We share a fragment of this very interesting article published by the Official College of Veterinarians of Madrid, about the origin of the dog. You can access the full article in the link at the bottom of the page.
Taking into account that the dog has become the companion animal par excellence in homes around the world, in addition to being a valuable assistant in many of our tasks, it is normal that we wonder about its origins, since when it shares our lives or what are your ancestors.
Few species, if any, present as many morphological variations as the dog, in weight or size, color and type of coat, behavior, physical aptitudes or utility, among the several hundred breeds of dogs recognized today. It is still paradoxical that small changes in the color of the plumage make two birds belong to different species and that nevertheless, a «Pekingese» weighing 3 or 4 kg, white and absolutely flat, belongs to the same species as a «Irish wolfhound», for those who are not familiar, a greyhound of gigantic size, 50 kg, dark and stylized in color. From the beginning there have been different theories about this origin of our dogs, but as we will see later, in the light of current knowledge and based on modern DNA genetic marker techniques, whoever shares our lives inside our homes is really a wolf, although yes, somewhat modified. It is still paradoxical that the great enemy of the persecuted wolf, the fruit of our livestock tradition, the dog, is in turn a wolf.
The domestication process is one by which a living being (animal or plant) sees its genetic structure modified as a result of its adaptation to the environment created by humans. From an anthropological point of view, domestication has been considered a milestone in the History of Humanity, with an impact comparable to the control of fire or the wheel, and it has influenced different civilizations by providing food, transportation, work and coat. Except for the dog and the cat, most of the domestic species are herbivores, such as the horse, the cow or the sheep, however the wolf is the first animal to adapt to coexistence with man. They also seem to be the only species, the dog and the cat, that came to domestication «voluntarily», when approaching the villages, unlike the large herbivores, which were captured and reproduced in captivity.
Over the years, different specialists have proposed theories about the origin of the dog as a domestic animal, making it come from crosses between different wild canids. The prestigious ethologist Konrad Lorenz, supposed that the dogs, due to their marked morphological and behavioral differences, came on one side from the golden jackal and on the other from the wolf. Already from the 80s the unique origin began to be glimpsed from the wolf, being confirmed
later by molecular genetics and the study of DNA.
In 1997 in the prestigious magazine «SCIENCE, a work was published that definitively confirms that» all current dog breeds have only one ancestral species: the wolf. The study is based on the determination of the DNA of some 70 breeds of dogs, comparing it with that of wolves and other canids such as coyotes and jackals of different species, with a great similarity between the former (dogs and wolves) and great differences with jackals or coyotes. The dog and the wolf have a genetic similarity of 99.8%. It seems that different varieties of wolves participated in its origins, although they are yet to be determined. Despite their physical resemblance, the genetic differences between wolves and coyotes are very large, indicating that they separated as distinct species more than a million years ago, unlike what happens between wolf and dog.
The great differentiation between wolves and dogs is the result of coexistence with humans and the consequent selection made. For this reason, another aspect of great interest regarding the origin of the dog is how long has this bond between primitive man and dog (or domesticated wolf) existed.
Traditionally, there was talk of a man-dog coexistence of about 10,000-15,000 years, but more recent theories confirm a much older relationship, in the Middle Palaeolithic, at least 40,000 years ago, based on evolutionary studies of DNA. The old calculations were based on the first appearances of skeletons of dogs buried next to people, about 15,000 years ago; but it is important to bear in mind that the wolf domestication process, and its consequent morphological change that allows the skeletons to be differentiated, had to take many thousands of years.