Dog breeds are defined as groups of closely related and visibly similar domestic dogs. All dog breeds are members of the subspecies Canis lupus familiaris and all have characteristic traits that are selected and maintained through breeding by humans. A given dog breed is bred from a known foundation stock.
The term dog breed also refers to those natural breeds (landraces) which developed naturally over time in response to particular environmental factors, which included their association with humans, but with little or no selective breeding by humans. Such undocumented breeds are identified by their appearance and, most often, by the type work they do. The ancient dog breeds represent some of the modern, and now documented, descendants of these natural breeds.
It surprises many that dog breeds are not actually scientifically defined biological classifications. They are, rather, groupings designated by clubs of hobbyists known as breed clubs. The naming of a dog breed is considered when by a sufficient number of individual animals exist to stably transfer the specific characteristics of the breed over generations to come. A single breed of dogs will have similar characteristics of appearance and behavior. This is primarily because all members of the same breed come from a select set of ancestors presenting those same characteristics.
Specific breeds of dog will reproduce true, producing their young with closely similar traits to the parents. Each individual dog can be identified as a member of its breed through proof of ancestry. Both genetic analysis and written records of ancestry may be used. Without the benefit of such proof, identification of a specific breed is rarely reliable. These records, known as stud books, are typically maintained by individuals, or clubs and other organizations.
It really is all about dog breeds!