Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The origin of the domestic dog (Canis lupus familiaris) began with the domestication of the gray wolf (Canis lupus) several tens of thousands of years ago. Domesticated dogs provided early humans with a guard animal, a source of food, fur, and a beast of burden. The process continues to this day, as the intentional cross-breeding of dogs continues, to create the so called "designer dogs".