Nature doesn't decide anything. Creatures that have traits which give them an advantage, however slight, in terms of survival and reproduction, get the chance to live long enough to be sexually selected, reproduce and thus pass on the genes responsible for those traits. Nature is a filtering process, not a guiding intelligence. There's a lot more to it than that, but those are essentially the basics.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'
