Humans and dogs have been co-existing for at least 15 000 years although fossil remains of canines and humans have been found at prehistoric sites that could date as far back as 36 000 years ago.
The dog was the first domesticated species. Modern domestic dogs evolved, along different paths, from Asian and Eurasian grey wolves. The time and location of domestication remain under debate.
Wolves chose us
It seems that it was the ancestors of our dogs that chose to live with humans in mutually beneficial relationships and not the other way around.
The theory is that the boldest of wolves scavenged leftovers discarded by early humans on the edges of settlements. Over generations, their offspring became bolder still and moved closer to the people they came to rely on for warmth and companionship as well.
Over time, humans realized that the animals were natural allies and began breeding them to be better hunters and herders.
90 percent of dogs are descended from 3 female wolves.
It is thought that individual animals with the gentlest temperament, the intelligence to learn human social cues, the ability and willingness to help with human hunts and provide protection for their human companions, were encouraged to remain with the tribe.
But wolves with the ability to adapt to living with humans were very rare. Genetic testing has shown that 90 percent of the domestic dogs living today have descended from only three early female wolves.
Man’s best friend and the love hormone
Humans and dogs have become hardwired over the millennia for the unique relationship they share.
Scientists have found that dogs and their owners experience surges in the hormone oxytocin, which is associated with bonding and affection, when they look into each other’s eyes. A rush of this hormone could help to explain the relationship between humans and dogs as animals experience it as well.
Oxytocin spikes in the female brain when she looks into her offspring’s eyes and strengthens the bond between them. This process regulates the female drive to care for and protect her offspring.
Do dogs have empathy?
Simply petting a dog can decrease levels of stress hormones, regulate breathing and lower blood pressure. Research has also shown that petting releases oxytocin in both the dog and the human.
Psychologist Debbie Custance of Goldsmiths College, University of London says: “Dogs are social creatures that respond to us quite sensitively and they seem to respond to our emotions.”
Custance led a study to see whether dogs demonstrated empathy. She asked volunteers to either pretend to cry, or just “hum in a weird way”.
“The response was extraordinary,” she said. Nearly all of the dogs came over to nuzzle or lick the crying person, whether it was the owner or a stranger, while they paid little attention when people were merely humming.
To some people, the idea of sending a dog to a grieving person might seem too simplistic. But Custance says that the very simplicity is part of what makes the connection between humans and canines so powerful.
“When humans show us affection, it’s quite a complicated thing that involves expectations and judgments,” she said. “But with a dog, it’s a very uncomplicated, nonchallenging interaction with no consequences. And if you’ve been through a hard time, it’s lovely to have that.”
WATCH: Domesticating the dog