We effect animals by just going about out daily lives. We plant food for the herbivores to eat, which the carnivores then eat, and then the omnivores (us) eat them. Also, pollution can affect animals...
Art jargon is silly, isn't it, just! Modern, of course means "happening right now" and so if it meant anything at all, post-modern would mean "happening more recently than right now," which is...
the answer to your first question is that without nuclear fusion in the heart of stars there would only be the most basic elements like hydrogen and helium. other elements such as carbon are made...