Preface

D ecember 20, 2005. Like many scientists on that day, I awoke feeling anxious. John Jones III, a federal judge in Harrisburg, Pennsylvania, was due to issue his ruling in the case of Kitzmiller et al. vs. Dover Area School District et al. It had been a watershed trial, and Jones’s judgment would decide how American schoolchildren would learn about evolution.

The educational and scientific crisis had begun modestly enough, when administrators of the Dover, Pennsylvania, school district met to discuss which biology textbooks to order for the local high school. Some religious members of the school board, unhappy with the current text’s adherence to Darwinian evolution, suggested alternative books that included the biblical theory of creationism. After heated wrangling, the board passed a resolution requiring biology teachers at Dover High to read the following statement to their ninth-grade classes:

The Pennsylvania Academic Standards require students to learn about Darwin’s Theory of Evolution and eventually to take a standardized test of which evolution is a part. Because Darwin’s Theory is a theory, it continues to be tested as new evidence is discovered. The Theory is not a fact. Gaps in the Theory exist for which there is no evidence…. Intelligent design is an explanation of the origin of life that differs from Darwin’s view. The reference book Of Pandas and People is available for students to see if they would like to explore this view in an effort to gain an understanding of what intelligent design actually involves. As is true with any theory, students are encouraged to keep an open mind.

This ignited an educational firestorm. Two of the nine school board members resigned, and all the biology teachers refused to read the statement to their classes, protesting that “intelligent design” was religion rather than science. Since offering religious instruction in public schools violates the United States Constitution, eleven outraged parents took the case to court.

The trial began on September 26, 2005, lasting six weeks. It was a colorful affair, justifiably billed as the “Scopes Trial of our century,” after the famous 1925 trial in which high school teacher John Scopes, from Dayton, Tennessee, was convicted for teaching that humans had evolved. The national press descended on the sleepy town of Dover, much as it had eighty years earlier on the sleepier town of Dayton. Even Charles Darwin’s great-great-grandson, Matthew Chapman, showed up, researching a book about the trial.

By all accounts it was a rout. The prosecution was canny and well prepared, the defense lackluster. The star scientist testifying for the defense admitted that his definition of “science” was so broad that it could include astrology. And in the end, Of Pandas and People was shown to be a put-up job, a creationist book in which the word “creation” had simply been replaced by the words “intelligent design.”

But the case was not open and shut. Judge Jones was a George W. Bush appointee, a devoted churchgoer, and a conservative Republican—not exactly pro-Darwinian credentials. Everyone held their breath and waited nervously.

Five days before Christmas, Judge Jones handed down his decision—in favor of evolution. He didn’t mince words, ruling that the school board’s policy was one of “breathtaking inanity,” that the defendants had lied when claiming they had no religious motivations, and, most important, that intelligent design was just recycled creationism:

It is our view that a reasonable, objective observer would, after reviewing both the voluminous record in this case, and our narrative, reach the inescapable conclusion that ID is an interesting theological argument, but that it is not science…. In summary, the [school board’s] disclaimer singles out the theory of evolution for special treatment, misrepresents its status in the scientific community, causes students to doubt its validity without scientific justification, presents students with a religious alternative masquerading as a scientific theory, directs them to consult a creationist text [Of Pandas and People] as though it were a science resource, and instructs students to forego scientific inquiry in the public school classroom and instead to seek out religious instruction elsewhere.

Jones also brushed aside the defense’s claim that the theory of evolution was fatally flawed:

To be sure, Darwin’s theory of evolution is imperfect. However, the fact that a scientific theory cannot yet render an explanation on every point should not be used as a pretext to thrust an untestable alternative hypothesis grounded in religion into the science classroom to misrepresent well-established scientific propositions.

But scientific truth is decided by scientists, not by judges. What Jones had done was simply prevent an established truth from being muddled by biased and dogmatic opponents. Nevertheless, his ruling was a splendid victory for American schoolchildren, for evolution, and, indeed, for science itself.

All the same, it wasn’t a time to gloat. This was certainly not the last battle we’d have to fight to keep evolution from being censored in the schools. During more than twenty-five years of teaching and defending evolutionary biology, I’ve learned that creationism is like the inflatable roly-poly clown I played with as a child: when you punch it, it briefly goes down, but then pops back up. And while the Dover trial is an American story, creationism isn’t a uniquely American problem. Creationists—who aren’t necessarily Christians—are establishing footholds in other parts of the world, especially the United Kingdom, Australia, and Turkey. The battle for evolution seems never-ending. And the battle is part of a wider war, a war between rationality and superstition. What is at stake is nothing less than science itself and all the benefits it offers to society.

The mantra of evolution’s opponents, whether in America or elsewhere, is always the same: “The theory of evolution is in crisis.” The implication is that there are some profound observations about nature that conflict with Darwinism. But evolution is far more than a “theory,” let alone a theory in crisis. Evolution is a fact. And far from casting doubt on Darwinism, the evidence gathered by scientists over the past century and a half supports it completely, showing that evolution happened, and that it happened largely as Darwin proposed, through the workings of natural selection.

This book lays out the main lines of evidence for evolution. For those who oppose Darwinism purely as a matter of faith, no amount of evidence will do—theirs is a belief not based on reason. But for the many who find themselves uncertain, or who accept evolution but are not sure how to argue their case, this volume gives a succinct summary of why modern science recognizes evolution as true. I offer it in the hope that people everywhere may share my wonder at the sheer explanatory power of Darwinian evolution, and may face its implications without fear.

Any book on evolutionary biology is necessarily a collaboration, for the field enfolds areas as diverse as paleontology, molecular biology, population genetics, and biogeography; no one person could ever master them all. I am grateful for the help and advice of many colleagues who have patiently instructed me and corrected my errors. These include Richard Abbott, Spencer Barrett, Andrew Berry, Deborah Charlesworth, Peter Crane, Mick Ellison, Rob Fleischer, Peter Grant, Matthew Harris, Jim Hopson, David Jablonski, Farish Jenkins, Emily Kay, Philip Kitcher, Rich Lenski, Mark Norell, Steve Pinker, Trevor Price, Donald Prothero, Steve Pruett-Jones, Bob Richards, Callum Ross, Doug Schemske, Paul Sereno, Neil Shubin, Janice Spofford, Douglas Theobald, Jason Weir, Steve Yanoviak, and Anne Yoder. I apologize to those whose names have been inadvertently omitted, and exculpate all but myself for any remaining errors. I am especially grateful to Matthew Cobb, Naomi Fein, Hopi Hoekstra, Latha Menon, and Brit Smith, who read and critiqued the entire manuscript. The book would have been substantially poorer without the hard work and artistic acumen of the illustrator, Kalliopi Monoyios. Finally, I am grateful to my agent, John Brockman, who agreed that people needed to hear the evidence for evolution, and to my editor at Viking Penguin, Wendy Wolf, for her help and support.