Humans first made dogs their best friends in prehistoric Europe, where groups of hunter-gathers learnt to tame dangerous wolves into companions between 19,000 and 32,000 years ago, scientists said on Thursday.
The new research, based on analysis of DNA fragments from fossils of ancient wolves and dogs, confounds earlier theories that dogs were originally domesticated in the Middle East or East Asia.
Experts generally agree that dog training started out with a few gray wolves hanging around human encampments in the hope of picking up scraps. Over time, humans accepted them, perhaps initially as guards or hunting partners, and taught them to be useful companions.
Where and when this happened, however, has been a matter of controversy.
Now Olaf Thalmann, from Finland's University of Turku
, and colleagues believe they have placed initial doggy taming firmly in Europe after finding that modern dogs' DNA most closely matches that of either ancient European canines or modern European wolves, but not wolves outside Europe.
“We're pretty sure that Europe played a major role in the domestication of the dog,” Thalmann, whose research was published on Thursday in the journal Science, said in an interview.
The fact that dogs were domesticated so early in Europe means they joined human society when people were still hunter-gathers rather than farmers.
As a result, Thalmann believes the first “proto-dogs” might have taken advantage of carcasses left on site by early human hunters, as well as helping them catch prey and providing defense against competing predators at kills.
The genetic analysis carried out by his team was based on mitochondrial DNA - a common tool for tracking ancestry - that was extracted from fossils of eight ancient dogs and 10 wolves.
This was compared to genetic samples from 130 modern dogs and wolves, leading the researchers to conclude that the first dogs originated in Europe from a population of gray wolves that is now extinct.
Mitochondrial DNA, which is passed from mothers to daughters, changes little from generation to generation. By studying it, scientists are able to calculate when populations or species start to separate genetically. But it does not provide a complete genetic picture, leaving some uncertainty.
While the early dogs that socialized with tribes of hunter-gathers would have looked very similar to wolves, the vast variety of breeds evident around the world today is a function of more recent human activity, experts believe.
“Modifying a wolf into a Chihuahua is clearly a long process and most of the active breeding has happened in just the last few hundred years,” Thalmann said.