Since the dog has become the companion animal par excellence in homes around the world, in addition to being a valuable helper in many of our tasks, it is normal to wonder about its origins, since when he shares our lives or what his ancestors are. The same applies to the cat, a species that has been living with human beings for less time, but is now also a highly valued pet. Few species, if any, present as many morphological variations as the dog, of weight or size, color and type of mantle, behavior, physical aptitudes or utility, among the several hundred breeds of dogs recognized today. It’s paradoxical that small changes in plumage color make two birds belong to different species and yet, a “Pekinese” of 3 or 4 kg weight, white and absolutely flat, belongs to the same species as an “Irish wolfhound”, for whom it does not ring a bell, a lebrel of gigantic size, 50 kg, dark color and stylized. 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 techniques of genetic markers of DNA, who shares our lives inside our homes is really a wolf, although that yes, something modified. It is paradoxical that the great enemy of the persecuted wolf, the fruit of our livestock tradition, the dog, is itself a wolf.
The domestication process is that by which a living being (animal or plant) sees its genetic structure modified as a result of its adaptation to the environment created by the human being. From an anthropological point of view, domestication has been considered as a milestone in the history of humanity, with an impact comparable to the control of fire or the wheel, and has influenced different civilizations by providing food, transportation, work and shelter. With the exception of the dog and the cat, most domestic species are herbivores, such as the horse, the cow or the sheep, but the wolf is the first animal to adapt to the coexistence with man. In addition they seem to be the only species, the dog and the cat, that came to domestication “voluntarily”,as they approached the villages, unlike the large herbivores, which were captured and reproduced in captivity.
Over the years, different specialists 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 assumed that dogs, due to their marked morphological and behavioural differences, came from one side of the golden jackal and the other from the wolf. Since the 80’s, the unique origin of the wolf began to be glimpsed, being subsequently confirmed by molecular genetics and DNA study. In 1997 in the prestigious journal “SCIENCE, was published a work 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 about 70 breeds of dogs, comparing it with that of wolves and other canids like coyotes and jackals of different species, existing a great similarity between the first (dogs and wolves) and great differences with jackals or coyotes. The dog and the wolf have a genetic resemblance of 99.8%. It seems that different varieties of wolves were involved in its origins, although they have 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 the coexistence with the human being and the consequent selection made. Therefore, another aspect of great interest as to the origin of the dog, is since when exists this bond of union between the primitive man and the dog (or domesticated wolf). Traditionally there was talk of a dog-man cohabitation 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 DNA studies. The ancient calculations were based on the first appearances of dog skeletons buried with people, about 15,000 years ago; but it is important to note that the process of domestication of the wolf, and its consequent morphological change to differentiate the skeletons, had to take many thousands of years. There are paleontological references of wolf bones along with hominids from over 200,000 years ago, It was impossible to determine precisely when these wolves were tamed and could be considered dogs. Domestication must have occurred in many parts of the world, and over time a large group of “modified wolves” was obtained, that were crossed and selected until the different breeds of dogs appeared. One aspect to highlight in this evolutionary process is that the dog is the only animal species that primitive man did not subdue by force in the process of domestication, as we mentioned before, but established a relationship of mutual interest; the primitive canids helped man by guarding the villages and collaborating in the hunt, taking advantage of these animals of the safety provided to them by man in front of other predators and obtaining easy food in the waste and scraps of hunting. During domestication, the less aggressive and more tolerant specimens with contact with man were probably selected. It can be said that in the entire history of today’s human being (Homo sapiens sapiens) the dog, or if we prefer it, the modified wolf, has always been present. This exciting origin of our most beloved animal, endorses the pact of friendship and the ties that unite man, primitive or current, and the dog.
For its part, the domestic cat comes from the “African wild cat” (Felis líbica), without the participation of the European wildcat, despite its physical resemblance. Domestication appears to have occurred in the Neolithic era, some 9,500 years ago, in the Nile Delta and Mesopotamia. The wild ancestor is a small feline, with solitary and very territorial habits, adapted to a semi-arid climate, with large hunting areas. The most accepted evolutionary theory indicates that those specimens more tolerant with the human being, and even more tolerant among them, approached the villages. This Neolithic era coincides with the transformation of the man “hunter and gatherer” in incipient “farmer and farmer”,which initiates grain storage and the consequent rodent concentration. The most tolerant cats found a new ecological niche in the proximity of the human being, which provided them with protection and fundamentally a greater abundance of prey. With the passage of time these animals reproduce with each other would give place to the domestic cat, which would expand all over the world.