For more than a century, scientists have overwhelmingly accepted the theory of evolution. As recently as the 1960s, however, teaching about the theory in schools was a crime in several states. Even after the U.S. Supreme Court overturned such laws in 1968, resistance continued. People offended or frightened by the notion of natural selection demanded the teaching of what they called "creation science," a thinly disguised version of the Bible's Genesis story with little or no grounding in science. That, too, was found to be unconstitutional, an attempt to preach one view of religion to a captive audience of many...