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It has been said that a dog is a man’s best friend.
This might be true, but…..why. How was it that this particular animal developed such a special relationship with humans?
How did the domestication process take place, and where did it happen?
…and how is it that there are so many different breeds of dogs that call came from the same original source?
Learn more about the domestication of dogs and how it happened on this episode of Everything Everywhere Daily.
The story of humans and dogs goes back to before the dawn of civilization when our ancestors were hunters and gatherers. Dogs were the very first animal ever domesticated by humans. They were domesticated long before horses, cattle, sheep, or cats.
Whenever we go back that far, details become sketchy because we have no written or even oral records.
It was the onset of DNA analysis that gave us our first real glimpse of when dogs were first domesticated and where they probably came from.
The domesticated dog has the scientific name Canis lupus familiaris. One of the most shocking things about domestic dogs that not everyone knows is that all domestic dogs are the same species.
As radically different as dog breeds are, they are all fundamentally the same thing. A 120-pound Irish wolfhound is the same species as a 5-pound Chihuahua. This is seen in the fact that different breeds of dogs can interbreed with each other.
One of the definitions of a species, although it can be a bit fuzzy around the edges, is the ability to breed with other members of the same species.
Birds might look as different from one another as dogs do, but birds don’t interbreed.
The closeting living wild relatives of domestic dogs are grey wolves or timber wolves. Today they can be found in North America and northern Eurasia.
The point when dogs genetically split off from wolves occurred about 20,000 to 40,000 years ago. This was around the last glacial maximum. This period doesn’t represent the point where dogs were domesticated, however. That occurred later.
Everything I just described, we are able to know via genetic evidence. It might be vague, but it is pretty solid.
Where there is a great deal of debate is how, when, and where dogs were domesticated. There are several theories on the domestication of dogs, and most of them suffer from the same dearth of evidence.
The ‘when’ is one of the least contentious things. The domestication is generally believed to have occurred around 15,000 to 11,500 years ago.
That 11,500-year point is one that has come up before in many episodes, as it was truly a turning point in the history of the earth and the human race. It was the end of a period known as the Younger Dryas, but I will leave that for another episode.
Where the domestication took place is where there is the real debate.
One camp holds that dogs were domesticated somewhere in East Asia around 12,500 to 11,500 years ago.
The other theory holds that the domestication event took place in Europe around 15,000 years ago.
These two theories are not necessarily mutually exclusive with each other. If there were two independent domestication events, then the Asian variant probably migrated west and supplanted the European domesticated dog.
There is yet another theory that dogs were domesticated in Central Asia and spread both east and west simultaneously.
Finally, a study published in 2021 claims that dogs may have been domesticated in Siberia as far back as 20,000 years ago. If this is true, it might explain how domesticated dogs made it to both Europe and the Americas during the last ice age.
The earliest evidence we have of dogs and humans living together was found in Europe. There was a grave site found in Bonn-Oberkassel, Germany, that dates back 14,000 years.
In China, a grave with a domesticated dog was found that dates back about 8,000-9,000 years ago.
The earliest evidence of dogs in the Americas comes from a grave found in Utah, which dates back about 11,000 years ago.
These dates of dog and human burials put a lower bound on when we can be certain domestication occurred, but we have no idea what that upper bound is, which is why there is so much uncertainty.
One problem with excavating remains in Southern China, for example, is that a hot wet climate isn’t good for the preservation of fossils.
The next big question is how and why dogs were domesticated.
Here we can only speculate, but the standard story goes something like this….
Early humans were out hunting, processing their kill, or perhaps they were sitting around a fire eating the rewards from that day’s hunt.
Some wolves, which, for whatever reason, had no fear of humans, would sneak up and try to take some of the leftovers and scraps.
Over time, humans became comfortable with these wolves, and the wolves found this to be a winning strategy. Hanging out with humans was easier than being low on the totem pole in a wolf pack. They fed you, you could stay new a warm fire, and in return, you just had to help warn the humans of danger and maybe help them drive animals during a hunt.
The key here is that this was a trait that the dogs had. As they bred, usually with other docile dogs that were hanging out with humans, this trait would have eventually been passed down. Dogs would eventually be born and grow up amongst humans.
An interesting side note, while domesticated dogs are related to wolves, they have been interbreeding for thousands of years. Remember when I said that one definition of a species is if the animals can interbreed? Well, I also said that the lines can sometimes be fuzzy, and this is such a case.
You could argue that wolves and dogs are still the same species for this reason, although they are very different.
Anyway, one of the odd things about the grey wolf is that not all of them are grey. Occasionally there are black wolves and sometimes white wolves. Geneticists believe this mutation might have come from domestic dogs bred with wild wolf populations.
There are more of these non-grey wolves in North America than there are in Eurasia, indicating that domestic dog-wolf interbreeding might have occurred more frequently.
Another interesting thing about the ancient remains of dogs that have been found with humans is that the size of the skeletons varies considerably. Very small dog remains have been found as well as very large dog remains. This would seem to be early evidence of dog breeds.
However, there is a DNA test that is run used to genetically distinguish dog breeds called SNP or single-nucleotide polymorphism. Using this test, the different size dog remains do not seem to be different genetic breeds.
One of the biggest changes to humans was also a huge change for dogs. The creation of agriculture.
Humans became sedentary, and this changed dogs as well.
Dogs were naturally selecting their own traits to live with humans. This was replaced with humans purposely breeding the traits that they wanted. This included size, docility, and intelligence.
Dogs began to be trained to perform particular functions, such as herding sheep, goats, and cattle. Dogs also managed to provide protection against wild animals who might otherwise try to eat animals and crops that were grown by farmers.
Dogs also were assigned the task of killing rodents on many farms, even though this was a service that was later assigned to domesticated cats, but that is another episode.
In the Americas, dogs were the only domesticated animal in many civilizations.
Dogs were the only pack animals available north of the Andes, where they had llamas. Dogs would pull what was known as a travois, which was just two sticks that dragged on the ground. Dogs were the primary method of moving goods and supplies, when native people had to migrate from one camp to another.
Most dogs were still not kept as pets as we think of them today. They were working animals in a world where almost everyone lived on farms.
In fact, it is estimated that today, ¾ of all domestic dogs worldwide do not live with any specific humans but rather live communally amongst humans. I have seen this all over the world where dogs who don’t seem to have any obvious owner will just run around the streets of a city.
One of the first international destinations I ever traveled to was Argentina, and I remember seeing homes with elevated metal baskets outside their homes. I had no idea why they did this, and eventually, someone told me it was so the dogs wouldn’t get into their garbage.
Up to about the middle ages, the domesticated dogs that existed would certainly be recognized as dogs, but what you didn’t see was the wide variety of breeds that exist today. Everything was probably what we would define as a mutt, with some exceptions for highly specialized dogs, such as water dogs.
In fact, almost all breeds of dogs can only be dated back about 500 years, and the majority breeds, less than 150 years.
Certain categories of dog breeds such as toy dogs would have served no real function
In particular, the 19th century saw massive growth in selective breeding for particular phenotypes. As dogs can reach sexual maturity within a year, it is possible to rapidly develop breeds with certain traits if it is the intent of the breeder.
The World Canine Organization, which is an international association of national kennel clubs, recognizes 360 different dog breeds.
There are still new dog breeds being registered. In just the last few years, the American Kennel Club has recognized the Barbet, a very hairy dog from France, the Azawakh, a hunting dog from West Africa, and the Dogo Argentino, a muscular hunting dog from Argentina.
So, while dogs and humans have had a long relationship with each other, the question still remains, why dogs? Why were dogs the first animal to be domesticated and not something like a lion or even a horse?
There are several attributes which wolves had which made them rather natural candidates to cozy up to humans.
For starters, wolves are naturally social animals. Wolves usually live in a pack and are custom to interacting with other animals.
This ability naturally lent itself to socialization with humans. Other animals like lions tend to be more solitary.
Second, wolves are predators. Animals that are prey tend to be much more skittish and run away from anything which approaches them. A predator would be much more likely to approach another animal or show curiosity.
Finally, wolves were the right size. An animal like a lion would have probably scared even a good-sized group of humans if it approached them. A solitary wolf, however, isn’t as much of a threat. Even a small group of humans could take on a wolf, especially if they have spears.
Anything smaller than a wolf probably wouldn’t be noticed.
I’ll end with a very interesting experiment that was conducted in Russia to determine just how fast it would take to create domesticated dogs.
Russian scientist Dmitri Belyaev began an experiment in the early 1950s where he was to try to breed a domesticated fox from an initial population of wild silver foxes. I should note that there was no such thing as a domesticated fox before this experiment started.
For 50 years the experiment ran, and each generation was selectively bred on how little fear they had of humans.
By the early 2000s, they had a population of foxes that basically showed no fear of humans at all. They would lick the hands of humans, wag their tails, and exhibit many of the same behavioral signs that domesticated dogs do. This isn’t to say they are a totally domesticated animals yet, but their behavior has changed radically compared to their ancestors 50 years earlier.
The behavior wasn’t the most interesting thing. They also started to show changes physically. They had tails that were more curly, their ears were more droopy, and their coats began to develop spots. All of these are traits often found in domesticated animals across the board.
It is believed that there might be a collection of genes that work together and if you breed for behavior, you will also get these physical changes.
Wherever and whenever dogs were originally domesticated, what is undeniable is that dogs and humans have grown together and that humanity’s four-legged friends have played a role, however small, in the world we have today.
Everything Everywhere Daily is an Airwave Media Podcast.
The Executive Producer is Charles Daniel.
The associate producers are Thor Thomsen and Peter Bennett.
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