In Chapter IX of James Michener's historical novel, Alaska, gold is discovered in Nome and two of the characters based upon real people, move to this territory in hopes of making their fortunes. Once there, they encounter gold mine thieving, dangerous conditions, and dangerous men. In the setting of this novel and London's novella, Alaska is a raw, naturalistic, formidable land that is unforgiving of any weakness.
This portrayal is, indeed, realistic. With so many men journeying to Alaska in hopes of making a fortune, there would be a high demand for sled dogs. Such a magnificent specimen as the one-hundred-and-forty pound Buck. And, that he would easily revert to his more atavistic nature is also realistic as feral dogs quickly develop shorter, thicker coats and run in packs like their ancestors did.
As Buck and another large dog, a Newfoundland are put upon a ship bound for Alaska, Buck realizes that his captors
...are a new kind of men...and while he developed no affection for them, he nonetheless grew honestly to respect them.
Once in Alaska, Buck further discovers that men and dogs are both little more than savages in this raw land, with no law but the law of force ruling their lives.