Review: Why Evolution is True
Work under Review
In recent years, the battles over creationism, "intelligent design", and evolution have produced a glut of new books on the topic. Most of the books focus on the purely biological side of evolution; a few (including mine) focus on the fossil evidence. Jerry Coyne's new book, Why Evolution is True, does a beautiful job of covering nearly all the bases in a succinct but enjoyable and gently persuasive fashion.
In the first chapter, Coyne discusses the basic conceptual framework of evolution, and clarifies the common misconceptions about how the science works, and the creationist misuse of the word "theory". The second chapter is a brief but compelling overview of the fossil evidence of evolution, drawing from the most familiar recent examples (Tiktaalik and the origin of tetrapods, the origin of birds from dinosaurs, and the origin of whales) as well as some that are more obscure. Even though Coyne is a neontologist, he does a good job of showing the difficulties that paleontologists endure while finding fossils, the strengths and limitations of the fossil record, and how important the fossil evidence has become for establishing the actual course of evolution. Given the limited, outdated, and inaccurate coverage of the fossil record in most college-level evolutionary biology textbooks, it is a pleasure to see paleontology given a seat at the "high table" of evolutionary biology, even before any of the neontological evidence has been mentioned. I have some small quibbles about outdated taxonomy and Coyne's insistence on gradualism (which most paleontologists would dispute), but overall this is one of the best summaries of the fossil evidence for evolution that I've ever seen by a non-paleontologist.
The third chapter outlines the "mute witnesses" of evolution in the form of vestigial organs and suboptimal or bad design — the best possible antidote to the foolishness of the "intelligent design" argument. More than anything else, pointing to these strange examples of useless or poorly designed features is a powerful argument for evolution, and quickly disarms those who might be seduced by the phony "design argument". Coyne covers most of the classics and many lesser-known examples, from whale hips and legs, human tails, and many other features of the human body that are poorly designed, to "dead genes" and other junk in our DNA. Most impressive of all is the bizarre course of the left recurrent laryngeal nerve, which takes an unnecessarily long course down from the throat to the aorta and back again, since it was once attached to a gill arch in the developing embryo. In the fourth chapter, Coyne reviews all the overwhelming evidence from biogeography, from islands and their peculiar biotas to the odd patterns left over from the breakup of Pangaea.
Chapters 5, 6, and 7 cover the classic neontological arguments from genetics, speciation theory, and the evidence that modern biologists have been documenting for the past century. This is the strength of the book, since Coyne's specialty is in these areas, and here his familiarity with the field truly shows. Among these topics is a provocative discussion of "how sex drives evolution", updating the classic sexual selection arguments that Darwin first presented, which were amplified when genetics discovered how important sexual recombination was to genetic variability and speciation.
The penultimate chapter deals with the issue most driving the creationist movement: human evolution. Many creationists would probably ignore evolution (along with the rest of biology) completely were it not for the claim that humans are related to the rest of the animal kingdom, and evolved from non-human ancestors. Coyne presents a brief but clear summary of all the evidence from human anatomy, paleontology, and genetics that make our connection to the animal kingdom (and especially the great apes) indisputable.
In his final chapter, "Evolution Redux," Coyne muses on some of the major implications of evolution, from the philosophical reasons why a scientist can say "evolution is true," to the new field of evolutionary psychology, to the implications of evolution for our worldview. He never spends much time engaging the creationists directly or debunking most of their arguments, but instead gently convinces the reader by clearly and simply describing and explaining the overwhelming evidence that evolution occurred — much as Darwin did 150 years ago. In this way, Coyne's book is a wonderfully balanced approach that is gently persuasive without being combative, and works well for anyone who is sitting on the fence about the fact of evolution. Of course, creationists will hate a book like this (judging from the Amazon.com reviews, many have already tried to trash it), but it should convince anyone with doubts about the issue, or whose mind is not already clouded by religious dogma.
Donald R Prothero
Department of Geology
Los Angeles CA 90041
Donald R Prothero is Professor of Geology at Occidental College, and Lecturer in Geobiology at the California Institute of Technology. He is the author of twenty-four books, including Evolution: What the Fossils Say and Why it Matters (New York: Columbia University Press, 2007).