In The Call of the Wild the mention of Buck's forebears and his visions of ancient men by the fire is an example of?

In "The Call of the Wild," Buck's forebears and visions of ancient men by the fire exemplify the theme of primitivism and the connection to ancestral instincts. These elements highlight Buck's internal struggle between his domesticated life and the call of his wild heritage. They serve to illustrate his transformation as he reverts to his natural instincts and embraces a more primitive existence in the harsh wilderness. This connection to the past emphasizes the innate survival instincts that emerge as Buck adapts to his environment.