The Domestic Dog


Different dogs. Courtesy of Ellegren, H. 2005

"Dogs are not our whole life, but they make our lives whole."  ~Roger Caras


Canis lupus familiaris, also known as the domestic dog, is one of the most popular pets. The word "dog" can be traced back to the Old English word docga, which means a "powerful breed of canine". Dogs have been called "Man's best friend" due to their lo compassion for their humans owners. Many owners see their dogs as more than just a pet, they see them has part of the family. The top five most popular dogs are Labrador Retrievers, Golden Retrievers,  Yorkshire Terriers, German Shepherds, and Beagles.


Dog mosaic showing hunting from the floor of a Roman villa. Courtesy of Mosesofmason

For years the domestic dog was classified as a distinct species, Canis familiaris. However, recent DNA analysis shows that dogs evolved from wolves, Canis lupus. This has led scientists to reclassify the domestic dog as Canis lupus familiaris, a subspecies of the wolf rather than a separate species. Scientists believe that 15,000 years ago the grey wolf was domesticated in central Asia. There is some DNA evidence and fossil records that show those wolves may have been domesticated as early as 150,000 years ago.



In this time dogs have developed into hundreds of breeds. They range in size from the very small Chihuahua that can weigh as little as 2 pounds, to the St. Bernard that can weigh as much as 200 pounds. There are also many different heights of dogs. The Short-legged Miniature Dachshund that stands 5-9 inches at the shoulder to the Irish Wolfhound which stands 28-35 inches at the shoulder. Throughout the years humans have influenced the domestic dog to include different types of ears, tails, coats, colors, temperament, and functions. No matter what the dog looks like, it can breed with any other dog and with their wild relative, the wolf.  


To learn more about the dog's classification, click here.

To learn more about other organisms, click here.