What is the primary theme of "The Call of the Wild"?

The primary theme of "The Call of the Wild" centers around survival of the fittest and the instinctual pull towards nature, which is vividly illustrated through the protagonist, Buck. This theme encapsulates Buck's transformation from a domesticated pet into a feral creature that embraces his natural instincts. As he faces various challenges in the wilderness, the story highlights the idea that the wild is an unforgiving place where only the strongest survive. Buck's journey is a powerful exploration of his innate instincts, showcasing how he adapts and ultimately reverts to his ancestral traits in order to thrive in his harsh environment. This theme resonates throughout the narrative, underscoring the concept of natural selection and the inherent drive all creatures have to connect with their primal selves.