A new study published Wednesday in the journal Science suggests that dogs were domesticated twice in Europe and Asia by two entirely different groups of people in an era without global communications.
Based on the genetic and archaeological evidence, the team of international researchers wrote in the paper that ancient people in Western Europe and Asia realized that wolves should be domesticated about 10,000 years ago. If they came to the same conclusion without being able to watch videos or images from each other’s practices on social media, then it would be safe to say that dogs and humans have always been inevitably meant to be together.
The team also found that at some point between 6,400 and 14,000 years ago, an eastern dog population that had moved westward along with their human pals replaced to some degree the group of dogs native to Western Europe.
The study authors examined DNA sequences from the remains of 59 ancient European dogs ranging from 3,000 to 14,000 years old. They also had access to a full genome taken from the fossil of the inner ear bone of a dog that dates back to 4,800 ago. The fossil was found at Ireland’s Newgrange grave complex and the researchers compared all these fossils to DNA from a large number of modern dogs.
The paper states that there was a significant division between the East Asian and modern European dogs and knowing the age of the medium-sized Newgrange dog allowed the study authors to estimate the genetic mutation rate, according to researcher Greger Larson, an Oxford evolutionary biologist.
The calculations show that the East-West split occurred between 6,400 and 14,000 years ago, which could lead to the conclusion that dogs were first domesticated in East Asia and then migrated West with their new human friends.
However, the oldest archaeological fossils of dogs found in European territory are at least 15,000 years old, meaning that dogs were hanging around in Europe before the split took place. Even though both groups had a common ancestor between 14,000 and 6,500 years ago, the authors found that two different populations of dogs lived in both territories during the Paleolithic.
Moreover, if massive populations of dogs had migrated from East to West, then they would have left many dog fossils in the area that is in the middle. The study reveals that concrete evidence proves there were dogs in Eastern Eurasia dating back to 12,500 years, whereas there is evidence of dogs dating back to 15,000 years in Western Europe.
Lead author Laurent Frantz said there is no evidence of any dogs earlier than 8,000 years old in the middle.
“If dogs were domesticated only once and transported from east to west, we should find these gradients, and we can’t find it,” added Frantz, who is an evolutionary geneticist at the University of Oxford.
The East-West dispute over the origins of dogs might be coming to an end
Greger Larson says he hopes the study findings will help solve the long-standing scientific debate between people who argue that the beloved animals were first domesticated in a region rather than the other.
“Maybe the reason there hasn’t yet been a consensus about where dogs were domesticated is because everyone has been a little bit right,” Larson said in a statement, as reported by the Los Angeles Times.
On the other hand, Frantz pointed out that such a phenomenon of animals being domesticated twice in different regions had happened with pigs, too.
There is archaeological evidence suggesting that pigs were domesticated once in China’s Mekong Valley and once in Anatolia, which is currently known as a region located in Turkey between the Black, Mediterranean, and Aegean seas, according to Science Magazine.
In a study published by Frantz in Nature Genetics last August, he and his colleagues conducted advanced computer analyses of 103 complete sequenced genomes from wild boars and domesticated pig breeds from across Europe and Asia.
Martien Groenen, his adviser by that time and animal genomicist of Wageningen University, had sequenced the same genomes and had collected extra, though less complete, genetic data from 600 different domesticated and wild pigs as he was conducting a separate study.
Because Europe’s modern pigs are mixes from a variety of wild boar populations, the researchers came to the conclusion that some ancestors emerged from an extinct group or another ghost population in central Eurasia. Pigs might have been herded from place to place and mated with this group. Besides, it is likely that Asian pig blood joined the mix when Europeans imported Chinese pigs in the 1800s as an attempt to enhance their commercial breeds.
All of this research serves as a clear indication that the process of animal domestication is far more complex than most scientists believed it was, given the multiple factors and places that must be taken into account to discover the true origins of the species and their relationship with humans.
Source: Los Angeles Times