How Domestic Animals Become Distinct Breeds

Within the canine family, there is a separate division for true dogs (Canis), which includes wolves, coyotes, jackals and wild dogs, and another for true foxes (Vulpes). Despite both being canines, true dogs and true foxes cannot successfully interbreed with each other. There are no fox/dog hybrids, even though foxes and dogs have been seen to mate with each other, but foxes can breed successfully with other foxes, regardless of type, just as wolves and coyotes can interbreed.

Among the 40-odd subspecies of the grey wolf are the Mexican wolf, Ethiopian wolf, Arctic wolf and, surprisingly enough, the domestic dog. Yes, domestic dogs are a type of wolf.

The next division applies only to domestic animals. This is the separation into breeds based on similarities of size, behaviour, coat type, colour and so on. Whether you are talking about dogs or cattle or any other domesticated animal, there are certain characteristics and requirements that define a breed. In order to be classed as a pure breed, they must always produce offspring that look and act like other members of that breed when bred to each other. That is known as breeding true to type. Breed registries keep track of individual animals and record the offspring when two registered animals of the same breed are bred to each other. This database helps keep a breed pure and ensures that the offspring won't look like something else. If someone is breeding Clydesdale horses, the owner wants each foal to look like a Clydesdale, not like a pony or a racehorse.

A pedigree simply lists ancestry. It's a family tree. Even a mutt has a pedigree, if you know the names of its parents, grandparents and so on. But to be a purebred, every animal in the pedigree must be purebred and also of the same breed.

This is how all ancient breeds came into being. Selection for specific traits over many generations and sometimes hundreds of years resulted in types that looked and behaved in a similar fashion. There are many other pure breeds of animals whose origins rest in the distant past, including Arabian horses, Brahmin cattle, Cotswold sheep and angora goats.

In the case of ancient dog breeds registered and shown today, occasionally pure stock with ancestry not recorded in the existing database may be added from its country or area of origin to broaden the breeding base and correct genetic illnesses that may have come with the early registered animals. If such new animals are added, a strict record is kept to ensure that their offspring and descendants continue to meet the breed requirements.

This was done in the 1980s with the Basenji, an ancient hunting breed from Africa. Bringing in new dogs directly from African villages to cross with registered Basenjis in the United States strengthened the breed's overall health without changing type.

Sometimes breeds evolve from other breeds. With the advent of dog shows and competitions in the nineteenth century, individuals or groups of people with an interest in a similar kind of dog began making an effort to breed type to type with more specific requirements than previously. This created many breeds which shared certain characteristics but differed in others, even when they performed the same kind of task.

Breed standards were created for the various types within each category. For example, hunting spaniels in Great Britain originally were bred amongst each other, but after they were split into two types — Springers (larger flushing spaniels) and Cockers (small flushing spaniels) — crossbreeding stopped. Then these were further divided, so that today we have several breeds of hunting spaniels originating in Great Britain, including the English and Welsh Springer Spaniel and the Field, Cocker, Sussex and Clumber Spaniels, none of which are crossbred with each other. Cockers were later split once more by type into American and English Cockers.

This method also has been used to recreate or rescue breeds that are on the brink of extinction, as occurred with both the Irish Wolfhound and several European dog breeds decimated by two world wars. Breeders began with an existing standard, then tried to produce animals that matched it in order to restore the breed.

When there are no purebred animals left, breeders will use any crossbred animals that contain some of the desired bloodline of the lost breed. These can be bred to each other, then the offspring that appear most like the breed being rescued will be used for breeding, until several generations later the type has been recreated. This is called backbreeding.

If the number of animals available is very small, sometimes a cross to a similar breed is needed to bring back characteristics that needed strengthening. In the case of the Irish Wolfhound, crosses with Scottish Deerhounds were used to help the breed recover.

Backbreeding can even be done to some degree with wild animals. The Tarpan, a wild horse from Europe, has been duplicated to the point that today's Tarpan closely resembles the now-extinct original Tarpan, at least in physical appearance. It was recreated using domestic horses that contained some Tarpan blood. Attempts are underway to try and recreate the Quagga, an extinct variety of zebra, by breeding together zebras that most closely resemble the Quagga. The use of DNA analysis and possibly the future use of cloning from museum specimens could prove to be excellent tools in this type of backbreeding.

A third way to create a breed, or to define an existing breed more clearly, is by developing a breed standard based on one desirable animal. Breeders might get together and vote of the best representative of the breed and use that dog as a blueprint for the breed standard, minus any faults he might have and including any variations permitted in size, colour, coat type, etc.. In the case of a new breed based on a single dog, that first dog would be considered the model for the breed.

The Kromfohrlander, a small companion dog breed created in Germany in the 1940s, was based on one dog of unknown background and its offspring. Today, it is a recognized breed in Europe. Another example of such a breed is the Alaskan Klee Kai, which also was developed around one dog.

In horses, a single stallion of exceptional merit called Figure, owned by a schoolteacher named Justin Morgan, became the basis for a new breed. After his death, Figure became known by his owner's name, and an entire breed called the Morgan Horse was created based on him and his offspring. The Cornish Rex is a breed of cat that began with a single kitten that was born with an unusual coat texture that it passed on to successive generations.