Darwin's "Gotta Catch 'Em All" Theory began to take shape after Darwin observed what he called "evolution" in various species of animals, particularly in the Galapagos. Darwin's theory of natural selection and survival of the fittest soon followed logically into the Gotta Catch Em All Theory. The theory states that in order to facilitate and speed the process of evolution, one must capture animals and force them to duel, therefore killing off weaker species so that the strongest rise up in the evolutionary chain.