Coppinger and Feinstein examine dogs in this work with the unerring gaze of science as a biological species rather than as a cuddly pet. They summarize decades of research and field experiments in an easily understandable manner to explain the evolutionary foundations underlying our dogs' behavior. They investigate questions such as how the physical body (including genes and brain) influences behavior in various external forms, how this has developed over time, why dogs play or bark, how they feed, the state of their cognitive abilities, and the significance of the early relationship between mother dog and puppies. A foundational work for anyone who wants to better understand dog behavior.