- The Control Voice: What makes us human? Is it our basic instincts or our noble aspirations? Are we slaves to our genetics or masters of our fate?
A scientist experiments on himself and starts turning into a caveman.
- The Control Voice: Perhaps we can never fully escape the animals we once were, but with our minds and our hearts, we can always fight to remain human.
- Devolution Device: Dr. Arthur Zeller is a submissive, unassertive anthropologist who is mocked and taken advantage of by almost everyone. He often admires the university's exhibit on Homo erectus and wishes that he could emulate the dominant behavior of early man. Arthur develops a DNA serum which is designed to make the subject more dominant and successfully tests it on a mouse. He then decides to inject himself with it. The change is immediately apparent as he becomes more assertive and aggressive at work. There are also numerous physical alterations. Arthur finds that his mind occasionally reverts to that of a Homo erectus. After his proposal for a new project is rejected by the head of the anthropology school Professor Martin Standfield and he is suspended for his erratic behavior, Arthur savagely beats Standfield in the car park. He then injects his colleague Dr. Laura White, for whom he has feelings, with the serum as he believes that this is the only way that she will respect him but the transformation process does not take hold in her case. When he finally admits what he has done, Laura's tests show that his cerebral cortex is shrinking and his skeletal structure is undergoing major changes. Arthur eventually reverts to a complete specimen of Homo erectus and is placed in the university exhibit.
- Monster Munch: A slight variation as it is the protagonist, Dr. Arthur Zeller, who kills and eats a dog while in the process of transforming into a Homo erectus.
- Precision F-Strike: Arthur delivers one to Jim when he praises him for standing up to Professor Standfield.