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When looking at a dachshund and a Great Dane, it's hard to believe that these dogs trace back to the same ancestors. Yet it's 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 exact same species. Learn more about the development of dog breeds and why there are so many on this episode of Everything Everywhere Daily.

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This episode is sponsored by Aura Frames. If you're looking for a gift for someone close to you, I highly Recommend Checking out auraframes. With auraframes, you can set it up in about 2 minutes and share memories all year long. You can upload directly from the Aura app on your smartphone and share your images more securely than email or social media. It can also display short videos up to 30 seconds long with audio. Aura Frames have meticulously calibrated high resolution displays. Unless you look really closely or see a photo transition, you'd never even know it was a screen. I have an auraframe in my house and I love it as it's a great and simple way for me to display the many thousands of photos I've taken on my travels. For a limited time, save on the perfect gift by visiting auraframes.com to get $35 off Aura's best selling Carver mat frames, named one by Wirecutter by using promo code daily at checkout. That's auraframes.com promo code daily. The deal is exclusive to podcast listeners and frames sell out fast, so order yours now to get it in time for the holidays. Support the show by mentioning it at checkout. Terms and conditions apply. This episode is sponsored by the Tourist Office of Spain. If you've been listening to this podcast long enough, you might think you know Spain well. Think again. There is so much more to Spain than what most people think. In fact, every part of Spain is packed with history and culture. Extremadura in the west is home to fantastic Moorish architecture and Hamanabirico, the world's greatest pork product. In the north, Galicia Asturias and the Basque country have stunning coastlines, amazing food and unique cultures. The island of Lanzarote in the Canary Islands has a volcanic landscape and the Tabernacle Desert has been a filming location for many Western films. The city of Merida has some of the greatest Roman ruins you'll find, and in Valencia, the home of Paella, you can even find the Holy Grail. Plan your next trip and learn about all the lesser known gems in spain@spain.info Once again, that's spain.info.

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To understand the creation of dog breeds, we 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. But for the sake of this episode, I'll provide a short summary. Dogs hold the distinction of being the first species humans ever domesticated and the only large carnivorous mammals to undergo this process. All dogs are descended from an ancient wolf population, and they're considered to be the same species classified under the scientific name Canis lupus familiaris. That means that every domesticated dog, regardless of size, shape, or color, are all 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, and that means a Chihuahua and a Great Dane can technically interbreed with each other, although in that particular case there could be some logistical issues. Scientists debate the timing of dog domestication, but most research dates it to around 12,500 to 15,000 years ago, although there are some researchers that 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 1 people domesticated dogs to help with hunting 2 wolves scavenged at human waste sites, making them more accustomed to people or three 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, they 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 just 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 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 that we see in the world today can be traced back to Europe in the Victorian era, about 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 that of natural selection, except that instead of the species breeding for survival, humans intervene to select traits they want in an animal. So for dogs, if you want a specific coat color, you simply breed dogs with that coat color and try to make more of them. The Victorian expansion in dog breeds specifically saw more dogs bred for appearance than for behavioral traits. This led to drastic variation in body, skull and limb proportions across species. As dogs are descended from ancient wolves, 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 that the breed is extinct. Instead, they were just not developed during the Victorian era. Studies have shown that nine dog breeds can be distinguished from other European origin breeds and that these breeds are considered the ancient breeds. These ancient breeds can be divided into three 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 ancient breeds include the Alaskan Malamute and the Siberian Husky. The classification of ancient breeds is actually hotly contested. Scientists argue over which dogs fit the terminology, if any dogs should even fit into the terminology, and if the word ancient should be used. Regardless of that, the breeds that I listed are almost always included in any listing of ancient breeds, irrespective of the amount of genetic divergence within the breed. Dogs can be considered purebred or mixed breeds. 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 with when both its 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 the 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 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 tend to take on traits of both breeds, such as the goldendoodle or a golden retriever poodlecross, the puggle, a pug and a beagle, or the Sherpski, a husky and a German shepherd, among others. Crossbreeding can help eliminate some genetic problems, but it 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're the result of two purebred dogs if they were not bred intentionally. The term mixed breed is also somewhat misleading as it suggests that dog breeds originated from some single source rather than being artificially created by humans themselves. 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 the ability to interbreed with other wild members of the canine species. This is possible because all the animals are fundamentally wolf like subspecies that possess chromosomes, making them relatively indistinguishable from each other. One example of this is the wolf dog. Wolves are slightly 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, wolf dogs 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 domestic dogs is rare due to their different breeding cycles, but interbreeding between dingoes and domestic dogs is actually rather common. Dingoes have been mating with domestic dogs for years and have become so widespread that many dingoes can be considered mixed breed dogs. Pure wild dingoes 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's regulated, and in others there are no laws whatsoever. There are many downsides to the selective breeding of dogs. The largest downside being 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 notable in pure breeds where it poses health problems. 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. German Shepherds were first bred in the late 1800s. The goal was to breed for herding and guarding traits and 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 the back legs, which can lead to 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 just 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 that you ask. Based on the ambiguity, there's no single universally agreed upon number. That being said, the American Kennel Club currently recognizes 202 breeds of dog worldwide. Some global or international registries estimate the total number of recognized dog breeds from major registries and clubs at roughly 4 to 500. And the amazing thing is that all of these dog breeds and many of the crosses between them all originate from a single wolf species that got friendly with humans thousands of years ago.