Domestic Dog

Canis lupus familiaris

The above two pictures were taken in Bloomington, Indiana, some time during the Spring of 1999. The dog’s name was Rickie Rehling.

The domestic dog is a subspecies of the wolf (Canis lupus). There is archaeological and genetic evidence that the first dogs were domesticated about 15,000 years ago. This would make dogs the first species to be domesticated by humans. There are estimated to be 400 million dogs in the world.

The dog has developed into hundreds of breeds with height ranging from a few inches in the Chihuahua to a few feet in the Irish Wolfhound, and large variations in color, hair texture, etc. Most of these breeds are recent, developed by humans by a process of artificial selection. Despite the huge differences between breeds, dogs are able to distinguish dogs from other kinds of animal.

Dogs generally retain some important features of their ancestors, such as powerful muscles, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing.

Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans. On the other hand, some breeds have a field of vision up to 270 (compared to 180 for humans). Dogs have also an excellent sense of smell.

Dogs are valued for their intelligence, which is expressed differently with different breeds and individuals. Dogs are employed in various roles across the globe, helping in areas such as search-and-rescue, law enforcement, herding, guiding the blind and acting as a pair of ears for the deaf, assisting with hunting, etc.

The loyalty and devotion that dogs demonstrate as part of their natural instincts as pack animals closely mimics the human idea of love and friendship, leading many dog owners to view their pets as full-fledged family members. Conversely, dogs seem to view their human companions as members of their pack, and make few, if any, distinctions between their owners and fellow dogs.

The following is a picture of Cleo, the dog of the honorary directors of the Foundalis Zoo, while she was a puppy. Cleo’s breed is “Jack Russel Terrier”.

Genus Canis
Family Canidae
Superfamily Canoidea
Order Carnivora
Subclass Eutheria
Class Mammalia
Subphylum Vertebrata
Phylum Chordata
Kingdom Animalia
Life on Earth
Index