Facts on Domesticated Dogs

With more than 75 million dogs living in homes in the U.S. alone, it's time to learn some basic facts about man's best friend. Dogs have been domesticated for more than 10,000 years. The oldest documented remains of a dog date back 11,000 to 12,000 years ago. During this time, humans have bred more than 400 breeds of domesticated dogs.

  1. Ancestry

    • All dogs, whether they're chihuahuas or malamutes, share a common ancestor. In a study published in 1997 in Science magazine, researchers studied the mitochondrial DNA of wolves and domestic dogs. The results of their analysis supports the theory that the wolf is the ancestor of the domesticated dog. The specific wolf is the small South Asian wolf.

    Similarities to Ancestors

    • Most domesticated dogs look very different today than their ancestors, but they do continue to share some behaviors with their wolf, fox, and jackal relatives. Both mark and defend their territories and also bury prized possessions. Domesticated dogs often bury their bones or toys in the same way their wild relatives bury their food. These relatives also share communication skills. Each uses scent and physical appearance to communicate with other animals and humans.

    Breeds

    • Dogs have been bred for many different purposes. The American Kennel Club categorizes dog breeds by the purpose for which the dog was bred. These purposes include companionship, hunting, guarding and herding. Different breeds range from six to 33 inches in height at the shoulder and weigh anywhere from three to 175 pounds. The breeds of domesticated dogs do share some common characteristics. They reach sexual maturity between 10 and 12 months and have an average of a 63-day gestation period. Domesticated dogs have a life span of 12 years or more, although smaller breeds tend to live longer than larger breeds.

    Impact of Breeding and Domestication

    • Many dog breeds could never survive in the wild today because of their very breeding. Dogs bred for the appearance of a pushed-in muzzle, for example, would have a difficult time hunting for food. Further, dogs rely on humans so much today that they have low problem-solving skills. Dingoes will outperform dogs on any non-social problem-solving tasks, scientists concluded in a study reported on by Discovery News in 2010.