How did dogs develop into pets?
Dogs were one of the oldest animals to be domesticated, where they likely were domesticated by at least 15,000 years ago. This shows they have played an important role in the history of human societies. While dogs became domesticated relatively early in complex human societies, their history as pets is generally less clear.
Early Use of Dogs
Dogs were most likely domesticated in the Middle East, Central Asia, or even China. While it is well known that dogs originated from wolves, as they are still able to mate, indicating their close genetic affiliation, it is not clear which type of wolf may have led to their domestication. One idea is that the Siberian, Eurasian wolf, or Middle East grey wolf or their relatives, although not necessarily a direct ancestor of modern wolves, may have been the first wolf to be domesticated into dogs. In any case, there may have been multiple regions spanning Eurasia where domestication occurred. This suggests that their utility different in the various regions in which dogs were domesticated. The initial use of dogs varied as guard animals or even as a food supply. The fact that they were likely domesticated before agriculture became present in most places also suggests their role in hunting may have been important. In fact, some of the oldest known breeds, such as the Basenji, appear to be related to hunting and possibly guarding, suggesting that most early domestication of dogs favored this specific role.
While wolves are known as hunters, the reality is they also spend a lot of time scavenging. It is this scavenging behavior that likely brought them close to human encampments. This would suggest that human populations likely noticed a potential symbiotic relationship, where wolf-like dogs could eventually provide protection and help in hunting. Initially, wolves would have been likely seen as a threat, but studies have shown that wolves can be relatively quickly tamed. Within on generation, a wolf born can be more tame and within a few generations wolves can begin to loose their wolf-like qualities (e.g., pointy ears) and begin to be tightly integrated into human societies and even within placed within the house.
Dogs as Pets
As wolves-dogs were increasingly utilized for hunting and protection near human camps or eventually settlements, their utility expanded even more with the onset of agriculture. By then, protecting crops and domesticated animals (e.g., sheep and goats) from other humans and animals became an import function. Given that speed, ability to quickly identify threats, and be able to fight back were desirable traits for protection, this made dogs ideal for roles in agricultural societies. However, if dogs were only aggressive, this would mean they could be a threat to the inhabitants of settlements. Thus, what likely occurred is that dogs were trained to identify those they are linked with, through their day-to-day contact, and those who have little connection to them. This made dogs, as they evolved, become better able to differentiate different people and threats. While in the encampment or settlement, the evolving dogs had to be trained for more docile actions. This likely made them more friendly and easier to control. In fact, in nature, wolves have been found to be among the most gregarious animals and they show a high degree of cooperative traits compared to many animals (e.g., their ability to hunt together in packs requires cooperative behavior). These traits likely helped them develop into more friendly breeds, while still retaining characteristics for protection and hunting.
By historical periods, over 5000 years ago, dogs begin to be shown as more pet-like animals. In ancient Mesopotamia, the goddess Innana was shown as having seven dogs accompanying her. Dogs were also discussed in various ancient mythology in Mesopotamia, where they served as companions and provided a protective guard.