There are four main types of dogs today, and these include the Old English Sheepdog, the Sporting Greyhound, the Terrier, and the Toy and Miniature Poodle. The domestic dog is probably the most common aquatic carnivore and is by far the most populous land carnivore. The wolf and the extinct grey wolf are sister species, so the ancestor of today’s dog was once closely affiliated to the wolves, which were the first domestic animals domesticated. The domestic dog, also known as the Cocker Spaniel or the Beagle, is probably the oldest domesticated breed of dog in the world. The earliest evidence of domestication came from around eleven thousand years ago, during the period when early man was building settlements and farming.
The various types of dogs have developed from several breeds and admixtures of these various types. The DNA of dogs reveals their relationship in terms of ancestry, but it is more than just this that determines the characteristics of the various breeds. In order to produce the most precise results, geneticists use several methods including genetic maps, marker breeds, hybridization, and gene flow. Marker breeds are crossbreeds between two breeds that have very similar traits, allowing the builder to produce a new breed. Hybridization involves adding gene sets from one breed to another to ensure the same characteristics between the new breeds are preserved.
There are four types of purebred dogs: the purebred American Hound, the purebred English Mastiff, the purebred Belgian Malinois, and the purebred Golden Retriever. The American Hound is the oldest breed in the world and remains the most popular today. The American Mastiff was recognized as the official breed standard for American Toy Therapy Association; this means that it is very likely that your own Golden Retriever belongs to this breed.
Scientists conducted a study found that there is less temperament in purebred dogs than in mixed breeds. The study also found that purebred dogs have a greater chance of living longer than other breeds because they are more balanced in nature. They also proved that dogs who belong to pure breeds have a longer life span than those dogs who belong to other breeds.
Mixed breeds are any dog breed that is a combination of two or more breeds. A mixed breed can be any dog breed that is of one breed and bred for another. A popular example of a mixed breed is the English Bulldog. Another example is a Chihuahua mix, like the Pugs. Examples of popular mixed-breed dogs include Irish Wolfhounds and Dobermans. However, a purebred dog breed such as the Boston Terrier still falls into a category of its own and has its own set of characteristics that distinguish it from other types of dogs.
The three categories above are just some of the many possible combinations of breeds that exist. There are probably even more types of dogs out there, just waiting to be discovered. As with any type of breed, they are all distinguished by distinct genetic structures and temperaments. A main article on this subject can be found below.