Around the world, human beings growing interest in our best friends has resulted in an explosion of research about dogs. In fact in the last 10 years we’ve learnt more about dogs than was ever known in history, and this can be majorly attributed to a sudden excitement within the scientific community regarding our canine companions. But before this dog research frenzie set into action, one perplexing question had to be answered, in order to pave the way for the future canine science. This question was: How did dogs evolve to become so uniquely inclined to human sociality?
At first glance, this question does not seem to be extremely pressing, but the reason that scientists were keen on uncovering the origin of dog sociality was because they exhibited an understanding of human social cues (like pointing and gestures), that was not seen in our closest relatives, the chimpanzees and the bonobos. Furthermore, another puzzling detail to people interested in studying dogs, was how we could have q species sleeping in our beds, that was almost genetically identical to wolves. This is especially surprising when we consider the rocky relationship humans have had with wolves throughout history, where prehistorically they were our predatory competitors, and even recently are feared by most communities, and often killed as a result.
So given the historically rocky relationship between humans and wolves, and the fact that dogs have a unique affinity for human social cues, researchers began dwelling upon various hypotheses that could explain the origins of sociality in dogs. The 3 main hypotheses that researchers considered were the exposure, ancestry and domestication hypotheses.
The exposure hypothesis says that dogs develop the ability to read human social cues over the course of their lives, due to their constant interaction with human beings. This hypothesis explained how dogs exhibited a unique understanding of our social cues, because they are the species that are most frequently in contact with humans, more so than bonobos or chimps. However, this idea was rejected through tests on puppies. The social experiments conducted on 4 week old puppies with no prior human contact confirmed that dogs are born with the ability to understand human social cues, and that their ability to do so is not developed over the course of their lives.
Once the exposure hypothesis was ruled out, we turned to the ancestry hypothesis. Advocates of this hypothesis believe that dogs inherit their affinity for social cues from their ancestors, wolves. The rationale that justified this idea was that wolves are animals that live in hunt in packs, and thus their cooperative lifestyle must involve advanced social skills. However, when researchers conducted similar social games as the ones played with puppies in the exposure hypothesis, the results suggested that wolves do not pick up on social cues at all.
Thus, with the exposure and ancestry hypotheses ruled out, researchers turned to the final remaining explanation for the origins of dog sociality: the domestication hypothesis. This was the idea that as dogs evolved over time, their domestication allowed them to develop the ability to understand human social cues, (which means that they are born with it, and it is in their genes, rather than a result of their environment). This theory suggests that dogs evolved separately from wolves in a way that allowed them to read human sociality. The issue with this hypothesis was that unlike the other two, it seemed practically impossible to test it. This was because it required observing domestication, which is typically a gradual process that occurs over many generations. But this issue was resolved by the existence of the Belyaev Foxes in Siberia.
In a nutshell, the Belyaev Foxes are an artificial domestication experiment begun by biologist Dmitry Belyaev in the 1900s, where friendly foxes from each generation were interbred. Over time this generated two populations of foxes, a friendly experimental population and a randomly bred population. These foxes were key in confirming the domestication hypothesis because, when researchers tested them with social cue games, the friendly experimental foxes were able to read human sociality, whereas the randomly bred foxes were not able to do so. This finding was very convincing to scientists because even though the friendly foxes had never been previously exposed to human gestures, they were able to interpret them, where the randomly bred foxes were not, even after two weeks of human interaction.
In conclusion, the confirmation of the domestication hypothesis was a major breakthrough for studies in dog cognition and evolution, and ultimately has created the foundation for the future of research about our best friends.
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