Biological organisms are machines for turning energy into additional copies of the genes that created the organism. People in the developed world have access to

Biological organisms are machines for turning energy into additional copies of the genes that created the organism. People in the developed world have access to an obscene amount of energy. Yet fertility rates are below replacement level in basically every developed country (if you don't count first generation immigrants). And when you zoom in, you notice that poor people have more children than all but the top several percent of earners (so fertility goes down as access to resources goes up). If you saw something similar in any other species, it would be the biggest unsolved riddle in biology. Something truly strange. And yet here we are basically not paying attention to it at all.