You speak dog much better than you think. You can't speak it fluently because that would require being a dog. But if you lived in a dog world, you would understand what they are saying. You can tell a nervous yip from a threatening growl, a bark that means hello from a bark that tells you to leave him alone. You can read body language that says he is happy, sad, tired, or even scared, begging you, or asking you to play with him right now!

You think it doesn't mean anything specific? Then tell me... what does a happy bird look like? A sad lion? You don't know? But you do when it comes to dogs, and even more so when that dog is yours. And just like your human mother tongue, you didn't have to force yourself to learn it. You grew up in a world where dogs are everywhere, and you just got it.

This reveals a lot about the bond between humans and dogs. We live with cats, we work with horses, we rent cows for their milk and chickens for their eggs – unless we kill and eat them as needed.

With dogs, things are different. Our world and their world swirled together like two shades of paint long ago. Once you get orange, you never go back to red and yellow.

But why? It is not enough to claim that the relationship is symbiotic, that dogs hunt for us and consider us their herd while we keep them warm and fed in return. Sharks and remora fish have a similar agreement: the remoras remove parasites from the shark's skin and are entitled in return to the remains of the shark's dead fish. This underwater agreement is entirely transactional; love plays no role. Humans and dogs, on the other hand, adore each other.

The relationship began a long time ago – well, no one knows exactly when it began. The oldest remains of humans and dogs buried together date back 14,000 years, but some unconfirmed finds are thought to be twice as old. The most important point is the significance of the findings: we lived with dogs and then chose to be buried with them. Imagine that.

Our ancestors didn’t know what genes were millennia ago, but they did know that every now and then a medium-sized scavenger or two with a long muzzle would come poking around their campfires, looking at them with a certain attention, a certain need for love, and that it was terribly difficult for them to resist. So they took them in to shelter them from the cold and began to call them dogs, while some of their close relatives who didn’t have this “good gene”—the ones we would eventually call wolves, jackals, coyotes, or dingoes—would be left to fend for themselves in the wilds where they were born.

When humans themselves left the wild, our alliance with dogs might well have been dissolved. If you didn’t need a working dog—and more and more people didn’t—then there was an imbalance. We continued to pay the dogs their wages in food and shelter, but we received little tangible in return. Never mind! By then, we were already infatuated.

Our language reflected how much we were in love: the word “puppy” is said to have been adapted from the French word “doll” – an object on which we lavish irrational affection. Our folk stories were populated with dogs: Africans spoke of Rukuba, the dog who gave us fire; the Welsh told the story of the faithful dog Gelert, who saved a prince’s baby from a wolf. Aristocrats began to include the family dog ​​in family portraits. Wealthy eccentrics began to include dogs in their wills.

Today, at least in areas populated by humans, the dog is the most abundant terrestrial carnivore on the planet. There are about 900 million of them worldwide. The single species, the domestic dog – Canis lupus familiaris – has been subdivided into hundreds of breeds, selected for their size, temperament, color or finesse.

The average dog owner spends over $2,000 a year on food, toys, medical care, and more, and some people would be willing to pay much more. When Hurricane Katrina hit New Orleans in 2005, so many people refused to evacuate without their dogs that Congress passed a law requiring disaster preparedness plans to accommodate pets.

What began as a contract of mutual service between two very different species has become something much more like love. It makes no sense, but it doesn’t have to. Love rarely touches the parts of the brain responsible for reasoning. It touches the dreaming parts, the devoted parts—it touches the parts we sometimes call the heart. For thousands of years, that’s where our dogs have lived, and for many more, that’s where they will continue to live!