As we all know, long ago, human beings evolved from animals. The habits of humans and animals in primitive times don't have much errands. At that time, human beings can be described as slovenly. Everyone has a lot of hair, and there were no clothes like this in primitive times. ? So we can only cover our bodies with the fur of some animals. At this time, human hair plays an important role, while nails only play a role in tearing food at that time. With the retirement of time, humans began to walk upright and create things. With the evolution of nature, human hair and nails gradually degenerate, only some places are covered with hair, and human nails are also very short. Nails and hair exist only for beauty. Scientists have found that hair has a regular growth cycle, and tests have found that the hair cycle lasts for 2? Six years, leg hair can only grow for half a year, and animal hair also grows periodically.
After climate change, the nails and hair of most animals will naturally fall off and then grow again, so the nails and hair of animals have been growing, but they don't need to be repaired all their lives. Some scientists believe that this result is caused by the difference of keratin content in hair. The keratin content in human hair is different from that in animals. Chimpanzees are closest to us, but there are still differences in keratin content. Animals' nails are related to their living habits. In primitive times, animals used claws to catch prey, and nails were also indispensable at this time.
How do animals catch prey when they cut their nails in the wild? Humans eat with chopsticks, forks and other tools without nails. People's nails don't have much effect, but they are more beautiful. Nails gradually degenerate in the process of human evolution, but animal nails are sharp weapons.