There are many theories as to the way in which dogs first joined humans and began the process of domestication. Over time as science has improved, our knowledge of DNA and Epigenetics has increased, and our ability to trace genetic mutations in the DNA of fossils has increased, it has become more accepted that one theory (Population Selection) is more likely to explain how today’s domestic dog evolved into it’s own unique species apart from its wild ancestors.
15,000 years ago, at the end of the last ice age, humans began to settle in one place for the first time and establish small communities. Where there are groups of people, there is waste – both human and food waste. Intelligent, brave wolves with a strong instinct to survive would have discovered that it was very beneficial for them to hang out around the outskirts of these small human villages as there was a never-ending supply of food. Wolves with a larger flight distance (meaning that they would not be as comfortable being as close to humans as other of their species), would not have chosen to hang around in the same way as their braver counterparts. Over time, the wolves with the lower flight distance would have become more and more habituated to being in the presence of humans while eating and so would have been happy to stay in closer proximity to them. Raymond Coppinger says that domesticated or ‘tame’ really could mean ‘being able to eat in the presence of humans’ and believes that this was the start of the domestication process of dogs. Natural selection weeded out the weaker wolves (weaker in the sense that they lacked the bravery to remain close to humans despite there being a readily available food source) and allowed for the stronger to remain together in a small community.
It is possible that a bit of the founder effect came into play at this point. Wolves who exhibited the ability to habituate to the presence of humans would have broken off from their old packs and in a sense created a new community of wolves who lived around, and scavenged the perimeter, of human settlements. These wolves all would have carried genes that resulted in a smaller flight distance and so with mating over generations this would have become more prevalent in their population. Relaxed selection would have taken over as food was abundant and breeding attempts would have been more successful. The population of ‘friendlier’ wolves would have increased as a result.
The genome is the entire genetic make-up of an individual, and this is received equally from both parents. As populations of ‘friendlier’ wolves broke away and formed their own small groups, breeding among themselves would have increased the likelihood that offspring would also carry genes that would result in this behaviour and comfort around humans. The epigenome is a cluster of chemicals that affects how a gene behaves. It is effectively an on and off switch in the body that can either amplify or suppress a gene depending on what is going on in the environment of the species. Wolves that figured out the benefits to living near humans likely benefitted from a bit of epigenetics and had their bravery increased because it improved their chances for survival. Co-evolution of humans and dogs may have started to occur rand humans realized that they could use these ‘friendly wolves’ to enhance their own lives by using them for work. As dogs and humans developed a closer relationship, physical changes appeared in dogs over time, including splotchy coats, curly tails, and floppy ears. This follows a pattern of a process known as self-domestication. It’s what happens when the friendliest animals of a species somehow gain an advantage. Friendliness somehow drives these physical changes, which can begin to appear as visible by-products of this selection in only a few generations.
Today’s 350+ breeds of dogs have largely come about due to artificial selection by humans. Wanting dogs who could help in many areas of their own lives (such as hunting, shepherding, guarding, work and company) humans selected for (and continue to select for) physical or temperamental traits, health conditions, skills and aptitudes that they believe would give them the best results in the area they were looking at and bred dogs with the best of those traits (also known as artificial selection). For example, Russel terriers were bred to be fast, tough and compact, with a strong instinct to hunt prey underground so that they could participate in fox hunting. Dogs who displayed these characteristics would be bred together in the hopes that their offspring would have similar traits. Dogs with larger bodies who move slowly would not be helpful to people who needed help hunting very quick animals, and so breeding dogs to perform specific roles began. Long before the kennel clubs existed, humans were breeding hunting dogs for speed, good reflexes, explosivity and a lean body, herding dogs for stamina, endurance and long distance training, and bullfighting dogs for their strong jaws, flatter face, low centre of gravity and bulkier build. While artificial selection may have initially served humans well in that they were able to carry out tasks relating to their own survival with the help of dogs a bit more easily, as time has gone on, this breeding process has resulted in many ‘designer dog breeds’ being created strictly for looks and convenience, as well as a number of breeds who experience debilitating health issues (short snouted pugs and bulldogs, or ‘brachycephalic’ breeds).
Although modern day dogs and wolves share a common ancestor, today’s domesticated dogs have a very different gene pool as a result of artificial selection and are now entirely unique to their wild ancestors.
If you are interested in learning more about modern day wolves in Europe, how they live and which behaviours of modern day dogs are still typically 'wolf', check out the FREE "Wolf Awareness Workshop" at the link below:
Canine Principles: Canine Coaching Diploma Online Coursebook
“The Genius of Dogs: Discovering the Unique Intelligence of Man’s Best Friend” by Brian Hare, Vanessa Woods, Oneworld Publications (Feb, 2014)
"Dog Emotion and Cognition" Online Course: Dr. Brian Hare, Duke University (2019)
What Caused the Domestication of Wolves? (Oct 2011): https://www.pbs.org/wnet/nature/dogs-that-changed-the-world-what-caused-the-domestication-of-wolves/1276/