Harding explains to Ellie the mechanics of the dinosaurs’ vision that Grant already discovered experientially: the dinosaurs are more attuned to movement than any other visual stimulus. Although this represented the cutting-edge paleontological theories of the time of the book’s publication, subsequent research has disputed this hypothesis. Regardless, the apatosaurs’ disinterest in the humans parallels the park operators’ disinterest in attending to the facts available to them about their work. And while the humans don’t mean anything to the giant dinosaurs, unfortunately, the unforeseen variables affecting the park do have real consequences.