This first theft marked Buck as fit to survive in the hostile Northland environment. It marked his adaptability, his capacity to adjust himself to changing conditions, the lack of which would have meant swift and terrible death.

Buck’s first theft—he steals food—is symbolic since it signals that he has what it takes to survive in any environment. London’s novella plays out many of Darwin’s theories and ideas of the survival of the fittest, which emphasize adaptability as a key trait to survival of a species over the ages. Buck not only adapts but adapts quickly. Buck goes from “sated aristocrat” to ruthless survivalist in a matter of days, outwitting and outfighting his competitors, slowly proving his mastery.

He wanted, not to escape a clubbing, but to have the leadership. It was his by right. He had earned it, and he would not be content with less.

The narrator explains that Buck realizes early on that he not only wants to survive, he wants to rule, which sets him apart from the other dogs. Spitz wants to rule but lacks leadership skills. Dave doesn’t want to rule; he seems content being a stalwart friend and guide and dies a tragic and heroic death. Buck, however, feels a deeper drive in him to live up to his true potential, a potential great in size. Buck possesses both mind and might, the key traits of mastery.

He had killed man, the noblest game of all, and he had killed in the face of the law of club and fang.

When Buck discovers John Thornton’s body, he flies into a rage. Spotting the perpetrators, a band of Yeehat natives, he springs into action, seizing the throat of one and killing him instantly. This event, as described by the narrator, serves as a crucial moment as all of Buck’s trials over the novella culminate in this one elegant though brutal act. Buck proves that he has the skills and power to kill a species “higher” in rank than him. In this moment, Buck shows that he has regained the primal mastery of his wolf ancestry.

Like a flash, Buck struck, breaking the neck. Then he stood, without movement, as before, the stricken wolf rolling in agony behind him.

Here, the narrator describes the scene toward the end of the story when Buck faces his last enemy: a pack of wolves. Buck stands in a clearing, a huge figure looming over the pack. The wolves charge, and Buck attacks in a flash, killing one instantly. Buck battled his way to leadership of the sled dogs, and here he is battling his way to the leadership of the wolf pack. Buck’s fight for mastery appears at its greatest pitch here, as he tries to reclaim a position of leadership among the most primitive versions of himself.

They are afraid of this Ghost Dog, for it has cunning greater than they, stealing from their camps in fierce winters, robbing their traps, slaying their dogs, and defying their bravest hunters.

In the last chapter, London describes how the Yeehat Indians refer to Buck as “Ghost Dog” for his devastating, stealthy attacks on their camps. The Yeehat don’t see ever see Buck, but they know his power. Buck has conquered weak civilized men, consummate outdoorsmen, and human masters of the wild. Through his innate skills, will to power, and successful trials, Buck has mastered both the civilized and primitive environments and achieved his destiny as a master hunter, survivalist, and primal beast.