More than any other event, the 1925 trial in Dayton, Tenn., at which the schoolteacher John Scopes was fined $100 for teaching Darwinian theory in violation of a newly enacted state law, has shaped contemporary American public thinking about the evolution-versus-Genesis debate. And it's amazing how much most people assume about the trial is wrong.

The Scopes trial is best known for pitting William Jennings Bryan, a populist orator and evangelist who was roughly the Billy Graham of his day, against fabled defense attorney Clarence Darrow. Bryan argued that Tennessee's anti-Darwin law should be upheld; Darrow argued for freedom of speech. Scopes was convicted, but his fine was overturned on appeal. Anti-evolution laws were sufficiently discredited by the trial that most were repealed; in 1968, in Epperson v. Arkansas, the Supreme Court ruled that laws against teaching evolution were unconstitutional. Today in journalism and public speaking, the phrase "Scopes monkey trial" is commonly employed as a shorthand way of saying that religion is anti-scientific; in popular culture, the notion has risen that at the Scopes trial, Bible-beating zealots ran amok. But the actualities of the trial do not support this view.

The first point to know is that when Darwin initially aired his thesis, with the 1859 publication of "Origin of Species and the Descent of Man," it sparked a science versus religion controversy in England but not in the United States. Most American faith figures initially did not react against Darwin. Asa Gray, a botanist and devout Christian who was one of Harvard's best-known scientists in the late 19th century, championed Darwin in the United States and wrote that evolution did not conflict with faith; this view was widely accepted.

When "The Fundamentals," a popular series of tracts that sparked the modern American fundamentalist movement, began publication in 1909, most of these works spoke kindly of Darwin, suggesting that evolution helped people understand God's process of creation.

Only in the 1920s did Darwin and religion come into regular conflict in the United States. There were several reasons. One was that paleontologists were beginning to accumulate evidence that human beings descended from earlier primates. Scientific findings of "cave men" were banner headline stories of the time, and though some, notably Piltdown Man, turned out to be hoaxes, some were confirmed as genuine. Although Darwin had openly spoken of "the descent of man" from earlier species, this point had tended not to sink in. While many churchgoers might have been content to believe that the horse evolved from the ancient proto-equus called eohippus, they were less than enthusiastic about evidence that Homo sapiens did not come about in a single divine act of creation. This put opposition to selection theory into play as an American public issue.

Another reason that teaching of evolution became a front-burner issue in the 1920s was that it was then that universal publicly funded high-school education was just becoming standard across the country; the question of just what the new high schools should teach was then very much on the minds of activists, newspaper editors, and politicians.
When public attention began to focus on the science versus religion aspect of Darwin's theory, some employed the opening for thoughtful debate, and others to promote an explicitly Christian agenda, instilling into the subject a danger that remains today, the use of what is ostensibly scientific arguments as a cover for promotion of a specific religion. (Read a chapter about the evolution debate in the 1920s from University of Georgia historian Edward Larson's Pulitzer Prize-winning book, "Summer for the Gods.")

But there was a public-spirited motive for the 1920s shift to fear of evolutionary thought. Many members of the clergy had grown terrified of the then-fashionable "Social Darwinism," which held that that "survival of the fittest" should be applied to human society. Social Darwinism maintained that the poor, the disabled, and the troubled--religion's historical first concern--should be weeded out for genetic reasons, and this idea was being openly praised by respectable figures. Darwin's cousin Francis Galton had published a book arguing for the selective breeding of human beings, dubbing his idea "eugenics." Norman Thomas, the most important American socialist of the early century, and himself a former minister, had announced that childbearing should be restricted among "inferior stock." And of course at the time in Germany, the incipient Nazi Party was beginning to speak of Social Darwinism as a philosophy of government.

Owing in no small part to religious fears of Social Darwinism, a move to ban the teaching of evolution began.