Dogs seem to have descended from wolves twice. At least this follows from a study published recently in the journal Science. After analyzing the genomes of modern dogs and wolves, as well as their distant ancestors, scientists changed the idea of the origin of our four-legged friends.
From earlier works it was known that dogs were domesticated about 10,000 years ago in Central, East Asia and Europe. A new study covered the genomes of dogs that lived even earlier.
“We wanted to find out when and where the dogs were domesticated,” says co-author of the study Laurent Frantz, an evolutionary geneticist from Oxford.
Frantz and his colleagues decryptedthe mitochondrial DNA sequence of 59 European dogs living 3,000-14,000 years ago. Scientists also analyzed the genome of a dog that was found in a burial site made 4,800 years ago in Ireland. Researchers have compared ancient genomes with the genomes of hundreds of modern wolves and dogs of 48 breeds.
Phylogenetic analysis revealed twobranches on the genetic tree of dogs. The latest fork separates Sarlos’s wolf dog from the main trunk, a breed bred in the Netherlands in the 1930s by crossing a German shepherd and a wolf.
The division turned out to be more curious.East Asian and West European genomes, which occurred 6400-14 000 years ago. According to scientists, the discrepancy occurred a few thousand years after the first appearance of dogs in Eurasia. Modern breeds such as huskies and Greenland sled dogs have ancestors from both regions.
Researchers explain the separation of genomes by two independent cases of domestication, which took animals from different populations.
“This is not the final conclusion, we need more information. However, data from genetics and archeology testify in favor of the dual origin of the domestic dog, ”said Frantz.
The hypothesis of scientists is confirmed by the fact that in the regionno remains of ancient domesticated dogs were found between Western Europe and East Asia. In all likelihood, dogs came with people from Asia to Europe.
Adam Boyko, geneticist from CornellUniversity of Veterinary Medicine in Ithaca, NY, doubts that the dog has been domesticated twice. However, he considers Frantz's hypothesis promising. According to Boyko, scientists needed to study the DNA of more remains, such as those that were found in Ireland.
Pontus Skoglund, a geneticist at Harvard Medical School (Boston), is confident that the discovery of Frantz requires further research.
“Learning more about the origin of moderndogs, we open a window to the ancient history of man. Apparently, the domestication of a dog was one of the first innovations in human culture, ”said Skoglund.