People have wondered about the origin of dogs for as long as people have been breeding dogs (which is a very long time indeed!). Geneticists and archeologists now agree that ancestor to modern dogs separated from other wolves over 20,000 years ago, and that by 15,000 years ago, they were fully dog-like and spreading around the world.
How (and why) did these “proto-dogs” evolve into dogs? Like many Mesolithic human cultures, wolves are cooperative hunters using diverse strategies (like persistence hunting) to bring down large game animals like elk and buffalo. Gray wolves and human hunters were crossing paths in Eurasia for tens of thousands of years, and human-wolf bonding events like the one depicted in the feature film Alpha, almost certainly occurred countless times. Wolves recognize human individuals and show affection towards caregivers, so although wild wolves generally avoid humans, they do have some social flexibility under the right circumstances.
To make a dog, you need a wild population of wolves to adapt to people. Wolf populations are certainly adaptable—coastal wolves are quite different than their Arctic brethren. They are also opportunistic, not only as hunters but also as scavengers. If a mobile band of humans successfully killed a mammoth, a wolf would certainly like to grab a bite if it could get away with it.
Being a successful scavenger is a bit different than being a successful hunter. Persistence and intelligence are still required, but instead of reading the cues of the prey to determine when to strike, you need to read the cues of the people around the prey. Wolves that could tolerate people and determine who was friendly and who was a threat were the most successful scavengers. Successful scavenging also doesn’t require a large body size; and smaller sized proto-dogs were probably even more successful as scavengers (more tolerated by humans). Freed of the demands of hunting, these smaller sized proto-dogs could reach reproductive maturity faster and out-reproduce their feral cousins.
Because these genetic changes for tameness and smaller stature improved scavenging efficiency at a cost of hunting efficiency, proto-dogs were locked into their new evolutionary course. With around a billion dogs in the world today (and only about a million wolves), it’s been a very successful strategy! As our companions, dogs evolved (like people) in response to the new diets of the Neolithic, and like people have spread out to inhabit nearly every habitable corner of the world. Dogs have also been intentionally bred into hundreds of diverse breeds enabling them to perform diverse roles, including guarding, sledging, tracking, and racing. They made certain ways of life possible, and almost certainly assisted in the domestication and management of other species and the spread of humans to certain remote regions. It is impossible today to imagine the trajectory of humans progress if we didn’t have dogs by our side.
Check out the Alpha Movie trailer!