Domestic Dog

The domestic dog (Canis lupus familiaris) is the first animal domesticated by people, descended from gray wolves more than 15,000 years ago. Hundreds of breeds range from tiny lapdogs to giant mastiffs, and the dog is a model for genetics and for the co-evolution of humans and animals.

🧬 Field Guide Specimen: Open Domestic Dog in the CRV Science Field Guide to log the specimen, see its place among the Mammals lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.

Dogs share a common ancestor with a now-extinct population of wolves. Compared with wolves, many dogs carry extra copies of the amylase gene that digests starch, an adaptation to a human diet. Dogs also evolved the ability to read human gestures and gaze, and oxytocin appears to reinforce bonding between owners and dogs.

Canine transmissible venereal tumor is a cancer that spreads between dogs during mating. Its cells descend from a single animal that lived thousands of years ago, making it the oldest known continuously living cancer lineage. See Cancer.

Selective breeding concentrated desirable traits but also disease-causing variants. Because purebred dogs share the environments of their owners and have well-documented pedigrees, they are valuable models for human genetic disorders.

• Gray Wolf — the wild ancestor
• Red Fox — the Siberian domestication experiment
• Cancer — a contagious canine cancer