CHILDREN OF PROMETHEUS: The Accelerating Pace of Human Evolution. By Christopher Wills. Perseus Books. 288 pp. $25

With the recurrent political and religious assaults on "Darwinism," it remains worth arguing that humankind has evolved and is still evolving. Children of Prometheus advances the argument more effectively than most books, whether scholarly or popular. Wills, a professor of biology at the University of California, San Diego, makes a broad selection of recent findings genuinely accessible to general readers, including students. Technical parts of the argument—such as the presentation of balanced genetic polymorphism and the forces of natural selection sustaining it—read smoothly, betraying none of the labor that must have gone into the writing.

Moreover, Wills goes a crucial step further. He emphasizes and supports the claim that human evolution—real biological evolution, not just cultural change—is accelerating. Our species has been evolving quickly by ordinary standards (for example, those for other primates) and the pace is speeding up. Although only small differences in overall DNA composition separate us from our nearest relatives, the chimpanzees, those gene differences have produced huge structural and other phenotypic changes, enabling humans to outdistance the chimps since the two lineages separated. Much of the book is devoted to explaining the reasons and mechanisms for the acceleration.

Wills argues that the distinction between human biological and cultural evolution is a false one. The two are locked in a positivefeedback loop, whereby evolution of cognitive capacity (which at first had to be genetic) results in a greater ability to alter the environment. Those alterations produce powerful selective forces in favor of enlarged and novel cognitive capacities for coping with environmental stress. The enlarged capacities lead to further (sometimes destructive) changes in the environment. And so on. Meanwhile, migrations enlarge the gene pool of merged human (or hominid) populations. Thus, the supply of genetic variation—the raw material of evolution— increases as cultural change fuels environmental change. A strength of the book is its exposition of this feedback loop.

Other elements are not so solidly established. The author makes a politically correct attempt to dismiss Bell Curve-style hereditarianism—which, given that Wills’s whole argument rests on the biological bases of cognitive ability, seems rather unconvincing. Elsewhere, Wills gives the still-emerging story of Neanderthals the same billing, and its conjectures (which is what they are) the same weight, as much more secure findings. He waxes lyrical about the recent discovery, in a cave that was probably inhabited by Neanderthals, of a 50,000-year-old fragment of hollowed-out bone in which symmetrical holes appear to have been punched. Like others, he speculates that this object was a flute, hence that the Neanderthals had music, a conclusion that would significantly alter our view of their capacities and history. But of course the object might well not have been a flute. The extended chain of guesses that follows, interesting and even plausible as it is, ought to be more clearly identified as such.

Still, this is an authoritative antidote to the witless but trendy calumny that evolution, specifically "Darwinism," is just a tired 19th-century idea, ripe for overthrowing.

—Paul R. Gross