When were dogs invented

Have you heard the latest news? We’ve decoded the DNA of dogs. Here’s how the media-approved version of the story goes: We’re showing our love for “man’s best friend” by discovering and treating the genetic causes of his ailments. In return, we’ll learn to treat the same ailments in ourselves.

It’s a heartwarming story, but it’s a fraud. The reason we targeted the dog genome for decoding is that it’s useful for genetic research. The reason it’s useful for genetic research is that dogs are neatly divided into breeds, each of which is plagued by specific diseases. And the reason dogs are divided into diseased breeds is that we made them that way. Dogs are the world’s longest self-serving, ecologically reckless genetic experiment, perpetrated by the world’s first genetically engineering species: us.

Dogs were just a loose category of wolves until around 15,000 years ago, when our ancestors tamed and began to manage them. We fed them, bred them, and spread them from continent to continent. While other wolf descendants died out, dogs grew into a new species. We invented the dog.

We didn’t pick just any wolves for this project. We picked the ones that could help us and get along with us. Dogs are dumber than monkeys and other mammals in many ways, but they excel at one thing: interpreting human behavior. Three years ago, scientists tested this talent in wolves, adult dogs, puppies raised in households, and puppies raised in kennels. The wolves couldn’t read humans well, but the puppies could—even the puppies raised in kennels. Through selection, we’ve hardwired human compatibility into dogs. We’ve made a species in our image.

But that wasn’t enough. We had specific needs. We bred hunting dogs, herding dogs, sled dogs, and guard dogs. (We also tried a few unauthorized uses.) We turned reproductive separation and inbreeding into a science, multiplying and dividing the species into more than 400 breeds. The American Kennel Club sorts them into the Sporting Group, Working Group, Herding Group, Hound Group (whose ancestors were “used for hunting“), Terrier Group (whose ancestors “were bred to hunt and kill vermin“), and Toy Group. “The diminutive size and winsome expressions of Toy dogs illustrate the main function of this Group: to embody sheer delight,” says the club’s Web site. Every dog has his duty.

Each need, each breed, called for special traits. We bred collies for vigilance, Rottweilers for aggression, retrievers for obedience. In a span of decades, we bred ferocity into Dobermans and then, with equal deliberateness, bred it out. We treated dogs like guns. We designed and bought them for protection, then complained when they hurt us. When cities banned pit bulls, we bought Rottweilers. It was as easy as replacing an illegal assault weapon with a legal one.

Not all our designs were utilitarian. We made some breeds just for fun. Some, like the Pharaoh Hound, were thought to be ancient because they looked like dogs drawn on Egyptian tombs. But last year, when we checked their DNA, we found no evidence they were older than modern breeds. Apparently, breeders crafted them by mating dogs that looked like the drawings. Life imitated art.

In the course of engineering dogs to look, feel, and act as we wanted, we ruined millions of them. We gave them legs so short they couldn’t run, noses so flat they couldn’t breathe, tempers so hostile they couldn’t function in society. Even our best intentions backfired. Nature invented sexual reproduction to diversify gene pools and dilute bad variants. By forcing dogs into incest (which we ban among humans, in part for biological reasons), we defied nature. We concentrated each bad gene in a breed, magnifying its damage: epilepsy for springer spaniels, diabetes for Samoyeds, bone cancer for Rottweilers. That’s why the dog genome is so nifty: We can find disease genes just by comparing one breed’s DNA to another’s.

Well, too bad for the dogs. But three cheers for us and our experiment. “The dog genome is a wonderful playground for geneticists,” exults the New York Times. “A treasure trove,”  says  the San Francisco Chronicle. “A convenient laboratory,” agrees Reuters.

Man’s best friend, indeed.

By Michael Marshall

Today’s dog breeds are descended from wolves

Christian Müller/Alamy

Dogs may have become domesticated because our ancestors had more meat than they could eat. During the ice age, hunter-gatherers may have shared any surplus with wolves, which became their pets.

The timing and causes of the domestication of dogs are both uncertain. Genetic evidence suggests that dogs split from their wolf ancestors between 27,000 and 40,000 years ago. The oldest known dog burial is from 14,200 years ago, suggesting dogs were firmly installed as pets by then.

But it isn’t clear whether domestication happened in Europe or Asia – or in multiple locations – or why it happened. Dogs are the only animals domesticated by hunter-gatherers: all the others were domesticated after farming became widespread. One suggestion is that people domesticated dogs to help them with hunting, while another scenario has wolves scavenging human waste dumps and becoming accustomed to people.

Maria Lahtinen of the Finnish Food Authority in Helsinki and her colleagues suggest that the key may have been a surfeit of meat.

Read more: We’ve seen wolf pups play fetch just like dogs for the first time

Dogs were domesticated when ice sheets covered much of northern Eurasia and the climate was colder than today. During this time, humans and wolves would have competed for food, as both are top predators.

However, wolves can survive on nothing but lean meat – which contains protein and little else – for months. In contrast, humans cannot. There are limits to how much protein our bodies can handle, so we have to eat other food groups such as fat as well. “We are not fully adapted to eat meat,” says Lahtinen.

Her team calculated how much food was available during the Arctic winters, based on the prey species living there. They found there was an excess of lean meat, suggesting human hunters would have ended up with more of this than they could consume. Wolves could have eaten this surplus, implying the two species weren’t in competition during the harsh winters. Instead, humans could have shared lean meat with wolves without losing out themselves.

Lahtinen suggests that hunter-gatherers may have taken in orphaned wolf pups – perhaps viewing them a bit like pets – and fed them on spare lean meat. They probably didn’t have any long-term goal in mind, but the tamed wolves would have later proved to be useful hunting partners – reinforcing the domestication. “They must have been very attractive for hunter-gatherers to keep,” says Lahtinen.

Journal reference: Scientific Reports, DOI: 10.1038/s41598-020-78214-4

A look back at how our furry four-legged family members became our friends.