What are the dreams Buck has of a man squatting by a fire in the darkness in Call of the Wild?

In The Call of the Wild by author
Jack London, Buck dreams of a man squatting by a fire as the dog dozes by the
fire.

The dreams represent Buck’s break from his civilized
life at the judge’s house and entry into the wild. He has killed his antagonist, Spitz,
in a bloody one-on-one battle, and risen to the top of canine ranks. As Buck dreams
before the fire, he is beginning to heed the call of the wild. He sees a prehistoric
man, ape-like in description, uttering strange sounds around his own fire. Buck is
reconnecting with his primordial being and forgetting his life of comfort where
civilized rules applied.

At the time London wrote the
novel, the world was stunned by news of Charles Darwin’s theory of evolution. Buck’s
transformation illustrates a connection between the dog’s new life in the wilderness and
his ancestors’ lives with hairy men around the fire. It is quite similar to the world
Buck inhabits after he was kidnapped and sold during the gold
rush.

At
other times this hairy man squatted by the fire with head between his legs and slept. On
such occasions his elbows were on his knees, his hands clasped above his head as though
to shed rain by the hairy arms. And beyond that fire, in the circling darkness, Buck
could see many gleaming coals, two by two, always two by two, which he knew to be the
eyes of great beasts of prey. And he could hear the crashing of their bodies through the
undergrowth, and the noises they made in the
night.

Buck has severed his
ties with civilization and is on his way to ruling the
wilderness.