The diversity of our dogs dates back to the Stone Age

If you, like me, have a pampered, lazy dog ​​who likes cheese-flavored treats, the fact that your pet’s ancestors were wild predators may seem unfathomable.

But a major new study suggests that his physical transformation from wolf to couch-hogging furball began in the Middle Stone Age, much earlier than we thought.

“When you see a Chihuahua, it is a wolf that has been living with humans for so long that it has been modified,” says Dr. Allowen Evin of the University of Montpellier, principal investigator of this study.

She and her colleagues discovered that the transformation of our pets advocated by the Victorians through selective breeding actually began more than 10,000 years ago.

In an article published in the journal Science, this international team of researchers focused their attention on prehistoric canine skulls. For more than a decade, they collected, examined and scanned bones spanning a period of 50,000 years of canine evolution.

They created 3D digital models of each of the more than 600 skulls they examined (and compared specific features of ancient and modern dogs) and their wild relatives.

This revealed that, almost 11,000 years ago, just after the last ice age, dog skulls began to change shape. While there were still thin, wolf-like dogs, there were also many with shorter snouts and wider, stockier heads.

Dr Carly Ameen from the University of Exeter, another lead researcher on this project, explained to BBC News that almost half of the diversity we see in modern dog breeds today was already present in dog populations in the mid-Stone Age.

“It’s really surprising,” he said. “And it starts to challenge ideas about whether or not it was the Victorians, and their kennel clubs, who pushed this.”

Dogs were the first domesticated animals. There is evidence that humans have coexisted closely with canines for at least 30,000 years. Where and why that close association began remains an enigma.

This study has revealed some of the first physical evidence of dogs transforming into the diverse range of pets, companions and working animals we know today. And the digital scans of the skulls the researchers studied will allow them to answer more questions about the evolutionary driving forces behind domestication.

Some researchers have suggested that humans and wolves came together almost by accident, when wolves moved to the outskirts of hunter-gatherer communities to forage.

More docile wolves would get more food, and humans gradually came to rely on wolves to clean up messy carcasses and raise the alarm if a predator approached.

As for why that ultimately changed the dogs’ physical appearance, Dr. Ameen said there were probably several reasons. He didn’t rule out our ancestors’ preference for square heads and cute, flat noses, but explained: “It’s probably a combination of interaction with humans, adaptation to different environments, adaptation to different types of food, all of which contribute to the kind of explosion of variation that we see.

“It’s hard to tease out which of them might be the most important.”

For tens of thousands of years, our human history and that of our dogs have been intertwined. In another article in this issue of Science magazine, a research group led by scientists in China studied the ancient DNA of dogs that lived between 9,700 and 870 years ago, at sites in Siberia, the central Eurasian steppe, and northwest China.

They concluded that the movement of domestic dogs through that region often coincided with migrations of people: hunter-gatherers, farmers and herders. Our dogs have traveled alongside us and been integrated into our societies for thousands of years.

I can’t say that my own stubborn and disobedient terrier provides me with any of the benefits that the first domesticated wolves provided to our ancestors. But I can see why, as the research suggests, once a dog showed up to pick up some leftovers, there was no turning back.