Scientists' research results from molecular dating show that the history of human domestication of dogs began 33,000 years ago. "Domestication has changed the facial muscle anatomy of dogs and is specially used for communicating with human faces." Julian kaminsky and Bridget M Waller, who participated in the new study, said that the dog's eyebrow expression is the result of human preference. "This is an amazing difference for species that were isolated only about 33,000 years ago."
A large number of behavioral data of domestic dogs and wolves show that domestic dogs produce "eyebrow movement" with higher frequency and greater intensity. The movement between the eyebrows makes the dog's eyes look bigger and makes the face more like a baby, similar to the expression produced when human beings are sad. The possible evolutionary scenario is that human beings intentionally or unintentionally prefer to produce this kind of movement, which may arouse human caring response and make individuals who inherit this feature become human preference objects.
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Taboo: Don't touch a strange dog's ass and tail. The dog's code of conduct for strangers is to judge the strength of his opponent according to the height of his sight. When a stranger approaches, the oppressive feeling of coming down from above will make him uneasy. If you keep a low profile, he will accept you. For a strange dog, squat down and look away. Taboo: don't look at strange dogs, so as not to cause provocative misunderstanding to dogs.
A dog shows its belly to others as a sign of surrender, repentance, obedience and coquetry. Dogs never attack opponents who fall and show their bellies. Sleeping with his stomach up shows that he is at ease or trusting, so that people can see or touch his stomach.
When a dog and a dog meet for the first time, a lower-ranking dog will show his belly when he sees a higher-ranking dog, even if the other person is full of anger. The human smile and the wagging of the dog's tail are similar forms of communication. Dogs use their tails to hint at psychological reactions, which is a kind of "language".
Generally, when you are excited or happy, you will shake your head and wag your tail. The tail not only swings from side to side, but also keeps spinning. The tail is tilted up to show joy; A drooping tail means danger; The tail does not move, indicating anxiety: the tail is tilted, indicating fear; Shake your tail quickly and horizontally, symbolizing friendliness. The movement of the dog's tail is also related to the owner's tone.
When a dog is sick, it will instinctively avoid humans or other dogs and hide in the dark to recuperate or die. This is an "atavism".
The ancestors of dogs lived in groups. If any dog in the group is sick or injured, other dogs will kill the injured dog to avoid suffering after being dragged down or left behind. This should attract the attention of dog owners or breeders and should be treated by veterinarians in time. Use urine to mark "territory, attract the opposite sex, or be a road sign".
Dogs evolved from wolves also inherited this habit from their ancestors. Dogs have territorial habits and occupy a certain range to protect themselves from other animals. They use anal gland secretion to make feces have a special smell, sweat secreted by sweat glands between toes and pictures of scratching on the ground with hind legs as territorial markers. Dogs like to chase creatures, and people use this characteristic of dogs to drive away cattle and sheep and protect themselves.
References:
Xinhuanet-After 33,000 years, dogs have such a "long" expression.
Baidu encyclopedia-dog