What does Manuel do to Buck?

Manuel sells Buck to settle his gambling debts, which is a pivotal moment in the story. This act is significant as it marks the beginning of Buck's transformation from a domesticated pet to a creature that must learn to survive in the wild. The sale itself reflects the harsh realities of the world Buck finds himself in, where animals are commodified and their fates can change abruptly based on human actions. It sets off a chain of events that ultimately leads Buck to discover his primal instincts and true nature. Through this action, the themes of survival, civilization versus wilderness, and the impact of human greed are introduced, shaping the narrative of Buck's journey.