Thousands of years ago, men and canids began to walk together and benefit from their friendship relationship. The domestication of dogs has been a very complex process and there is considerable debate in the scientific community in terms of dates and key moments in this story, but the truth is that the best friend of the man has some very unique characteristics that they have helped him to adapt to his pet status.
Now, a curious study just published in the journal PNAS suggests that dogs developed specific muscles around the eyes whose sole function is to better communicate with humans. Thanks to them, dogs can make that characteristic gesture of raising an eyebrow when looking at us, which, according to the authors, would trigger a response in humans similar to that which originates when we look at a baby, since their eyes seem larger and sad and inspire us with feelings of protection and tenderness.
The study, led by a team from the University of Portsmouth (USA), consisted of a comparative analysis of the anatomy of wolves and dogs , suggesting that the latter had developed very specific facial characteristics that would allow them to better communicate with humans. In addition, the team also compared the behavior of dogs and wolves: “When we exposed them to the presence of a human being for two minutes, the dogs raised their eyebrows more and with greater intensity than the wolves,” explains Juliane Kaminski, lead author of the job.
Furthermore, in previous studies, the team of scientists had also observed that dogs move their eyebrows more when someone is looking at them. “This movement is very significant in the human-dog bond because it could provoke a protective response and, on the other hand, it could also create the illusion of a human-type communication, ” says the expert.
Evolutionary meaning
How do you get to this point? According to the theory of natural selection, during the domestication process of dogs, those with more expressive facial expressions would have provoked in their owners a stronger desire to protect them , so they would have survived – and reproduced – more, reinforcing this trait in future generations.
The surprising thing is that this feature has taken hold in record time. The results reveal, as we have seen, that the brow raising movement is driven by a muscle that does not consistently exist in its closest living relative, the wolf. ” This is a surprising difference if we think that we are talking about species that separated only 33,000 years ago “, explains Anne Burrows, professor of anatomy at Duquesne University, (Pittsburgh, USA) and co-author of the work. Such rapid facial muscle changes may be directly related to the social interaction of dogs with humans, “adds the expert.
“Our findings show how important faces can be to capture our attention, and how powerful facial expression can be in social interaction,” says Bridget Waller, another of the authors participating in the work.
Of all the dogs analyzed, the only one that did not have the muscle studied was the Siberian husky, which is precisely among the oldest breeds and therefore closest to the wolf.
The study of the evolution of muscles is quite complex, since soft tissues do not persist in fossil tissue, so that only elucubrations can be made from the comparison between current species and races. However, this research sheds a little more light and helps us understand some of the mechanisms that underlie dog domestication over the years.
