This thesis is pided into four parts. The first part is about the analysis of different rules of survival of the fittest applied to Buck and White Fang in which survival of the fittest applied to Buck and survival of the fittest applied to White Fang are included. The second part is about the analysis of different owners of Buck and White Fang. The third part is about the discussion of different fates of Buck and White Fang; Buck eventually went back to nature, while White Fang adapted to civilization in the end. The fourth part talks about the causes of Buck and White Fang’s different destiny, which include the harsh cold weather, the way of adaption to life, the influence of human beings, the call of the wild, and the call of the kind. 《野性的呼唤》和《白牙》适者生存的对比分析(3):http://www.youerw.com/yingyu/lunwen_12255.html