Buck shows no mercy toward Spitz in their final battle because he has fully embraced his primitive instincts after living as a sled dog in Alaska. The rivalry between Buck and Spitz was inevitable, fueled by mutual provocations and a struggle for leadership. Buck's transformation into a dominant beast culminates during the chase of a snow rabbit, where his bloodlust and survival instincts drive him to defeat Spitz, asserting his dominance over the pack.

Buck relies on his instincts in the wild by learning to avoid humans with clubs after being beaten, understanding the brutal law of "club and fang," and adapting survival strategies like burrowing in snow and eating quickly. He also steals food without moral qualms, fights fiercely against huskies, and defeats Spitz due to his instinctual leadership. Buck's instincts save him from dangers such as thin ice, highlighting his regression to primitive survival tactics in the Northland.

Buck's introduction to primitive law occurs when he witnesses a pack of dogs fighting, highlighting the natural hierarchy and survival instincts within the canine world. Initially a domesticated dog, Buck learns that strength and obedience are crucial for survival in the harsh Yukon environment. This introduction is reinforced by the man in the red shirt, who teaches Buck the importance of submission and obedience to humans as part of this primitive law.

Buck survives in the wild by reverting to his primal instincts, learning essential survival skills such as the law of club and fang, and becoming an adept hunter and food thief. He adapts by mimicking other sled dogs, learning to bury himself in snow and fight strategically. Experienced sled dogs already understand these survival rules, while domesticated dogs like Buck must quickly adapt or perish in the harsh Northland environment.

John Thornton is considered the "ideal master" because he treats Buck with genuine affection and respect, unlike Buck's previous exploitative owners. Thornton's relationship with Buck is characterized by mutual understanding and deep emotional connection, akin to Audre Lorde's concept of "sharing deeply any pursuit." Thornton's treatment of Buck as a beloved companion rather than an object for exploitation fosters a profound bond, highlighted by his instinctive care and Buck's love for him.

The narrator illustrates Buck's transformation by depicting his gradual shift towards primal instincts and ferocity, mirroring his wild ancestors. During a journey with John Thornton, Buck becomes drawn to the wilderness, responding to the "call of the wild" and befriending a timber wolf, which awakens ancestral memories. The death of Thornton severs Buck's last tie to civilization, prompting him to fully embrace his untamed nature through vivid visual, auditory, and kinesthetic imagery.

Buck's food-stealing is viewed positively because it signifies his adaptation to the harsh wilderness environment, where survival supersedes "civilized" values like property rights. In the wild, actions like theft are necessary for survival, contrasting with Buck's previous life in California, where his needs were easily met. Jack London emphasizes that in Alaska, survival requires earning and fighting for essentials, reflecting a shift in values from civilization to the natural world.

Buck is happy running with the wolf because he is increasingly drawn to his wild instincts and the "call of the wild," which stirs ancient memories within him. Despite this pull towards the wild, he leaves the wolf because his loyalty and love for John Thornton are still strong influences. Remembering Thornton, Buck chooses to return to the man who has shown him kindness and companionship.

Buck becomes increasingly prepared to heed the call of the wild as he transforms from a domesticated dog into a wild animal. Throughout the book, his survival experiences erode his civilized nature. By Chapter 7, following the death of his last human connection, John Thornton, Buck is entirely free from the ties to civilization and fully ready to embrace his new life as a leader of the wolves.

In "The Call of the Wild," patience is crucial for survival in the harsh Northland. It allows individuals to assess their environment carefully, avoiding fatal errors. London contrasts the fates of characters who lack patience, like Hal, Charles, and Mercedes, leading to their demise, with those who exhibit patience, like Buck. Buck's patience enables him to succeed in hunting and survival, highlighting its importance in the wild as a necessary trait for endurance and success.