Teaching Evolution Has a Bright Future in the U.S.

Teaching Evolution Has a Bright Future in the U.S.

By Glenn Branch edited by Daniel Vergano

One hundred years ago a young teacher, John T. Scopes, went on trial in Dayton, Tenn., for violating a recently enacted state law that forbade the state’s educators “to teach any theory that denies the story of the Divine Creation of man as taught in the Bible, and to teach instead that man has descended from a lower order of animals.” Ever since religiously motivated attempts to undermine the teaching of evolution in the U.S.’s public schools have not only continued but also adapted in response to legal setbacks.

Today, however, there are encouraging trends that suggest that the arc of history is bending toward teaching evolution.

Famously, Scopes was convicted, and although the conviction was overturned on appeal, the Butler Act, under which he was prosecuted, remained on the books—and was joined by similar laws enacted in Arkansas and Mississippi later in the 1920s. It was not until 1967 that the Tennessee legislature repealed the Butler Act, partly in reaction to the negative publicity surrounding the Scopes trial provoked by the Hollywood blockbuster Inherit the Wind. In the following year the Arkansas law was struck down as unconstitutional by the Supreme Court in its decision in Epperson v. Arkansas, and its Mississippi counterpart was similarly ruled to be unconstitutional by the state’s highest court in 1970.

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A second wave of attacks on evolution education ensued. Their strategy was not to ban the teaching of evolution but to “balance” it by requiring the teaching of such purportedly scientifically credible—but clearly religiously motivated—alternatives to evolution as biblical creationism, creation science and intelligent design. These attacks were unsuccessful, thanks to a series of decisions in the federal courts. The most recent came in Kitzmiller v. Dover, the 2005 case in which a Pennsylvania school district’s policy of requiring teachers to recommend intelligent design to their students as a scientifically credible alternative to evolution was found unconstitutional.

Anticipating the Kitzmiller decision, a third wave of attacks emerged early in the 21st century. The new strategy was not to ban or to balance the teaching of evolution but to blunt it by requiring, or more commonly permitting, teachers to misrepresent evolution as scientifically controversial. A handful of states—Mississippi, Louisiana and Tennessee—presently have such laws on the books. It is difficult to challenge these laws as unconstitutional in the abstract without a teacher who actually claims their protection to proselytize against evolution to their students. But it is also unclear whether any teachers have taken the opportunity to miseducate their students about evolution.

What is clear, however, is that the teaching of evolution in American public schools is improving. Comparing nationally representative surveys of public high school biology teachers conducted in 2007 against 2019 reveals that more is being taught about evolution in general—and substantially more is being taught about human evolution, which, as the wording of the Butler Act suggests, is especially contentious. And while in 2007 a bare majority of these teachers reported that they emphasized the scientific credibility of evolution while not emphasizing creationism as a scientifically credible alternative, in 2019 it was a commanding majority, 67 percent, who did so.

What accounts for such a striking improvement in the emphasis on evolution in the high school biology classroom? The cause is partly the improved treatment of evolution in state science standards, which specify what knowledge and know-how students are expected to acquire in the course of their K–12 science education. The majority of state science standards are now based on a National Research Council framework that recognizes as a core principle of the life sciences “that all organisms are related by evolution and that evolutionary processes have led to the tremendous diversity of the biosphere.” So there are incentives to ensure that science educators are equipped and encouraged to teach accordingly.

There is still plenty of room for improvement: even in the 2019 survey, 17.6 percent of high school biology teachers—more than one in six—reported emphasizing, wrongly, that creationism is a scientifically credible alternative to evolution. Many of those teachers were creationists themselves: 10.5 percent of respondents indicated that they personally agreed that “God created human beings pretty much in their present form at one time within the last 10,000 years or so.” The remainder presented creationism as scientifically credible presumably as a result of inadequate preparation or community pressure, whether implicit or explicit.

And there is still reason for concern about attempts to undermine the teaching of evolution in the public schools. As recently as 2024, the West Virginia legislature considered a bill that, as introduced, would have allowed public school teachers to present “intelligent design as a theory of how the universe and/or humanity came to exist.” Fortunately, the reference to intelligent design was removed before the bill passed. Even so, such concerns are newly urgent in light of the Supreme Court’s recent abandonment of the legal tests for whether a government action is constitutional that enabled the successful litigation against the second wave of attacks on evolution education.

Nevertheless, despite the occasional outbreak of explicit attacks and a background level of implicit hostility across the country, creationist attacks on evolution education are on the wane. Acceptance of evolution became a majority position among the American public more than a decade ago, according to multiple independent polls, and there are signs of a shift even among religious communities that have been traditionally hostile to evolution. In short, a century after Scopes’s eight-day trial ended, there’s now reason to hope that someday every student in the U.S.’s public schools will be in a position to appreciate that nothing in biology makes sense except in the light of evolution.

Disclosure: The author of this article is deputy director of the National Center for Science Education, which was on the plaintiff’s legal team in the Kitzmiller v. Dover case in 2005 and conducted the 2019 survey of science teachers with Eric Plutzer of Pennsylvania State University.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.