Ambitious buck

I think natural selection, survival of the fittest and the law of survival of the fittest may be the most suitable for this work. Buck expressed not only his desire for survival, his fear of death, but also his love for life with his specific behavior, manner and language. If Buck lacked such a spirit from the beginning, how can we see it later?It is best for him to get rid of the wolf even in adversity and lead his companions on the right track expression.