Natural Selection Seems Insufficient

[The Grand Nudger]

It means that, if the species is to survive,  blind causality must move the mammal towards food and drink, and force it to ingest this sustenance, on a regular, timely basis. And not too little, and not too much, e.g. drinking too much water at one meal can kill you, it happened a while back to a mother of two. 

Haven't we already discussed this?  Hunger is -exactly- the sort of homeostatic trigger that causes us to eat too much.  It's why we find ourselves chronically obese in todays world, as opposed to the world our hunger response developed in.

It is true, fwiw, that life doesn't need a hunger response (like ours, or at all) to stay alive. Plenty of life doesn't work the way we do. We're extra like that - not unique in this respect, but still pretty cool. There are also some genuinely baffling unknowns in this AO. We don't know why dodder vines will pass up suitable host plants in search of others - a behavior that leads to most of the dodder vines that germinate dying. When we try to describe it we end up talking about preferences, plants with preferences. Preferences they'll die over. Stranger than we can suppose, I guess....but here's the kicker, this seemingly inexplicable and far too familiar state of affairs would appear like it would be an issue for dodder vines..but it isn't. They're an invasive species. Doing extremely well....not in spite of this suicidal impulse, but because of it. They spread further, faster, than they otherwise might if they attached to the first suitable host. From our point of view it looks like they're searching for tomatoes..but maybe they're just going the distance, and solanae voc are strong airborne reactors - a solid orientation signal.