In Apartheid-era South Africa, a scientist uncovered a cracked, proto-human jawbone. That humble fossil would go on to inspire one of the most blood-spattered theories in all of paleontology: the “Killer Ape” theory.  According to the Killer Ape theory, humans are killers—unique among the apes for our capacity for bloodthirsty murder and violence. And at a particularly violent moment in U.S. history, the idea stuck! It even made its way into one of the most iconic scenes in film history. Until a female chimp named Passion showed the world that we might not be so special after all.