There is a missing link in human evolution about which few facts are known and surprisingly little has been written. It is not any one of the intermediate forms connecting modern man to his apelike ancestors. It is something much more challenging -- the early human mind. How did it come into existence? And why?

In this highly readable book, Charles J. Lumsden and Edward O. Wilson take us down the twisting corridors through which our species traveled in the two-million-year odyssey from Homo habilis to modern man. They ask why, out of the millions of species that have emerged and gone extinct, human beings alone took the last, abrupt journey to high intelligence and advanced culture. Lumsden and Wilson attribute the sudden emergence of the human mind to the activation of a mechanism both obedient to physical law and unique to man. This "Promethean fire" (an allusion to the original metaphor of the origin of mind) is geneculture coevolution, a mutually acting change in the genes and culture that carried man beyond the previous limits of biology -- yet restrains his nature on an elastic, unbreakable leash.

The authors' argument builds umpressively from across the entire range of biological and social sciences, but their presentation is essentially lyrical. They share with the reader their reconstructions -- both stunning line drawings and colorful vignettes -- of how the primitive mind may have functioned in exercising cultural choice with genetic bias. Step by step, they guide us through the diverse categories of evidence, including recent studies of incest avoidance, color vocabulary, infant gaze patterns, taste discriminations, and phobias, which led them toward the theory ofcultural transmission based on the importance of genetic filters in individual mental development.