Religions evolve, not metaphorically, but in a very real way. By applying "survival of the fittest" principles to religion, we can finally understand how religion became incredibly infectious to the average human, perfectly adapted to its "environment," your mind. Infectious ideas like the loving, personal father-figure God, the promise that death is not the end, the attraction of heaven, the threat of hell, and many others, are traced from prehistoric to modern times, to show why they survived while thousands of other ideas died out. The world's religions have amazing parallels to biological life: They reproduce, mutate, and compete with each other in an ongoing battle for the survival of the fittest.
