Domestic dog was created due to human needs. It was created to guard the household, other animals and helped during hunts. However, the selection and interbreeding practice very quickly got out of hand.
Humans realized that it is not such an easy task to train a dog to attack whenever they wish or to make it unnaturally and excessively aggressive; to wag its tail whenever it approaches someone or to bring a stick no matter how many times we threw it. This is why they turned to creating breeds that are more capable of completing certain tasks.
With Industrial Revolution (1760–1820/40) came the progress in engineering field and making humans turning away from nature. Technical innovations made many domestic dogs an excess. Instead of these circumstance making humans appeased – making them stop creating new breeds – the opposite happens. The number of breeds is getting bigger since the scientific progress is a good base and propulsion for it.
Humans force features that would have been erased by nature because they like them, which brings serious consequences. During this process, certain instincts are obtained while natural are lost. This is why some breeds are fearless and rash – bold, not brave animals. Some are aggressive and not stable. Some are hyperactive and not balanced... The less purebred a dog is, the more aggressive signals will it carry, but more conciliatory signals as well, as the purpose of dog communication is to avoid physical confrontation. On the other hand, purebred dogs will carry more submissive signals, or more aggressive ones, or even be less aware of other dogs' signals. Beside this, physical appearance that is being insisted on, very often badly affects movement, breathing and other health issues.
British aristocracy, in desire to further itself from middle class, introduced a concept of pedigree. It strived in preserving pureblood animals, those specimens with good and healthy appearance – by their standards, of course. Dog shows started to be organized in order to promote purebred dogs.
Changes in appearance that are being set by the dog show standards are different, usually – shorten snouts, more wrinkles especially around the head, enlarged heads and neck area, elongated ears, but shape of the abdomen, length of legs and many others too.
There is more than 800 breeds today, and this number is still raising. Out of this number, 400 is acknowledged by kennel organizations. The rest are in process of standardization, even though, in some countries, they are already being regarded as breeds.