Dogs were not created by inbreeding– but they are being destroyed by it

Image from Cappella dei magi in Florence. Work by Benozzo Gozzoli.

A common misconception that continually gets spread is that domestic dogs were created through inbreeding wolves and that the different specialized breeds and types were created through inbreeding.

There is almost no evidence for either assertion.

The first assertion is easily falsified. Domestic dogs retained most of the wolf’s genetic diversity through domestication– in the neighborhood of 95 percent.  Wolves are a very genetically diverse species, so dogs, as a population, really do have a lot of genetic diversity for a domestic animal.

Further, there is no evidence that these specialized dogs were created through inbreeding.

Retrievers, for example, were always celebrated as being crossbred dogs. That’s right. For most of their history, different dog breeds were bred together to create retrievers of various types. It’s just the retrievers that derived mostly from the St. John’s water dogs that became the most celebrated and “improved” into modern breeds. Prior to modern breed formation, retrievers were bred through crosses in this fashion. Many retrievers had collie, St. John’s and Large Newfoundland, setter, and land and water spaniel ancestry, and others even had terrier and greyhound in them.

All they selected for was for dogs that would carry things in their mouths. And you can get that from a wide variety of dogs.

Now, retrievers are modern working dogs. Their exact function really didn’t become widely necessary until shotguns were invented. Before that, dogs like poodles and barbets were used for this purpose– and they were were often employed to retrieve shot arrows that missed their marks.

Earlier dog types were created, but they were created as landraces.  One of the oldest landraces is the tazi family of sighthounds. These dogs were among the earliest specialized dogs to have formed from the wolf. They are a very diverse lot. Some are shaggy. Some are smooth. Some are merely feathered.  But they are pretty genetically diverse as a landrace, and they are found from North Africa across the Middle East to China. In Asia, they are found from Siberia to India.

Because these dogs are pretty diverse, we know that they likely weren’t created by inbreeding. In fact, some regional variants have mtDNA squences that they share with local pariah dogs. The azawakh has mtDNA sequences that are similar to African village dogs, while Israeli salukis sometimes have mtDNA sequences in common with the Canaan dog.

So as this type evolved from the wolf, it likely incorporated genes from less specialized dogs. That’s not a closed registry system at all.

However, these dogs were selectively bred from genetically diverse stock over a long period of time.

This is very similar to the domestication process that Mark Derr describes in How the Dog Became the Dog.  Over tens of thousands of years, wolves and people began to affiliate with each other. This happened over a broad swathe of Eurasia. Over time, these wolves began to evolve into dogs.  During the last glacial maximum, Derr contends that the first phenotypically distinct domestic dogs appeared, largely because they were suffering from lack of prey for both humans and their socialized wolves to hunt. These dog features were not created through intense inbreeding, though the eventual development of the small dogs at the end of the Pleistocene may have been maintained by inbreeding.

At their founding, dogs were, by and large, genetically diverse.

This diversity was maintained in two ways.

Prior to the development of pastoralism, wolves were largely tolerated near human camps. Wild wolves and dogs exchanged genes quite a bit.

And humans were movers. In the days of the hunter-gatherers, dogs would always be on the move. If dogs are moving all the time, so are their genes. So there would always been a gene flow across Eurasia– and this would prevent any one population of dogs from becoming inbred.

Now, this is the exact opposite of what some people think. They think all of these dog breeds developed in complete isolation, and they regularly inbred to keep things going.

Actually, that wasn’t true even after the rise of agriculture around 10,000 years ago.

Once agriculture got started, people could remain in one place all the time, so it could be possible that people would start to become isolated– and their dogs would become inbred.

However, there were two aspects that always prevented this from happening.

One of these is trade. Trade has been a big thing even before humans began living in agricultural settlements. The earliest evidence of long-distance trade dates to as early as 150,000 years ago, and when settlement allowed people to produce more advanced goods, they were very interested in spreading it as far as possible.

Dogs had to have gone along with these early trading forays, leading to a continued gene flow.

Further, although most agriculturalists were sedentary, pastoralists never were.

Pastoralists were always following herds and flocks up and down mountains to access the best grazing, and in other areas, they moved their stock to better watering places from areas experiencing drought or dry seasons.

Everyone knows that dogs were and still are a vital asset to any pastoralist. They can alert the pastoralist to predators, and if the dogs are big enough, they can even kill them. They also can run off rustlers and bandits, and they can be used to manage the flocks and track down strays.

But because pastoralists are always moving, so are their dogs. And as their dogs move, they spread their genes.

One of the very good parts of Raymond Coppinger’s book is that he recognizes how important this movement of humans across these routes every year is very important to the story of the domestic dog. This movement is called “Transhumance,” and it has likely had a major role in maintaining genetic diversity in domestic dogs than we might have realized. Dogs traveling with pastoralists from village to village were mating with dogs belonging to villagers, and in this way, local genetic diversity was maintained.

The thing that actually created all the inbreeding in domestic dogs is the development of modern breeds.

Modern breeds that exist within a defined closed registry system are very new. They have only appeared in the past two hundred years– most in the last 150.

In this system, there was a delusion that one could continually improve upon the types and landraces by separating them from other dog stocks and then tightly breeding upon these dogs to set type. This exact same method was tried on cattle, sheep, and horses– and then fancy show pigeons. Results were quite substantial in those species, which were now much more productive, and the pigeons became more and more esoterically bizarre– the exact result the early pigeon fancy wanted!

In the early days, there were successes.

But over time, this sort of very close breeding and breeding within closed registry systems have had a deleterious effect upon domestic dogs.  Dogs within these breeds have lost 30 percent of their genetic diversity over the past two centuries.

Genetic diseases are encountered much more commonly in dog breeds than in almost all other organisms, though the notorious inbred factory farm turkeys are definitely more diseased in this fashion.

Many dog breeders exist under the delusion that they can breed out all the diseases their breed possesses. Many of these diseases are simple recessives, so all you’d have to do is inbreed to expose the disease and then cull. That works to a point.

But usually what happens is they select out a disease is they often wind up doubling down on something else.

Not all diseases are simple recessives either.  In fact, it has yet to be proven to me that the majority of them are.  Many are the result of several genes which are inherited in different ways, and it is very hard to selectively breed them out of a population.

The other problem is that the MHC haplotypes within any inbred population are very easily lost or become very homozygous rapidly. You cannot see MHC haplotypes, but if you breed them out and the dogs have more and more homozygous haplotypes, you will have a compromised immune system on your hands.

So you might breed out the easily defined genetic diseases, and in the end, you’ll wind up with dogs that are infertile or dying of autoimmune diseases– neither of which is uncommon in many dog breeds.

For tens of thousands of years, people have bred from genetically diverse dogs.

Now we’re seeing the full consequences of squandering genetic diversity in the name of delusion.

Diversity is the solution to so many problems in domestic dogs.

Unfortunately, the very notion of diversity conflicts with the long held shibboleths and bromides that underpin the dog fancy that has developed in the past two centuries.

Delusion is dangerous because it is more than a lie. It is a lie that the liar himself doesn’t know is untrue.

And to fight off the pesky truth, the deluded grabs at straws to excuse his delusions and make them true.

This, folks, is about 80 percent of what is written about dogs in the modern era.

Excusing and dismissing facts to hold onto delusion.