Dogs Diverged Into Breeds 11,000 Years Ago, Study Reveals

A recent study suggests that domestic dogs began to diversify in size and shape thousands of years ago, not just hundreds. Researchers from ...

A recent study suggests that domestic dogs began to diversify in size and shape thousands of years ago, not just hundreds.

Researchers from the University of Exeter have examined hundreds of ancient dog remains covering the past 50,000 years.

They have identified the remarkably early period when dogs started to show physical differences – approximately 11,000 years ago.

The results contradict 'long-held beliefs' that dogs have varied appearances solely due to selective breeding since the Victorian period.

The scientists do not reject the fact thatthe Victorians played a major role in what we now call dog breeds. 

However, their research indicates that the variety of physical traits in dogs extends back further in time than previously believed.

"These findings emphasize the long-standing connection we have had with dogs," said Dr. Carly Ameen, the study's author from the Department of Archaeology and History at Exeter.

Variety in dogs is not solely the result of Victorian breeders, but rather a heritage that spans thousands of years of mutual evolution with human cultures.

Collaborating with professionals in France, the researchers examined 643 contemporary and ancient skulls from the canid family.

The specimen, which is 50,000 years old, comprised known breeds, stray dogs, and wolves.

The scientists also developed 3D models of the skulls to gain a deeper understanding of their dimensions and structure.

Findings revealed a variety of skull shapes and sizes in domestic dogs from 11,000 years ago, shortly after they separated from wolves.

At that time, the skull shapes were not as extreme as those seen in modern breeds like pugs or bull terriers, according to Dr. Allowen Evin from CNRS in France.

"But Mesolithic and Neolithic dogs already showed roughly half of the total skull variation seen in modern dogs," she said to the Daily Mail.

This indicates that primitive dogs exhibited significant differences in skull size and shape.

The first fossil recognized as belonging to a domestic dog was discovered at the Veretye site in Russia, dated to approximately 11,000 years ago.

Canine diversity milestones

• 11,000 years agoDogs start to exhibit variation in size and appearance
• 9,700-8,700 years ago: General decrease in canine skull size
• From 8,200 years ago: Increased diversity in skull morphology
• From 7,700 years ago: Greater diversity in the size of dogs (more variation in terms of dog size)

 

The group also discovered ancient dogs in America around 8,500 years ago and in Asia (7,500 years ago) that had 'domestic skull shapes' – generally shorter and broader in comparison to wolf skulls.

Following that, greater diversity arose quite rapidly, which probably indicated the dog's wide range of functions in ancient human communities, spanning from hunting and herding to being a companion.

In general, dogs have experienced remarkable physical variation over the last 11,000 years, according to Dr Evin.

"Modern dog breeds now vary from chihuahuas to mastiffs and from flat-faced pugs to long-nosed greyhounds — shapes much more extreme than any seen in the archaeological record," she said to the Daily Mail.

Dr. Dan O'Neill, a professor of animal epidemiology at the Royal Veterinary College, who was not part of the research, concurred that the variety of the dog's physical form as a general idea has existed for thousands of years.

Nevertheless, he emphasized that the selective breeding of extreme and unhealthful body types is a relatively new development, beginning around the late 1800s.

Since the Victorian period, dogs have been intentionally bred to enhance negative traits, resulting in various breeds designed to set them apart and support a commercial dog market.

Since then, these characteristics—like the long bodies of dachshunds and the flat faces of pugs—have become increasingly pronounced.

Flattened features and overly constricted nasal passages limit air intake, causing breathing difficulties, particularly during activities like walking or chasing a ball.

Meanwhile, dogs with sausage-shaped bodies often experience serious back issues because of their long spine and curved, short legs, which may result in them being unable to walk.

"What occurred in Victorian England was the creation of the idea of dog breeds and the official written explanations of how a breed should appear," Dr. O'Neill said to the Daily Mail.

This was done to establish a benchmark for comparing dogs in a dog show.

This is a recent trend, and it built upon the thousands of years of physical variation to produce all these new breeds that appeared around that time in the late 1800s.

Dr. Evin emphasized that the research concentrated solely on skull structure, rather than factors such as fur color, body dimensions, or other physical characteristics.

"But we can certainly determine when skull characteristics differ from the wolf's pattern to create what we refer to as a 'domestic' form," she added.

The study was released today in the publicationScience. 

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