How does Buck learn this law?

Buck learns the law of survival in the wild through a combination of harsh experiences and observations. As he faces the brutal realities of life in the Yukon, he witnesses the struggle for dominance among the dogs and the need to adapt quickly to survive. His interactions with other dogs and humans teach him the importance of strength, cunning, and instinct. Through these trials, Buck evolves from a domesticated pet into a resilient creature attuned to the primal laws of nature.