civilization
civilization pops up where there are enough free resources around that folks can invest in a few freeloading scientists. they invent a few things that improve the quality of life ie lower the death rate. this results in more people. but that's okay. the scientists figure out how to feed them until our birth rate can adjust. so now we have many well fed people ie soldiers with which to spread our way of life to our neighbors. their death rate goes down. but they don't make the same investment in education as we do ie their birth rate stays high. eventually there are so many of these dumb rabbits that they take over. but they can't maintain the technological advances our society needs to survive. so it collapses.