Evolution is the only theory that science hasn't rejected For the origins of life, and humans are no exception And if behaviour has a genetic basis and it's naturally-selected Then human nature hasn't changed since the days of Homo erectus The modern-day skull houses a stone-aged mind 'Cause achieving major change in a chromosome takes time You know how kids like sugar on their cornflakes right? Well, that's evolution in action – we can follow a straight line Back to our ancestors' food preferences and incest-avoidance And mate preferences, and aversion to ingesting poisons Evolution even explains why the female chest is so boisterous So if you think human nature is flexible, get set for disappointment 'Cause selfish genes lead to selfish behavior And alpha males impregnate the wives of their helpless neighbors Human beings are socialized to deny their hellish natures But we might as well embrace it now, and deal with the outcome later