In the rock formation a man sought to consolidate in several generations of well defined conformation-constitutional and behavioral characteristics. Selection for desired properties is inevitably accompanied by the loss of some inherent form Canis familiaris, properties in general. That is why no training will not make greyhound to sit at a roadblock and guard the warehouse, and St. Bernard – to catch a hare. 2. Social factors – these and a variety of events and turns of history and social order: practical and spiritual needs of man. The phenomenon of rock no analogues in the wild, since the breed – is sufficient for the largest group of animals that have a common origin, with specific exterior-constitutional and socio-economically beneficial properties, which staunchly inherited Because of this, in most classifications of dog breeds are as biological principles (Origin, kinship, ie, the genetic link), and the principle of polzovatelnyh properties. However, consistently sustain both of these principles in the classification of dog breeds, so that there were no contradictions, it is hardly possible.

In particular, common in the present classification of dog breeds developed by the International Canine Federation (FCI), is not free of such contradictions. Excellent example demonstrating the difficulty to clarify the common origin and construction of rock, leads AD Poyarkov. Thus, the Airedale is derived from the cross otterhaunda, Bull Terrier, other terriers. In addition, there may well be a setter, collie. That is, the Airedale is a mastiff similar blood, hounds, pointers, and possibly sheep dogs, but according to the classification refers to the FCI Airedale terrier group.