The phrase “Man’s best friend” is a common phrase popularized by the poet Ogden Nash, and has become a familiar saying when referring to dogs. Unquestionable in their greatness, the domestic dog exhibits a close relationship with humans, showing loyalty, companionship and unconditional love.
The domesticated dog (Canis familiaris) is a direct descendent of the grey wolf (Canis lupus), but over thousands of years, dogs have evolved not only in their behaviour, but also in their appearance – developing shorter teeth, shorter muzzles, and let’s face it – enhanced cuteness levels. But why did this evolution take place, and how did dogs make the journey from feared predator to lovable pup?
This journey is not fully understood and there are many controversies surrounding the separate theories – some of which (and the reasons they are not 100% accepted) are as such:
- When humans arrived in Europe 43,000 years ago most large predators were wiped out, why weren’t wolves?
- Humans used wolves to hunt and they formed a working relationship, for example leaving some meat for wolves – but humans were successful hunters without wolves – and wolves eat a lot of meat.
- Humans have a long history of eradicating wolves – almost all cultures in the last few centuries have hunted wolves to extinction.
Some scientists believe that it was wolves that first approached humans – possibly when scavenging around the garbage dumps of human settlements – bold aggressive wolves would have not been tolerated and would have been killed – but friendly wolves per se could have been tolerated and therefore selected for.
Selecting for the friendlier wolves caused strange things to happen within them, thus triggering domestication, and these wolf-dogs (for want of a better description) quickly became cuter, fluffier and got waggier tails. But not only this, these wolf-dogs developed the ability to read human gestures and speech.
As a culture that is now used to having domesticated dogs, the ability of dogs to be able to read human gestures is taken for granted, and the fact that this is a truly remarkable ability is lost. Dogs can read our facial expressions, certain words and the intonation of human speech. Even our own closest relatives – bonobos and other primates such as chimpanzees are not as good at reading our gestures as dogs do. In this way, dogs have evolved to become eerily similar to our own children, and this accounts for the extraordinary relationship we have today with our dogs.
Due to this ability, these friendly wolf-dogs were worth knowing to our ancestors, and people who had dogs during a hunt would likely have an advantage over those who did not. Even today, tribes in the Congo and Middle America depend on dogs to hunt. Moose hunters in the alpine regions have been observed to bring home 50% more prey when they are accompanied by dogs.
Wolf-dogs could have also served as an early warning system to their human counterparts – barking at hostile strangers from other tribes, and potentially defending their humans from predators, thus earning them a place at our fire.
I will leave you with this quote from Voltaire – “DOG – it seems that nature has given the dog to man for his defence and for his pleasure. Of all the animals it is the most faithful: is the best friend man can have” (1764).
This is part one of a series of blog posts on the evolution and domestication on dogs by Dr Matthew Yates. Matt gained his PhD in 2014 studying the role of macrophage migration in neuropathic pain and atherosclerosis. His interests lie in psychobiology, haematology and dogs. He is currently working in a clinical haematology field.