in religion. Creationists' attempts to present their religious views as science in the public schools are a direct threat to those protections.
Marc Lipsitch is a postdoctoral researcher in the biology department.