Man is the expression of selective breeding dogs

Eyes stagnant, irresistible. How can we ignore this when our dog asks us something? In fact, we can’t, and now we know why. And this is one of the reasons why communication is so important. Wild animals – for example – communicate with each other through small mock movements that are difficult for us to comprehend. On the other hand, people have lost a lot of this kind of language by using words, they can say whatever they want without being forced to read. And he writes it less Conrad Lorenz In his famous book And the man met the dog.

Dogs and cats in the family: here’s how to communicate

By Irma D’Aria



The study, presented at the Experimental Biology (EB) 2022 meeting in Philadelphia on April 2-5, reveals that humans have contributed to the ability of dogs to produce dazzling faces for us through centuries of selective breeding. As already estimated by Everhard TrumlerA student of Lorenz, who was studying for his Masters at Neotini, said that people of the millennium would choose neotinic dogs, that is, puppies, with round, large spit and lazy eyes, because they stimulated tenderness and parental care.

I study

Ann BurrowsDogs, PhD, professor of physical therapy at the University of Pittsburgh’s Rangos School of Health Sciences and lead author of the study, say dogs are the only ones who can show their connection to humans through vision exchange. And the results of the study provide an in-depth understanding of the role of facial expressions in dog-human interaction and communication.

A story that began a long time ago, about 33,000 years ago, when there was supposed to be a difference between wolf and dog species, that is, when humans began to selectively breed wolves, thus becoming the first domesticated species.

The study is based on facial muscles or mimetics, a group of muscles just below the facial skin that are controlled by facial nerves. Their main job is to form facial expressions to express one’s feelings. In humans, these muscles contain a quick-twitch myosin fiber that shrinks quickly but wears out quickly, so we are able to quickly create facial expressions but not for long.

Man-made selection

By comparing myosin fibers to the oral muscle samples of wolves and domestic dogs, the researchers found that the oral muscles of both dogs and wolves are dominated by fast-twitch fibers, but wolves have a higher percentage of slow-twitch fibers than wolves. The latter interferes with longer and more controlled movements, which are chronic. When domesticated, humans can breed dogs based on their own facial expressions, and over time their muscles can become ‘faster’ and facilitate communication between dogs and humans.

All faults are fibrous

According to the study, the percentage of fast twitch fibers in dog samples ranged from 66 to 95 percent and in wolves an average of 25 percent. The average rate of slow twitch fiber in dogs is only 10% while that of wolves is 29% on average. Thus, in the distribution of myosin fiber, the physiology of the muscles of the dog’s mouth will be more similar to that of humans than that of wolves. Quick twisting fibers allow for greater mobility and smaller movements such as a raised eyebrow and small, strong muscle contractions associated with barking. Slow twitch fibers are important for increased muscle movement as wolves use when screaming.

In a previous study published in PNAS, the team found that dogs have an additional imitative muscle that is absent from wolves and contributes to “dog’s eye” expression. It is a muscle responsible for eyebrow lifting, a movement that promotes pedomorphosis, meaning preservation of childhood traits in adults (and let’s go back to Lorenz and Trumler’s neotini) and is often seen in people when they are sad. This kind of expression in dogs evokes tenderness and a desire for care. Presumably, dog eyebrows are the result of a selection based on people’s own preferences. Less normal, perhaps. But we like them that way too.

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