Dogs in Service to Humans
Fossil evidence suggests that canids in the form of wolves evolved at least 3 million years ago and were present during the Pleistocene ice age (Ensminger, 1977). Wolves were the first ani mals domesticated by humans. This process probably began 50,000 years ago when packs of wolves followed bands of humans to feed on the remains of their hunts (Wilcox Sc Walkowicz, 1993). We can only speculate about how the wolf (Canis lupus) became the dog (Canis familiaris), but it is plausible that wolf pups were found and tamed by humans (Scott, 1968). Perhaps adult wolves who regularly fol lowed a human group were eventually baited in by food and attached themselves to the human pack (Wilson, 1975). Over the course of many centuries humans probably selected canines who were neotenous, that is, retained some puppy appearance and behavior. The first dogs emerged from this selection process with a dif ferent tail carriage and skull and jaw conforma tions, but the same dentition. The dog and the wolf retained the same fundamental genetic structure and can readily interbreed.