All About Dog Breeds

Podcast Transcript

When looking at a dachshund and a great dane, it is hard to believe that these dogs trace back to the same ancestors. Yet, this is true!

Through centuries of domestication and selective breeding, humans have transformed dogs into the most diverse mammal species known today.

Yet, despite the incredible diversity in dog breeds, remarkably, they are all members of the same species.

Learn about the development of dog breeds and why there are so many on this episode of Everything Everywhere Daily.

To understand the creation of dog breeds, you first have to understand the domestication of dogs.

In a previous episode, I covered the domestication of dogs, so if you want a more thorough explanation, I recommend listening to that. For the sake of this episode, I will provide a short summary.

Dogs hold the distinction of being the first species humans domesticated and the only large carnivorous animal to undergo this process.

All dogs are descended from an ancient wolf population, and they are considered the same species, classified under the scientific name Canis lupus familiaris.

That means that every domesticated dog, regardless of size, shape, or color, is the same species.

You can tell that dogs are the same species because they can breed with other dogs. In scientific terms, a ‘species’ is often defined as a group of living organisms that can interbreed and produce fertile offspring.

While there are some exceptions to this rule, it does apply to dogs.

That means a chihuahua and a great dane can interbreed with each other….although in that case, there could be issues.

Scientists debate the timing of dog domestication, but most research dates it to 12,500 to 15,000 years ago, though some researchers claim it could be as early as 130,000 years ago.

Dogs were the only species domesticated by hunter-gatherers, and the reason as to why is debated, but the theories are as follows:

People domesticated dogs to help with hunting.
Wolves scavenged at human waste sites, making them more accustomed to people.
Or during the ice age, humans fed their surplus of lean meat to dogs, eliminating the natural competition between the two species.

Regardless of how domestication occurred, the two species evolved alongside each other, and as they evolved, so did new practices, including selective breeding.

Selective breeding is the reproduction of different plants or animals for specific traits.

For dogs, selective breeding has occurred for thousands of years across different continents, countries, and cultures.

Unlike many other domesticated species, dogs were initially bred for their behavioral traits rather than their physical traits. These behavioral traits may have initially been tameness, with later skills such as tracking or herding being selected.

The region where these dogs were bred also played a role in the development of different dog breeds.

A good example of this is the herding trait.

Scientists hypothesized that all herding dogs would be closely related genetically because of the trait that had been bred for, regardless of where they were selectively bred. However, they found that was not true.

In different countries, they prioritized different strategies for herding flocks and had slightly different genetic pools to work with. By prioritizing different herding skills, the genetic makeup was found to differ from what was assumed.

Most of the dog breeds we see today can be traced back to Europe and the Victorian Era, 150 to 200 years ago.

The Darwinian Theory of natural selection highly influenced dog breeding during this period.

The process of selective or artificial breeding is similar to natural selection, except that, instead of the species breeding for survival, humans intervene to select traits they want in the animal. So, for dogs, if you want a specific coat color, you simply breed dogs with that coat color to try to make more of them.

The Victorian expansion in dog breeds specifically saw more dogs bred for appearance rather than behavioral traits. This led to drastic variation in body, skull, and limb proportions across species.

Dogs are descended from ancient wolves, and many of their distinct physical characteristics are linked to these ancestors. For example, traits like a dog’s height can be traced specifically to a more northern species of ancient wolf.

As dogs have been bred over the years, we have seen a distinction between “modern” and “ancient” breeds. “Ancient” dog breeds don’t mean the breed is extinct; instead, they were not developed during the Victorian Era.

Studies have shown that nine dog breeds can be distinguished from other European-origin breeds, and these breeds are considered the “Ancient” Breeds. These ancient breeds can be divided into three regions: Asian, Middle Eastern, and Northern.

The Asian dog breeds include the dingo, the New Guinea singing dog, the Chow Chow, the Akita Inu, and the Shar Pei. The Middle Eastern breeds are the Afghan hound and the Saluki. And finally, the Northern breeds include the Alaskan malamute and the Siberian Husky.

The classification of “ancient” breeds is hotly contested. Scientists argue over which dogs fit the terminology, if any dogs even fit the terminology, and if the word ancient should even be used. Regardless, the breeds I listed are almost always included, irrespective of the amount of genetic divergence.

Dogs can be considered “purebred” or “mixed breed.” The difference is simple: does the dog have parents, grandparents, great-grandparents, etc., of the same breed, or did two or more different types of dogs breed in the past?

A purebred dog is traced back through its ancestry by genetic analysis or written records. A dog is said to be purebred when both their parents are considered purebred and if it meets the “standards of the breed.”

The breed standards are detailed descriptions of each type of dog. These standards include observable behaviors and physical characteristics considered most important for the breed. If the dog does not exhibit these characteristics, it may be considered unacceptable or have faults.

Many purebred dogs face health issues and, on average, have a shorter lifespan. One of the best examples of this is in dog breeds with shorter noses, like the pug or bulldog. These dogs tend to struggle with breathing because they are selectively bred for short noses, which can lead to obstructed airways.

A crossbreed is a dog that is the result of two different breeds mating. Crossbreeding is done artificially, and the best example of this is designer dog breeds.

Designer dogs are a relatively new fad, emerging in the late 20th century. This trend was first seen when breeders crossed purebred poodles with other breeds. The poodle was chosen for its hypoallergenic coat. Later, other dogs were chosen to be crossbred to inherit the desired characteristics.

The puppies resulting from crossbreeding tended to take on traits of both breeds, such as the goldendoodle, or a golden retriever and poodle, the puggle, or a pug and beagle, and the Shepsky, or a husky and German shepherd, among others.

Crossbreeding can help eliminate some genetic problems but also carries its own health risks, though these are usually more apparent when two crossbreeds are bred together.

Mixed breeds or “mutts” are dogs that cannot be distinguished by one official breed, and are instead a mix of two or more. Dogs can be considered mutts even if they are the result of two purebred dogs, if they were not bred intentionally.

The term mixed-breed is somewhat misleading, as it suggests that dog breeds originated from a single source rather than being artificially created by humans.

There are also natural breeds of dogs that developed in isolation from humans. Many natural breeds tend to have longer lifespans than their artificially bred counterparts.

Another interesting aspect of dog breeding is their ability to interbreed with other wild members of the canine species. This is possible because all the animals are wolf-like subspecies that possess chromosomes, making them relatively indistinguishable from one another.

One example of this is the wolfdog.

Wolves are different from domestic dogs, with longer legs, slimmer chests, and stronger jaws. When wolves and dogs breed, the ratio of dog to wolf varies from individual to individual. Typically, wolfdogs have narrow chests, long legs, and sharper teeth than domesticated dogs due to their wolf heritage.

Interbreeding can also occur between domestic dogs and coyotes, and dingoes. Interbreeding between coyotes and dogs is rare due to their differing breeding cycles, but interbreeding between dingos and domestic dogs is very common.

Dingos have been mating with domestic dogs for years and have become so widespread that many dingos can be considered mixed-breed dogs. “Pure” wild dingos do exist in some areas, and can be considered a midpoint between wolves and dogs.

The legality of owning dog hybrids varies by area. In some areas, owning hybrids is completely illegal; in others, it is regulated; and in others, there are no laws.

There are many downsides to the selective breeding of dogs. The largest downside is the lack of genetic diversity.

Genetic diversity is important because it helps species survive. Having more traits means the species will be better equipped to adapt to different environments and to face diseases. Losing this diversity can increase a species vulnerability to these risks tenfold.

In dogs, this is most noticeable in purebred breeds, where it poses health risks. One of the best examples of this is with German shepherds. German shepherds have one of the lowest levels of genetic diversity of any dog breed, and this has led to numerous health problems in the breed.

German Shepherds were first bred in the late 1800s. The goal was to breed for herding and guarding traits to help protect sheep flocks. They were specifically bred for traits of intelligence and utility.

Today, the breed’s lack of genetic diversity has become a problem. Common disorders found within German Shepherds’ include elbow and hip dysplasia, and neurological disorders like degenerative myelopathy, which is a progressive weakness and lack of coordination in their back legs, which can become paralysis.

It is possible to protect purebred breeds from some of these health risks. The simplest solution is just to reduce inbreeding. By selecting mates with the least relation to each other, the two dogs will be less likely to share genetic conditions that could cause health problems.

Another tool is to increase the number of breeding dogs. Having more male and female dogs to breed with helps prevent future generations of the species from interbreeding, thereby maintaining genetic diversity.

The total number of dog breeds in the world depends on how you define “dog breed,” and what registry or authority you ask. Because of the ambiguity, there’s no single universally agreed-upon number.

That being said, the American Kennel Club currently recognizes 202 dog breeds.

Worldwide, some global or international registries estimate the total number of recognized dog breeds from major registries and clubs at roughly 400 to 500.

The amazing thing is that all of these dog breeds and the many crosses between them all originate from a single wolf species that got friendly with humans thousands of years ago.