It’s a myth that the Victorians created modern dog breeds – we’ve uncovered their prehistoric roots.

Domestic dogs are among the most diverse mammals on the planet. From the tiny Chihuahua to the Great Dane, the flat-faced Pug to the long-haired Borzoi, the sheer range of canine shapes and sizes is astounding.

We often attribute this diversity to a relatively recent phenomenon: the Victorian kennel clubs that first emerged over 200 years ago. These clubs are generally credited with formalizing the selective breeding that created the hundreds of modern breeds we recognize today.

But our new research, published in Scienceshows that this is just the latest chapter in a much larger story. Dogs were already significantly diverse in the size and shape of their skulls 10,000 years ago, long before canal clubs and pedigrees.

This finding challenges the idea that only domesticated body types are the only ones we’ve seen in dogs. Instead, our research shows that early dogs took to domestication immediately. Later, unusual forms were developed.

First there is the search for the dogs

For decades, paleontologists and geneticists have been trying to answer a deceptively simple question: When did wolves become dogs?

The history of human interaction with wolves is a long one, stretching back to the last Ice Age, perhaps even 30,000 years ago. But the exact time to breed a dog is uncertain. What makes dogs particularly special is that they were the first generation of humans before any plants or livestock. Yet despite decades of research, the first dogs continue to elude us.

Part of the challenge is the similarities between wolves and dogs. Even today, some modern dog breeds resemble wolves. This makes it particularly difficult to trace their domestication in the archaeological record. By using a technique called geometric morphometrics—a method of mapping and measuring shape variation in three dimensions—we can track subtle changes in shape over time from 3D models of archaeological skulls.

We analyzed 643 skulls of ancient and modern dogs and wolves, spanning 50,000 years, primarily in the Northern Hemisphere, to track the emergence and diversification of domestic dogs over time and space.

What we found was surprising: the earliest skulls with clearly domesticated skull forms in our dataset were from the Mesolithic site of Verete, Russia, dating to about 11,000 years ago.

By this time, dogs had not only diverged from wolves in terms of skull shape, but had begun to diversify among themselves. These early dogs were not all alike, but instead exhibited skulls of varying sizes and shapes, perhaps reflecting the influence of local environments, population histories, and human preferences.

In fact, some early dogs exhibit skull shapes not found in any modern species, indicating lineages and shapes that have since died out. Although we don’t see some of the extreme forms of skull shape that we see today (like pugs or bull terriers), the variation we see through the Mesolithic is already the total amount of variation we see in modern breeds.

This echoes genetic studies that show deep divisions in early dog ​​populations. By the Neolithic (about 8,800–5,000 years ago), dogs had already formed regionally distinct lineages in Europe, the Near East, and Asia. Some of these lineages survive into modern generations, while others seem to have become extinct, possibly replaced or degraded by human movements.

Rough household

Our findings complement a growing body of genetic and archaeological evidence suggesting that dog domestication was a long and regionally diverse process. Ancient DNA research has shown that large dog lineages diverged as early as 11,000 years ago, indicating that the process of domestication began much earlier.

The exact time is still debated, with some research pointing to the cessation of human-canid relationships as early as 30,000 years ago. However, none of the 17 late Pleistocene (126,000 to 11,700 years ago) skulls in our study were of domestic dogs that we examined, suggesting that it cannot go back much further than that. Of course, early dogs had to closely resemble wolves, and it is possible that early dogs retained wolf-like skulls for generations, but how long is unknown.

There’s still a lot we don’t know. To deepen our understanding, we need more samples from the critical window between 25,000 and 11,000 years ago, especially in the regions in question such as Central and Southwest Asia. What this work has revealed, or perhaps reinforced, is a much older story of evolution between humans and dogs that itself began after domestication.

After all, dogs are a mirror of human history. Their story is intertwined with ours, in the form of shared migration, changing environments and developing societies. As the first domesticated species—and still our most enduring companions—dogs offer a unique window into how humans have shaped the natural world and how the natural world in turn has shaped us.

This article is reprinted from The Conversation under a Creative Commons license. Read the original article.