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Dogs: from 12,000 years ago

The earliest known evidence of a domesticated dog is a jawbone found in a cave in Iraq and dated to about 12,000 years ago. It differs from a wolf in that it has been bred to have a smaller jaw and teeth. Selective breeding affects a species quite rapidly, and is a natural process for man to initiate - probably at first by accident rather than intention. A particular puppy in a litter is favoured because it has an attractive coat, barks well, is unusually friendly or obedient, noticeably large or small.

This is the dog which is kept and in its turn has puppies. Its desirable characteristics become perpetuated.

Images in Egyptian paintings, Assyrian sculptures and Roman mosaics reveal that by the time of these civilizations there are many different shapes and sizes of dog. To use the word 'breed' may be anachronistic, though there is evidence that a dog very like the present-day Pekingese (almost as far as one can get from a wolf) exists in China by the 1st century AD.

By that time Roman ladies also have lap dogs; their warmth is believed to be a cure for stomach ache. A Roman writer of the period gives similarly practical reasons for selecting the colour of a dog: shepherds' dogs should be white (to distinguish them from wolves in the dark) but a farmyard dog should have a black coat (to frighten thieves).