About sixty million years ago, a small mammal rather like a weasel
or polecat clambered through the primeval forests. Its name was
Miacis and it was the ancestor of the group of animals we call canids:
the dog, jackal, wolf, and fox family.
Unlike Modern dogs that walk on their toes, Miacis was flat footed.
It had a carnivore’s teeth and a smallish brain, but was more intelligent
than its contemporaries, the creodonts, another group of primitive
meat-eaters. The creodonts were much more common than Miacis, but
gradually became extinct, the last one dying about twenty million
By around thirty-five million years ago, Miacis had given rise
to a variety of early canids. We know over forty types, some like
bears, some like hyenas, and some like cats. Some, however, were
like dogs: Cynodictis, for example, resembled a primitive Cardigan
Welsh Corgi. These dog-like canids were the only ones to survive
the evolutionary process, and some of them provided the basis for
the domestic dog.
Dogs as we know them first came on the scene in Eurasia between
12,000 and 14,000 years ago. From what kind of animal did they directly
spring? It was originally thought that their ancestor was a form
of jackal or jackal/wolf cross. Scientists now believe, however,
that it was the smaller southern strain of the gray wolf (Canis
lupus pallipes) still to be found in India. During the period in
question, the gray wolf (dispite its name, an animal with a wide
variety of coat colors) was distributed throughout Europe, Asia
and North America.
Other possible dog ancestors include the woolly wolf of northern
India and Tibet and the desert wolf of the Middle East. It is, however,
certain that all domestic dogs sprang from one of thse sources (or
possibly more than one in parallel development), and that they are
not genetically connected with any other species.
Because of their intelligence, versatility, and use of social co-operation
within the pack, wild dogs spread quickly all over the world. The
Dingo, however, which many believe was the basic type of Canis from
which the modern dog evolved, was already domesticated when it was
introduced to Australia thousands of years ago by the first immigrants.
Wild dogs were probably domesticated in different ways in different
parts of the world; some while scavenging for around human settlements,
others when early man hunted dogs for food and took litters of puppies
back to the homestead for fattening up.
From bones and fossils found around the world and dated back to
about 6500 years ago, we can say that at that period there were
five different types of dogs: mastiffs, wolf-like dogs, Greyhounds,
Pointer-type dogs, and sheepdogs. Since then, thousands of breeds
have been developed by both artificial and natural selection. But
over the centuries many have been lost, and only about 400 remain
When the Europeans first arrived in North and South America in
the fifteenth and sixteenth centuries, for example, they found at
least twenty distinct dog breeds: now the Mexican Hairless, Eskimo
Dog, and Peruvian and Chilean Wild Dogs are among the few surviving
natives. Other ancient breeds include the Basenji, native to Africa,
and, from the Middle East, the equally venerable Saluki and Afgan.