Final answer:
Buck experiences an internal conflict throughout 'The Call of the Wild' but in the final chapter, it becomes external as he faces the wild environment and fully embraces his wild nature by becoming a wolf pack leader after losing his human ties.
Step-by-step explanation:
In The Call of the Wild by Jack London, Buck's conflict between civilization and the wild shifts from an internal struggle to an external one in the final chapter. Throughout the novel, Buck experiences an internal conflict where he grapples with his domestic, civilized past and the innate, ancestral call of the wild. This conflict manifests in his behavior and decisions as he adjusts to life in the harsh environment of the Yukon.
In the last chapter, Buck's conflict becomes external as he faces concrete challenges in the wild environment that stand in direct opposition to his survival. After the death of his beloved master John Thornton, Buck no longer has ties to the human world and is free to fully immerse himself in the wild. He encounters wolves and eventually becomes the leader of the pack, symbolizing his complete transformation and resolution of his internal conflict, having wholly embraced his wild nature.
The transformation highlights the larger thematic conflict between man and nature present in the novel, ultimately showcasing Buck's surrender to the natural world and abandonment of human constraints.