The Diversity of Dogs

How Dogs Became the Most Diverse Land Mammals on Earth

Did you know that dogs are the most diverse species of land mammals on the planet? That’s right - our four-legged friends hold the title as the most genetically varied group of all mammals on land. When we consider that the Toy Poodle and Great Dane are classified as the same species, it starts to make a bit more sense. In fact, the largest dog breed in the world is roughly 40 times larger than the smallest, which is just one example of the incredible genetic variation among dogs.

When the earliest dogs made their initial split from wolves around 20,000 – 30,000 years ago and formed their own distinct species, Canis Lupus Familiaris, the world was a very different place. Vast sheets of ice still covered much of the earth and nomadic people travelled the harsh landscapes in search of food. Scientists believe these ancient dogs followed alongside their human counterparts, eventually forming symbiotic relationships in which we benefited from each other’s presence.

As dogs travelled in different directions with different groups of people, over time their physical and behavioural characteristics would begin to change to adapt to their new surroundings. For example, the Northern Spitz-type breeds would develop thick, well-insulated coats to withstand arctic temperatures while those in the Middle East and North Africa would have shorter, sleeker coats meant for hot, dry climates. These early dogs would have crossbred with other dogs, wolves, now-extinct canines, and other wild canids along the way, which would have established the basis of their branching genetic diversity.

The ancient dogs of old would look quite different from the dogs we’re used to today; However, there are still a few primitive breeds in existence that give us a good indication of what dogs from the past would have been like.

Primitive Breeds, sometimes referred to as Aboriginal Dogs, Landrace Breeds, Pariah Dogs, or Village Dogs are extremely old breeds that have remained relatively unaffected by human interference and have retained many of their original physical characteristics. These dogs exist all over the world, with nearly every continent claiming at least a primitive breed or two. The New Guinea Singing Dog (NGSD) and the Australian Dingo are two prime examples of primitive breeds that still live largely independently from people.

Although the American Kennel Club only recognizes about 200 dog breeds, there are approximately 350 breeds known to exist around the world. Of those, only a handful are considered to be truly ancient breeds. When we say “ancient” we’re not only referring to how old the breed is but also how strong their genetic relation is to their ancestor, the Grey Wolf.

Aside from the handful of ancient breeds mentioned above, essentially all other breeds came into existence within the past 400 years when humans began selective breeding processes to develop specific features for specific tasks. Depending on the jobs at hand, people began crossing different types of dogs in an effort to retain certain traits while eliminating others. Different jobs would require different physical and behavioural traits, and so humans set out to craft and create the perfect dog for every job.

For example, after widespread farming was implemented, dogs were bred to help protect and herd livestock. These dogs would need to be fast, agile, independent, and intelligent (think of the Collie family!). In even earlier times, people bred large, strong mastiff-type dogs of war that could withstand injuries and fight fiercely on the battlefield. Many people relied on the dog’s impeccable sense of smell to help with tracking and hunting, and so various hound breeds were developed to help put food on the table.

From vermin hunting and guard dog duty to tracking, hunting, retrieving, and even pure companionship, people have played a significant role in shaping the development and genetic diversity of dogs. In fact, so many different breeds - and sub-categories of each - were created that canine group classifications came into play to make it easier to categorize this ever-growing number of breeds.

Not only were group classifications introduced, but since the 1800s clubs dedicated entirely to our four-legged friends also came into existence. The first of these clubs, simply named “the Kennel Club” (KC) was established in the United Kingdom in 1873, with the American Kennel Club (AKC) forming shortly afterward in 1884.

From a few ancient, primitive breeds that roamed the earth to hundreds of different breeds ranging from 2 pounds to 200, it’s safe to say the dog’s journey from Canis Lupus to Canis Lupus Familiaris has been a long and interesting one.