I wonder if the carrots were implemented as a means of encouraging doing more of the thing than the organism would do otherwise. If there were no carrot aspect to hunger, the organism would only eat just enough to stop the pain of hunger but no more, missing the opportunity to build up fat stores for the future. If there were no carrot aspect to peeing, the organism would expel just enough to make the pain go away but wouldn’t empty the tank, so to speak, making them carry around some tiny amount of extra weight than otherwise. This might be a just-so story, but it’s the answer that comes to mind for me.
I wonder if the carrots were implemented as a means of encouraging doing more of the thing than the organism would do otherwise. If there were no carrot aspect to hunger, the organism would only eat just enough to stop the pain of hunger but no more, missing the opportunity to build up fat stores for the future. If there were no carrot aspect to peeing, the organism would expel just enough to make the pain go away but wouldn’t empty the tank, so to speak, making them carry around some tiny amount of extra weight than otherwise. This might be a just-so story, but it’s the answer that comes to mind for me.