How is the man in the red sweater in the book call of the wild?

In "The Call of the Wild" by Jack London, the man in the red sweater is a brutal figure who represents the harsh realities of the dog-eat-dog world in which Buck, the protagonist, finds himself. He is a dog trader who uses a club to establish dominance and instill fear, teaching Buck the law of "club and fang." This character plays a crucial role in Buck's transformation, as he learns the importance of survival and adaptation in the wild. Ultimately, the man in the red sweater symbolizes the cruelty and violence of humanity that Buck must navigate in his journey.