Paleontologists and archaeologists determine that, about 60 million years ago, a small weasel-like mammal lived in and around what is now parts of Asia. It was called Miacis , the genus that became the ancestor of the animals known today as canids: dogs, jackals, wolves, and foxes. The Miacis did not leave direct descendants, but dog-like canids evolved from it.
About 30 to 40 million years ago, Miacis had evolved into the first dog, that is, the Cynodictis . This was a medium-sized animal, longer than it was tall, with a long tail and a fairly brushed coat. Over the millennia, Cynodictis gave rise to two branches, one in Africa and the other in Eurasia. The Eurasian branch was called Tomarctus and is the common ancestor of wolves, dogs, and foxes.
The domestication of the dog
Nearly 20,000 years ago, wolves were dangerous to humans. Their relationship was probably more one of vigilance to avoid being eaten than of friendship as it is now. However, over the years the domestication of ancient hunter-gatherers made dogs their faithful companions and household pets.
The timing and location of the dog’s domestication is less clear and has been a subject of significant debate, but there is strong genetic evidence that the first domestication events occurred somewhere in Central Asia before 15,000 years ago.
However, some genetic studies have suggested that wolves were domesticated 16,300 years ago to serve as livestock in China; and even other genetic studies have suggested that the domestication of dogs began more than 18,000 years ago in Europe. According to Robert Wayne, UCLA professor of ecology and evolutionary biology and lead author of one of these investigations, published in 2013 in Nature : “We found that instead of current wolves being closer to domestic dogs, ancient European wolves they were directly related to them. This makes the genetic record consistent with the archaeological record. Europe is where the oldest dogs are found ”.
To reach this conclusion, the researchers studied the mitochondrial DNA of the animals, very abundant in the ancient remains found. By comparing this ancient DNA with the modern genomes of 77 domestic dogs, 49 wolves and four coyotes, the researchers concluded that they were genetically grouped with ancient European wolves or dogs, not modern wolves from anywhere in the world. Thus, dogs are genetically derived from the ancient wolves that once populated Europe and are now extinct.
The first domesticated carnivores
“The wolf was the first domesticated species and the only large carnivore that humans have ever domesticated,” Wayne himself explained. But how did the carnivorous wolves and the ancient hunter-gatherers of Europe become inseparable companions?
According to the research, it is possible that the wolves preyed on the carcasses of the animals that the hunter gatherers ate and that, with the passage of time, they got closer and closer to them. This idea makes it possible to explain the genetic divergence between dogs and wolves. Those who followed the humans took advantage of their migrations, renouncing their territoriality and, therefore, reducing the possibilities of reproducing with territorial wolves.
In fact, there is an example of this process today. The only known migratory population of wolves in the tundra and boreal forests of North America follows the caribou (a species of reindeer) on its 1,000-kilometer migration. “When these wolves return from the tundra to the boreal forests during the winter, they do not reproduce with the resident wolves that never migrate,” explains the same researcher. “We believe that it is a divergent domestication and reproduction model of wild wolves and early dogs.”
Other estimates
Dogs dating from around 12,000 to 14,000 years ago are also suspected of coming from a small breed of gray wolf that inhabited what is now India. Thereafter, this wolf, known as Canis lupus pallipes, was widely distributed throughout Europe, Asia, and North America.
However, a genetic study comparing DNA from dogs and wolves that inhabit areas believed to have been centers of dog domestication suggests that modern dogs and wolves belong to separate lineages that share a common ancestor. It is also possible that some of today’s dogs are not descended from the wolf but from the jackal.
These dogs, found in Africa, could have given rise to some of today’s native African breeds. Another genetic study examining the migration of dogs to the Americas revealed evidence that dogs did not accompany the first humans to the Americas until just 10,000 years ago.
