First of all, there are many kinds of dogs, and their size, color and curly hair are very different. For this reason. At first, people thought that they evolved from different wild canines. Therefore, in 1758, dogs are listed as an independent breed.

Secondly, the conclusion that the ancestors of dogs are wolves is that with the deepening of research and the progress of science and technology. With the help of genetic technology, biologists have found that grey wolves are closely related to dogs. Until now, they can still reproduce together.

Finally, although some breeds of dogs are similar to wolves, dogs have been completely domesticated by human beings. Its body structure and body language are also very different from those of wolves. By measuring their skulls, the researchers found that the corners of the eyes of most dogs were wider than those of wolves. The wolf's tail is vertically downward, and the dog's tail is rolled up. Tail is the weakness of animals, and it is the most easily overlooked position when they are in danger.