1) Biological pursuit of beauty is caused by sexual selection. In other words, only sexually reproducing creatures have the concept of "beauty" in Darwin's sense. The "beauty" or "ugliness" of an individual is a concept produced in the process of sexual selection. 2) In a certain creature, the opposite sex with good quality and health represents "beauty". Different creatures have different concepts of "beauty". For example, let orangutans vote and choose the most beautiful female orangutan from 10 thousand female orangutans, and the result will surprise mankind. . . On the contrary, our school flower is terrible in the eyes of orangutans. Different species have different definitions of "beauty" because the characteristics of the high-quality and healthy opposite sex are different in different species. 3) Darwinian beauty is mainly visual, but also olfactory and auditory. Girls' natural body fragrance and sweet voice are also beautiful. A healthy male toad barks loudly in the field, which is probably beautiful in the eyes of female toads. 4) Even the same species may have different definitions of beauty in different times, but the process of forming the concept of "beauty" is exactly the same, that is, the opposite sex characteristic that is conducive to reproduction is beauty. 5) Why do some shapes that obviously do not conform to the characteristics of biological reproduction remain and become a part of beauty? For example, the male peacock has beautiful feathers, but it makes it very inconvenient to move. Why did you stay? This is the result of sexual selection: healthy male peacocks grow beautiful tails, which female peacocks prefer. Although it is unfavorable to the survival of male peacocks on the whole, since they can grow such a long tail and survive to adulthood, they must have excellent genes. Knowing the above points, we can know the answer to this question, which is actually very simple: a beautiful face is a symbol of health. So how do people define a beautiful face? Symmetrical facial features, bright eyes, clean skin, white teeth, and so on. This is a sign of healthy development and good nutrition.