The intertwined journey of human and dog has spurred the interest of anthropologists, biologists, historians, sociologists, and behavioral scientists. After all, the dog is "man's best friend," so it is natural that people have wondered about how, why, from where, and when dogs came to be.

"From where?" seems simple enough to answer--one needs only to look at the dog's wild brother and, with Darwin's blessing, conclude that the dog's origin is the wolf. The rest of the questions are more difficult to answer, because the original assumption has led people astray. Nonetheless, the...