what forces ,natural and human ,shape white fang's character and how do they affect him?

The novel portrays two worlds, the world of nature and the world of humans. In both these worlds, all life is subject to the law of the survival of the fittest. Famine is well known to both humans and animals, and when it comes, the weak, the sick, and the old die. When the Indians have no food to give the dogs, the dogs return to the wild and try to stay alive until the famine passes. If they succeed, and if they find their old masters again, they often return to human society. But when hardship comes, it is every man, woman, child, dog, wolf, and pup for himself or herself. Relationships are based on mutual benefit, not on affection.

In the last section of the novel, White Fang enters a kind of paradise where the law of survival of the fittest has been superseded by the law of love. Weeden Scott rescues him at the moment when the law says he should die, and from that moment on White Fang lives in a radically different kind of world. The world of love, however, is one that most creatures never experience and one that White Fang reaches only after much extreme suffering—only because a kind man happens to come along at just the right moment, only because he was born with enough intelligence to be rehabilitated, and, above all, only because he has been tough enough to survive until that moment.