Man's best friend descended from European wolves
A new study out Thursday comparing DNA from modern canines to ancient fossils suggests that today's pets descended from now-extinct populations of wolves in Europe.
Man's earliest best friends likely scavenged bones from scrap piles left behind by hunter-gatherers, said the report by international researchers in the journal Science.
The bolder the wolf, the more he would be able to eat and the more loyal to humans he would become.
Scientists now believe this process of domestication likely began as many as 19,000 to 32,000 years ago.
"All modern dogs have a very close relationship to ancient dogs or wolves from Europe," lead author Olaf Thalmann, a researcher at the University of Turku in Finland, told AFP.
Traits traced back 30,000 years
The team analysed the mitochondrial DNA of 18 prehistoric canines, eight dogs and 10 wolves, and compared them to 77 mitochondrial genomes, showcasing traits inherited from the mother, from dogs from all over the world.
The ancient samples came from Russia, Ukraine, Central Europe, the United States and Argentina, Thalmann said. Some were more than 30,000 years old.
The modern DNA from dogs and wolves spanned the globe, from Israel to China, Sweden to Mexico.
"The oldest domesticated dog material came from Europe," said co-author Robert Wayne, a professor in the department of ecology and evolutionary biology at the University of California Los Angeles.
However, other researchers say the matter of who tamed dogs first and where it happened is far from settled.
A separate team of researchers published a study in Science in 2002, saying that modern dogs came from southern China.
"Our data points to origins in China and I am still pretty sure that is the place," said Peter Savolainen, an associate professor at the Royal Institute of Technology in Sweden.
Savolainen said the study by Thalmann and colleagues lacks samples from important parts of the world, namely the Middle East and China.
"If you are looking for the origins of dogs and you only have samples from Europe, then of course it must be Europe," he told AFP.
Dogs out of China
Savolainen said that much like the "Out of Africa" theory that says humans originated in Africa and migrated elsewhere, dog history follows an "Out of south China" scheme.
"You see several branches that are unique among dogs in south China and you don't see them anywhere else," he said.
Asked about the criticism from China theorists, Thalmann countered that his team used more complete DNA sequencing and older samples that show Europe was indeed the place where it all began.
Still, the matter is far from settled, Thalmann told AFP. More research in the years to come may reveal more on the topic, perhaps through the discovery of more fossils, or a more complete look at the genetic data.
In the meantime, most experts agree that early dogs became a part of human life long before the development of agriculture and farming societies.
Little is known about the people who domesticated them, or how they did it.
Wolves befriended humans
But Savolainen believes that wolves took the lead when it came to befriending humans, at least initially.
"They approached human camps and ate from the scrap heaps and those who dared come closer would get most of the food and they would have an evolutionary advantage," he told AFP.
"So with each generation they would sort of tame themselves to get accustomed to humans. That is everybody's favorite theory, and I think it is a nice theory as well."
As some wolves relied less on killing prey and more on eating scraps, their snouts gradually grew shorter. They likely followed human groups whenever they picked up and moved camps.
Then, about 10,000 to 15,000 years ago, the closer friendship truly began.
"At some point, people and wolves really started interacting and humans took over the rest of the domestication process," said Savolainen.
Thalmann said his team's evidence suggests dogs likely accompanied European explorers to the New World.