It seems dogs have always been “Man’s Best Friend.” The relationship goes back thousands of years to a time when wolves (Canis lupus) likely hung out at the fringes of human settlement hoping for scraps of food or to seek warmth from a fire. No one knows for sure when wolves and human beings officially began their mutually beneficial partnership, but some of the oldest known domesticated dogs in North America were found at the Koster Site in Greene County. The remains of four dogs were intentionally buried near human burials there about 8,500 years ago. Because their anatomy varies from wolves, it is clear these dogs were the product of generations of selection by their human counterparts. When living organisms change and evolve over time, we call that natural selection. When people select which plants or animals to breed, depending on which traits are desirable, it is called unnatural selection. By selecting various traits when breeding dogs, humans have created a wide variety of breeds to serve various purposes, including hunting, security, companionship, and more. All of them are known as Canis lupus familiaris. The American Kennel Club currently recognizes 190 breeds.
If anything, our relationship with dogs as companion animals has continued to grow. In the United States, more than one-third of all households have a dog. In all, there were more than 43 million dogs in the U.S. in 2012 according to the American Veterinary Medical Association.