In The Call of the Wild, the thirst to prove himself is a large part of Buck’s transformation into a more powerful and dominant dog. While pride does play second fiddle to survival, it explains why Buck excelled instead of merely staying alive. Pride is the difference between pulling the sled and being the lead dog on the sled team, between being adequately strong and moving a thousand-pound load. While pride does add complications to life in the wilderness (such as fights with other dogs for dominance), it is also beneficial a means of motivation.
Although at times it may have helped Buck grow and develop, pride is ultimately detrimental to the characters in the story.
While many changes to his character are necessary for Buck to adjust to the wild, it is his changing relationship with his own sense of pride that most defines Buck's growth.