The origin and evolution of the domestic dog is a controversial issue for the scientific community, but a recent article in the journal Nature sheds light on this subject, and the dog DNA study revealed some interesting data about man’s best friend.
Several studies have tried to unravel the mystery of the origin of domesticated dogs, but none has given a definitive answer. However, a team of experts, led by the Swedish geneticist Peter Savolainen, believe that some 33,000 years ago, a population of wolves living in Southeast Asia diverged into two separate lineages, and the domestic dog appeared along one of those lineages.
“Nobody knows exactly what happened, but the favorite theory for many in the field is that this domestication was a collaboration between humans and wolves,” Savolainen, the study co-author, said.
“It might have started with the wolves coming closer to humans, living from the debris of food leftovers around human camps,” he explained. “And then those wolves that were least aggressive or that were best accepted by humans to come near, they got the best food and therefore a selective advantage compared to other wolves.”
Through an analysis of complete genomes of 58 dogs and wolves around the world, Savolainen suggests that the origin of domestication could be Southeast Asia about 33,000 years ago. According to the text published in the journal Nature, about 15,000 years ago a subcategory of ancestral dogs began to migrate to the Middle East, Africa, and Europe. While scientists believe that this dispersion was associated with the movement of humans, the first migration could have been initiated by the dogs themselves, due to environmental factors such as the retreat of glaciers that started about 19,000 years ago.
As indicated by the study, a group of migrant dogs returned to the north of modern China to breed with existing populations, which would be those that later would travel to America through the Bering Strait, between the regions of Siberia and Alaska.
The Guardian wrote, “the indigenous Chinese dogs revealed closer links to their wolf ancestors, and retained the greatest genetic variety, another indicator that the domestic canine began somewhere in East Asia.”
Based on the genetic analysis of the animals, the authors of this study found that dogs from Southeast Asia had higher genetic diversity than other dogs analyzed, and were more closely related to the grey wolves, which is why experts suggested that the domestic dog may have originated in Southeast Asia about 33,000 years ago.
Dog DNA study reveals the extraordinary journey of man's best friend https://t.co/0EccVC8ceR— Guardian Science (@guardianscience) December 15, 2015
Discovery News wrote that several possibilities could explain both the DNA evidence and the archaeological finds. One is that humans were migrating frequently and over long distances 33,000 years ago, and dogs followed. The second, according to Greg Hodgins (a researcher at the University of Arizona’s Accelerator Mass Spectrometry Laboratory), is that dog domestication happened repeatedly throughout early human history at different geographical locations. That would mean modern dogs have multiple ancestors, however, rather than a single common ancestor, as the new research indicates. The research concludes that both groups of dogs were crossed before spreading to the Americas.
“Our study, for the first time, begins to reveal a large and complex landscape upon which a cascade of positive selective sweeps occurred during the domestication of dogs,” the report states. “The domestic dog represents one of the most beautiful genetic sculptures shaped by nature and man.”
[Image via Christopher Furlong/Getty Images News]