Answer:
The dog eat dog world of the Klondike awakens within Buck a "dominant primordial beast” that drives him to "master, or be mastered.” Buck chooses "to master” by overthrowing Spitz and asserting his rightful place as lead dog on François and Perrault's team. Domination is Buck's aim and he achieves it. Mastery, however, is not just a relentless struggle for power and dominance. London describes Buck's pursuit "to master” as a learning process. Buck "masters,” or comes to dominate his fellow dogs by learning, or mastering, survival skills. He "receives instruction” from the other sled dogs about how to work in the traces and learns "lessons,” like burying himself in the snow to keep warm, or deferring to man's authority when that man wields a heavy club.
The pursuit of mastery is not just limited to the canine world; it's active in the human one, as well. Buck's human owners parallel Buck's drive to dominate through their attempts to tame the wild, both animals and nature, alike. Buck's various owners exert mastery over canines by exchanging these animals like commodities, disciplining them and charting their course across the Klondike. Meanwhile, miners, such as John Thornton, carve through the earth so that they can harvest gold, while pioneers such as Hal, Charles, and Mercedes try to settle the Klondike by imposing their worldly possessions upon it.
Man's will "to master” nature stifles Buck's own innate drive to dominate. While Buck masters other dogs, man masters him. Buck is not able to fully assert his mastery until he flagrantly defies the law of club and fang by attacking the Yeehats. In doing so, Buck willfully overturns man's dominance over dog, but also gains autonomy. Free from man's mastery, he is able to roam nature freely as the leader of a wild wolf pack. Buck has not only mastered the ways of the wild, but his own fate.
Explanation:
https://www.litcharts.com/lit/the-call-of-the-wild/themes/the-pursuit-of-mastery#:~:text=Buck's%20human%20owners%20parallel%20Buck's,their%20course%20across%20the%20Klondike.
sparknotes.com/lit/call/quotes/theme/mastery/
Hope this helps.