Continuing with this concept of the survival of the fittest, Buck also soon learns that he can eat any type of food (even loathsome food) so long as doing so will help him survive. Furthermore, Buck's sight, his scent, and his hearing quickly develop a keenness which he never knew in civilized society. He is now even able to scent the wind, and he can tell what the weather will be like a night in advance. "And not only did he learn by experience, but instincts long dead had become alive again."
Carrying through with London's concept of naturalism (that maintains that there is a dimension of the primitive in all of us), Buck is beginning to remember back to ancient times before his own existence, to a time "when wild dogs ranged in packs through the primeval forest and killed their meat as they ran it down." Furthermore, on cold nights, Buck often points his nose toward the sky and howls like a wolf; "it was as though his ancestors . . . [were] pointing their noses at the stars and howling down the centuries and through him." This anticipates the final chapter of the novel when Buck will be seen roaming the forest with the wolf pack and will be seen answering the call of the wild by howling with the other wolves.
