Within the world of popular science the subject of human evolution never goes out of fashion. While formerly one could complain that the number of new books on this topic bore little relation to the volume of new discoveries—a stray skull unearthed in Tanzania might unleash four books—this is no longer true. The growing literature on human origins reflects a real and substantial increase in our understanding of the biological history of human beings. Much of this improved understanding derives from new genetic data that allow us to date important evolutionary events and, in some cases, to trace the actual geographic routes traveled by early peoples over the earth.
The latest book to summarize the state of our understanding of human evolution comes from the science journalist Nicholas Wade, a reporter for The New York Times who covers biological and medical developments. Wade has also worked for the prestigious journals Nature and Science and has written a number of previous books, including The Nobel Duel (1981), about the competition over the 1978 prize for work on brain hormones, and Betrayers of the Truth: Fraud and Deceit in the Halls of Science (with William Broad, 1982). Wade’s latest work, Before the Dawn, is a broad survey of human evolution for lay readers which considers the emergence of man in his entirety: physical, psychological, and social. Unlike most popular treatments of human biology, Wade’s book concentrates on the recent evolutionary past: our last 50,000 years. Also unlike many popular treatments, Before the Dawn emphasizes genetic over paleontological evidence. In Wade’s story, it’s the genes, not the bones, that do most of the talking.
Before the Dawn suffers from some of the problems that mar many popular books on biology—misplaced cheerleading for big science (Wade credits the human genome project with findings that had nothing to do with that endeavor), lapses into breathless prose (“Some mysteries lie beyond the power even of DNA to resolve”), and unnecessary extended quotations from Charles Darwin (it helps if one’s views appear endorsed by the Master). But the book is, on the whole, a fascinating account of recent scientific findings. Wade is an especially skillful narrator and his recounting of the twists and turns of early human history is superb. He sketches the many physical and social changes that occurred as an African ape morphed into Homo sapiens, describes our species’s departure from Africa, and chronicles our subsequent migrations to different parts of the planet.
Before the Dawn is by design, though, more than a narrative. It is a book with a purpose, and a book that goes out of its way to court controversy. Wade is certain that natural selection shaped many aspects of human nature and that some of the genetic changes underlying the psychological adaptations he describes occurred surprisingly recently. Wade is plainspoken and he has a number of provocative things to say about the genetic basis of both human nature and race. Indeed …