Domestic dogs belong to the same family as wolves, foxes, jackals and wild dogs. Their common name is Canidae. Real canines first appeared 5 million to 7 million years ago. It began to walk on four toes (the fifth toe gradually degenerated into a residual toe), and its toes were tight, which was very suitable for hunting.
Since Darwin's time, people have been arguing about the domestication of domestic dogs. Darwin was pessimistic about this problem. He believes that "the origin of most domestic animals may always be vague." The diversity of dogs is so obvious that Darwin tends to think that the ancestors of dogs are probably jackals, because the diversity of jackals is also very obvious.
No domestic animal is so exaggerated in appearance and temperament as a dog. Considering the huge difference between fierce Tibetan mastiffs and docile pugs, it is hard to believe that they are the same species. So that for a long time, people thought that dogs must have originated from several canines.
Extended data
Canine originated in the late Eocene. About 40 million years ago, they were the oldest group of carnivores, first differentiated from small ancient cats. There are three main lines in the evolution of canines, namely, three subfamilies of canines: modern canines, ancient canines and canine phobia (canines are similar to hyenas). ?
Archcaninae is an ancient branch of Canidae, which originated and developed in North America 40 million years ago. They look like a cross between a fox and a weasel. About 6.5438+0.5 million years ago, this branch gradually became extinct, and the genus Towne evolved into a canine phobia subfamily and survived. Canine phobia subfamily appeared 34 million years ago.
Like Archcaninae, they only exist in North America. Their size is much larger than that of ancient canines, and their appearance is between hyenas and dogs. Their big and powerful mouths are their characteristics. This species went extinct 2.5 million years ago.
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