How does Buck's relationship with Spitz evolve during their rivalry?

Buck's relationship with Spitz evolves into an increasingly hostile rivalry as the story progresses. This dynamic is rooted in their competition for dominance within the sled dog team. Initially, Buck respects Spitz as the lead dog, but as Buck grows stronger and more confident, he begins to challenge Spitz's authority, which leads to tension between them. Their rivalry intensifies as they engage in constant power struggles, ultimately culminating in a fight for leadership. Buck's determination to assert himself and become the top dog drives the hostility, representing his transformation and adaptation to the harsh realities of life in the wild. The culmination of their rivalry reflects Buck's inner journey and evolution as he embraces his primal instincts, making this hostility a vital aspect of the narrative.