The roles of three characters are essential to the understanding of the theme of this story. Because the theme of this story is the survival of the fittest. This theme show about how to survive when they fall in a difficult situation. Such as The three characters know how to fight to survive in the north. Because they have the weapons to hunt and protect themselves.
they know how to drive, and how to treat the team. Although two of them don't know how to treat the dogs. And they are lack of understanding about animals