While expounding the theory of evolution, he contacted the reality of China and warned people that they would die if they didn't cheer up. Yan Fu pointed out in his comments that there are many examples of survival competition, survival of the fittest and elimination of the fittest among animals and plants, and so are human beings. The victory or defeat of human competition lies not in the number of people, but in the strength. Facing the national crisis in China at that time, Yan Fu pointedly pointed out that China could no longer be conceited, ignore the reality and blindly play the old tune of "foreign". If you don't do it well, you will die. Evolution tells people the threat of national subjugation and extinction, but it is not negative and pessimistic. It enlightens people that although China is weak at present, there are still ways to save it, and that is strong competition. Through hard work, we can change the position of the weak and become the strong.