Dog breeding has become a science. Once ferocious wild dogs and wolves have, over the centuries, been bred into domesticated, loveable pets that sit on your lap and sleep on your pillow. We have even bred dogs for specific purposes. The greyhound was bred for speed. The sheepdog was bred to herd sheep. The dachshund or badger dog was bred in Germany to fetch small animals from their burrows. Like the pit bull, bulldogs were originally bred to help butchers control livestock. The Yorkshire terrier was bred just to look cute (I think). We have taken wild animals and domesticated them to serve our own purposes.