Dog breeds have been bred by man for different works

The earliest of these Proto-Dogsor Wolf-Dogs,seem to have appeared around 33,000 years ago,and would not have looked all that different from their wild cousins.They were primarily distinguished by their smaller size and a shorter snout full of comparatively smaller teeth.But as human cultures and occupations became more diverse and specialized,so did our friends.Short stocky dogs to herd livestock by nipping their heels;elongated dogs to flush badgers and foxes out of burrows;thin and sleek dogs for racing;and large, muscular dogs for guard duty.With the emergence of kennel clubs and dog shows during England’s Victorian era,these dog types were standardized into breeds,with many new ones bred purely for appearance.Sadly, while all dog breeds are the product of artificial selection,some are healthier than others.