Posted 30 октября 2020, 13:53
Published 30 октября 2020, 13:53
Modified 24 декабря 2022, 22:36
Updated 24 декабря 2022, 22:36
The results of a study of the remains of dogs between 800 and 11,000 years old, found in Europe, the Middle East and Siberia, are published in the journal Science.
As scientists discovered, 11,000 years ago, by the end of the last ice age, there were already at least five genetically distinct groups of dogs on Earth. However, despite their differences, all of these groups appear to have descended from a common ancestor, suggesting that domestication, which most likely took place 20,000 years ago, began with a single extinct population of ancient wolves.
One of the most interesting discoveries is that although dogs are descended from wolves, no new wolf DNA has entered the genomes of dogs since this separation happened (over 15,000 years ago). This fact puzzles even researchers: after all, people have repeatedly crossed dogs and wolves. In this case, modern wolves reveal the presence of canine DNA. As scientists suggest, the fact is that a human-oriented dog and a wolf are different creatures by definition. Dogs with a "wolf character" are found, however, they do not stay for a long time among their relatives, do not integrate into the population.
Despite all the efforts of breeders, modern dog breeds are genetically much closer to each other than dogs of antiquity, which were much more diverse in this sense. This diversity began to disappear about 4,000 years ago, long before work began on creating new breeds. All European dogs appear to have descended from the same group of ancient European dogs, and in dog breeds around the world, geneticists see this DNA - presumably because during the era of colonialism, these dogs spread everywhere. However, some breeds have genetic similarities to other ancient predecessors.
For example, Chihuahuas of Mexican origin have 4% of their DNA from Ice Age dogs from ancient America. A similar story with the Siberian Husky: although it carries the DNA of modern European dogs, it also has genes from Ice Age dogs from Russia. Basenji descended from ancient dogs from the Middle East. As for breeds such as the German Shepherd Dog and the Irish Terrier, they are in equal parts a cross between ancient groups from the Mediterranean and Northern Europe: it is likely that when the first farmers came to Europe, they brought their dogs with them, and they mixed with dogs that already lived there.
Scientists used the genetic data of humans and dogs to understand how much their movements around the world coincided. The results showed that they moved together frequently, but not always. Apparently, sometimes, leaving for a new place, people did not take their dogs with them, and sometimes they preferred the breeds that were found in a new place. Changes in the human and canine genomes often occurred independently of each other.
For example, migration from the steppes to Europe altered human genomes, but almost did not affect the genomes of dogs. Conversely, migration from the steppes to the East left an imprint on the genomic history of dogs, but not on humans.