What should public schools teach about Darwin's theory? Should science educators discuss -- or not even mention -- the theory of evolution?
Many educators wish these questions would simply go away. On the one hand, if science teachers teach Darwinian evolution, many parents and religious activists will protest. On the other, if teachers present religiously based theories, civil liberties groups will threaten legal action.
Either way, educators face a no-win situation.
Little wonder, then, that many are seeking a way to finesse the issue. Georgia Schools Superintendent Kathy Cox recently tried to do this by removing the word "evolution" from the state's science standards. When this resulted in a national controversy, she wisely reversed her decision. Now the problem rests with a commission of teachers.
But what should they do? Is there any approach that will satisfy -- if not everybody -- at least most reasonable people?
Surprisingly, there is a way to teach evolution that will benefit students and satisfy all but the most extreme partisans and ideologues. Rather than ignoring the controversy (as many educators have tried to do), teachers should teach about the scientific controversy that now exists over Darwinian evolution. This is simply good education.
When credible experts disagree about a controversial subject, students should learn about the competing perspectives.
In such cases, teachers should not teach as true only one competing view -- just the Republican or just the Democratic view of the New Deal in history class, for example. Instead, teachers should describe competing views to students and explain the arguments for and against these views as made by their chief proponents. We call this "teaching the controversy."
But is there really a scientific, as opposed to just a cultural or religious, controversy over evolution?
In fact, there are several scientific controversies about key aspects of evolutionary theory.
First, some scientists doubt the idea that all organisms have evolved from a single common ancestor. Why? Fossil studies reveal a "biological big bang" near the beginning of the Cambrian period (530 million years ago) when many major, separate groups of organisms, or "phyla" (including most basic body plans of modern animals), emerged suddenly without clear precursors.
Fossil finds have repeatedly confirmed a pattern of explosive appearance and prolonged stability in living forms -- not the gradual branching tree pattern implied by Darwin's common-ancestry thesis.
Support for a new theory
Other scientists doubt the creative power of the Darwinian mechanism. While many scientists accept that natural selection can produce small-scale, "micro-evolutionary" variations, many biologists now doubt that natural selection and random mutations can generate the large-scale changes necessary to produce fundamentally new living forms, such as those that arose in the Cambrian period.
Recently, more than 300 scientists, including professors from institutions such as MIT, Yale, Rice and the University of Georgia, signed a statement questioning the creative power of the selection/mutation mechanism.
Finally, some scientists doubt the Darwinian idea that living things merely "appear" designed. They favor a new theory known as "intelligent design." Design advocates, such as Lehigh University biochemist Michael Behe, martialed some intriguing new evidence in support of their theory, such as the presence of encoded information, circuits and miniature motors inside cells.
Since Darwinian evolution is still the dominant theory of biological origins, we recommend that students not be required to learn the theory of intelligent design. Nevertheless, we think they should learn about the scientific strengths and weaknesses of modern Darwinism. Obviously, teachers should also be free to discuss new evidence-based theories, including Behe's design theory.
Consider all sides
There are many reasons to adopt this approach. First, constitutional law permits "teaching the controversy" about scientific theories of origins. In the controlling Edwards v. Aguillard case, the Supreme Court made clear that state legislatures (and by extension state boards) already have the right to mandate teaching scientific critiques of prevailing theories. Interestingly, the court also determined that teachers have the right to teach students about "a variety of scientific theories about origins . . . with the clear secular intent of enhancing science education."
Second, federal education policy calls for teaching differing scientific views of this controversy. The authoritative report language accompanying the No Child Left Behind act states that "where topics are taught that may generate controversy (such as biological evolution), the curriculum should help students to understand the full range of views that exist."
Third, voters overwhelmingly favor this approach. In a recent national Zogby poll, 71 percent of those polled favored teaching both the evidence for and against contemporary Darwinian theory.
Finally, this approach will enhance science instruction. Teaching scientific controversies engages student interest and encourages them to do what scientists must do -- deliberate about how best to interpret evidence.
As Darwin wrote in "The Origin of Species," "a fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question."