Spencer Wells traces human evolution back to our very first ancestor in The Journey of Man. Along the way, he sums up the explosive effect of new techniques in genetics on the field of evolutionary biology and all available evidence from the fossil record. Wells's seemingly sexist title is purposeful: he argues that the Y chromosome gives us a unique opportunity to follow our migratory heritage back to a sort of Adam, just as earlier work in mitochondrial DNA allowed the identification of Eve, mother of all Homo sapiens. While his descriptions of the advances made by such luminary scientists as Richard Lewontin and Luigi Luca Cavalli-Sforza can be dry, Wells comes through with sparkling metaphors when it counts, as when he compares genetic drift to a bouillabaisse recipe handed down through a village's generations. Though finding our primal male is an exciting prospect, the real revolution Wells describes is racial. Or rather, nonracial, as he reiterates the scientific truth that our notions of what makes us different from each other are purely cultural, not based in biology. The case for an "out of Africa" scenario of human migration is solid in this book, though Wells makes it clear when he is hypothesizing anything controversial. Readers interested in a fairly technical, but not overwhelming, summary of the remarkable conclusions of 21st-century human evolutionary biology will find The Journey of Man a perfect primer. --Therese Littleton