I was wondering: what exactly is the reason that things die? There seems to be quite a few benefits if organisms did not die as often... but I suppose there must be some reason? If it's to re-fertilize the Earth, making a species less fertile would work just as well. Secondly, what would be a reasonable way to have a character gain a symbiotic partner? Somewhat of a Spider-Man/Venom/Carnage creature, but a little less crazy. (notice I said a 'little'.) My story takes place on a different planet, but I also want to keep others away from the potential power.