The grey wolf (Canis lupus), commonly known as wolf, is known to share genetic similarities with the domestic dog (Canis lupus familiaris). While they both share some similar characteristics and genetic material, their physical appearance and behavioral attitudes differ largely.
“Dr. Temple Grandin, animal behavioral geneticist at Colorado State University, claims that domestication is best defined as “a process by which a population of animals becomes adapted to man and the captive environment by some combination of genetic changes occurring over generations” (Grandin & Deesing, 1998) (Miles)
The main reason for the physical and behavioural differences between dogs and wolves would be domestication.
As a dog undergoes domestication when it is young, it stays in the same behavioural state as that of a wolf pup. They are the striking example of the retention of juvenile attributes in grown up dogs. This is known as neoteny. Examples of similar behaviour would be obedience and submissiveness. Not only are their behavioural attitudes similar to wolf pups, their physical outlook also bears more resemblance to the wolf pups than to the grown up wolves.
Domestication also affects different behaviours such as a dog barking and a wolf howling. Barking is commonly seen to be developed through domestication as a warning system to humans. (Miles)
References:
Coppinger R, Feinstein M: ‘Hark! Hark! The dogs do bark…’ and bark and hark. Smithsonian 21:119-128, 1991
Richard Murray and Helen Penridge. Dogs and Cats in the Urban Environment: A Handbook of Municipal Pet Management. Second edition, 2001, ch. 11
Differences Between Wolves and Domestic Dogs. (n.d.). Retrieved March 2010, from In the Company of Wolves: http://www.wolfdog.ws/html/differences.html
Miles, K. (n.d.). Of Wolves & Dogs: Dispelling the Myths. Retrieved March 2010, from Florida Lupine Association, Inc.: http://www.floridalupine.org/publications/PDF/Of_Wolves_and_Dogs–Dispelling_the_Myths.pdf
“Snow Wolf” by Tambako the Jaguar on Flickr, April 2010. URL: http://www.flickr.com/photos/tambako/3315654039/
“Wolf Mix” by Rennett Stowe on Flickr, April 2010. URL: http://www.flickr.com/photos/tomsaint/3117105850/