So, as it is told by Wolf Larsen in The Sea Wolf, the survival of the fittest does not only apply to man and beast, but to all of nature in general.

             Another method by which London tells us that only the strong will survive is through the many animals in his stories. In the novel, The Call of the Wild, an enormous dog named Buck is taken to the Klondike as a sled dog in the days of the Gold rush. Since Buck is a city dog, he must get accustomed to the ways and laws of the northern wilderness. London gives this description when he is telling the reader about the laws of the wild north: "The big eat the little that they may continue to move, the strong eat the weak so that they may retain their strength. The lucky eat the most and move the longest, that is all" (50). By using this law of nature, London depicts how the world of animals works and how it determines which ones live and which ones die. He is also saying that animals have to adapt themselves to different situations if they want to survive. London tells of this when he wrote, "Buck had a great capacity to adjust himself to changing conditions, the lack of which would have meant swift and terrible death" (53). In The Call of the Wild, London gave Buck the size, strength, and intelligence to conquer all other dogs and survive to live happily ever after. .

             The story of White Fang is also a novel involving animals where London shows his focus on the survival of strong creatures. In the story, White Fang is the main character. He is half wolf and half dog, however he doesn"t know whether he belongs in the wild or whether he needs a master to love him and take care of him. When he finally figures out that he wants to be a dog, he has great difficulty in being accepted by the other dogs in the village. His goal is to overcome the other dogs and prove to them that he is superior. As London put it, "He must master or be mastered; while to show mercy was a weakness.