Prehistoric Roots

Members of the genus Canis appeared about a million years ago, first in Asia or Eurasia, later migrating back and forth between these continents and the Americas, mainly within the Northern Hemisphere.

 At that time, the Eurasian continent and the Americas were not yet separated. As no fossils of dogs have yet been discovered in Australia, it is presently believed that dogs evolved well after this continent separated from the others.

Because the oldest fossil of a dog is reputed to be from the Mesolithic, discovered in Yorkshire, England, with the remains of a civilization, it is currently believed that some 500,000 years ago, during the Paleolithic had not yet developed a bond with dogs.

 Many early dog breeds evolved into their present form by adjusting to their habitat.  Breeds with ancient bloodlines, which often resemble wolves to appearance and jackals in habit, are said to be less aggressive than wolves as they were often scavengers, surviving mainly on the remains of other carnivores and animals.