The secret that makes dogs look cute lies in their 'changing facial expressions', and dogs make facial expressions with 'quick muscles' that are rarely found in wolves.

If you've ever owned a dog, you've probably seen it change its face like a human, with a fluttering face when it's happy and a shun when it's sad. Experts point out that the facial expressions that dogs show to humans, especially the muscles that make up the facial expressions around the eyes and mouth, have completely different characteristics from the dog's ancestors, the wolf.

Experimental Biology 2022
https://www.eventscribe.net/2022/EB2022/fsPopup.asp?PresentationID=1027886

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At Experimental Biology 2022 , an academic research presentation event held in April 2022, research results on the muscles that make dogs' facial expressions were presented by a research team of Anne Burrows and others at Duquesne University in the United States. .. In another study they published earlier, they found that there are muscles around the dog's eyes that wolves don't have, and that dogs capture the human mind with the 'puppy-like eyes' realized by these muscles. I have made it clear.

Dogs have evolved to acquire 'puppy-like eyes' that move human hearts --GIGAZINE

Burroughs and colleagues, who continued to study dog facial expressions, focused on the structure of the muscles on the dog's face and took samples of muscle cells around the eyes and around the mouth and compared them to wolves.

The results show that 66-95% of dog muscle fibers are composed of fast-moving but easily fatigued 'fast muscles', while wolf 'fast muscles' are only 25%. .. On the other hand, the percentage of 'slow muscles' that are slow but have endurance is only 10% for dogs, while it is 29% for wolves. This means that dogs have more developed muscles to quickly change shape around the eyes and mouth than wolves.

The following is a sample of stained facial muscles arranged in the order of wolf, dog, and human from the left. The muscles of a dog's face are more like humans than wolves.

'This difference suggests that having more agile muscle fibers has a positive effect on dog-human communication,' said Burroughs. In the process of domestication, humans may have selected and bred dogs that look similar to themselves, which makes the dog's muscles faster and easier to communicate with humans. Isn't it? '