A person has five fingers and five fingers on his hands and feet, because exactly so many fingers were in the monkeys, from which all people descended. Monkeys, in turn, have so many toes from their ancestors — and so on, to the very first and ancient amphibians that lived on Earth more than 300 million years ago. It is believed that the common ancestor, a relative of all modern vertebrates that live on earth, had five fingers on the limbs. Since this has never bothered anyone at all times, but, on the contrary, helped to survive, evolution has preserved this feature for us and for other species.
This, of course, was not the case for all animals. For example, horses. Fingers would obviously interfere with them — so they «glued» and evolved into a hoof. Another version says that the hoof is only one thumb, and the rest were simply not needed. The man needed all this time all five fingers.
It must be said that a five-fingered limb does not have any fundamental design advantages compared to a four- or six-fingered one. Scientists believe that it was this number of fingers that formed as if by chance. There is such an ancient beast — ichthyostega — so she does have seven fingers on her hind legs.
In the most ancient terrestrial tetrapods, the number of toes also varied. It happened by chance that it was five fingers that gave rise to the whole variety of modern tetrapods, and animals with a different number of fingers died out. Of course, extinction did not happen at all because of the number of fingers, but for other, more significant reasons. With the same probability, animals with six or seven fingers on their paws could be lucky.
What would you do better if you had eight fingers and eight toes, huh?