"In the managed evolution of dogs, which has produced a remarkable range of working and hunting breeds, the writers perceive both environmental and genetic factors. Through these new perceptions regarding the mechanics and tenacity of inbred and enhanced behavioral traits, humans can better understand the primal biological motivations of their canine companions. Chock full of both scientific studies and personal experiences, this fast-paced, absorbing book deserves a wide audience."-- "Publishers Weekly (starred review)"