They need it to survive because they need it to both find food and avoid becoming food, which was my main point. That's why you see things like plants or filter feeders usually only having a nerve net or completely forgoing any complex brain.
Asking why they even evolved is a super moot question like why did some things stay in the water and some things colonize land? Because something did and then everyone else did after that.
Specifically for the sponge question though it's not always the best to be a sponge. You have to live in an environment with a lot of free floating food.
Bentley Parker
You got it backwards.. Beacose so many life-form survive without it, intelligence is rare. It has advantage in the long run, but considering how energetically inefficient it was in early humans is incredible we actually got to where we are.
Carson Reed
This Brains cost calories to run and humans take forever to develop enough to fend for themselves.
Parker Garcia
You're actually really close to the truth.
In biology, we call the ability to handle a wide variety of environments, and a large resource niche by a property called "plasticity". Basically, it's any adaptation that allows for changing without relying on evolution to fit an environment. Sometimes, plasticity is a pretty simple mechanism, like the ability to shed so you can have periods of the year where you are warmer, and periods where you are colder- this is an adaptation that allows for greater survival in multiple environments. Intelligence, along the same vein, is an adaptation that allows the animal to take in data, and respond accordingly in a more temporal sense.
Think of how neurons typically work, and how we might talk about a worm moving in response to some discomfort like an extreme temperature gradient, or a physical poke. It's not like they're necessarily "thinking", but that their nerves are direct sense -> action units. Even in mammals we have plenty of those- the most classic example being the knee-jerk reflex, where sensory neuron goes straight to an interneuron going straight to the muscle, without going to the brain.
By being able to 'store' signals temporally with an intelligent brain, animals can essentially respond in much more complex ways, based on all of the senses of past and present. Not to delve too deep into epistemology, but it really does work like that with respect to how humans think, act, and know as well. Imagining how a simple intelligence could become more complex over time doesn't seem too difficult if you know how natural selection and evolution work, and from there it's simply a question of what genes and structures are involved. For those, I saw a thread up on the genes of intelligence (though haven't confirmed if it was /pol/bait yet), and there's a good thread on the effort to map neurons called the connectome up right now if anyone's interested in this kind of thing.
Alexander Hughes
That's cool user. Topics like this kind of scare me and make me wonder whether free will or the self exists. It seems to me like we're just emergent phenomena of nature, similar to a wave, mountain, blade of grass, tree, or lower animal. Just a part of the universe. Obviously we are part of the universe. Lol this is the type of thing that simultaneously sounds deep but is also kind of obvious and /r/iamverysmart. But damn.
Jack King
>why is intelligence even selected for survival when some many lifeforms do so well without it?
Because it's a useful trait to be able to coordinate and manipulate your ecosystem. The problem is that Humans eventually managed to receive to much of it with no other species to challenge said dominance. The most basic primitive human tribes can out perform other species to near extinction if they aren't careful. While the most advance human societies can wipe out entire ecosystems with little thought.
We've long pass the maximum intelligence threshold required by us from nature (at least on earth). Even arbitrary use of fire and recording text breaks natural hierarchies in half in all regions with only disease and weather being to main danger.
At this point selection for intelligence is mostly for
Sebastian Foster
*At this point selection for intelligence is mostly for ornate purposes.
Leo Parker
Hey man, explore those kinds of thoughts. They can be really scary or depressing, and represents a sort of nihilism that comes from scientific knowledge of the nitty-gritty makeup of life. That doesn't mean it's bad, and often you end the journey with a profound sense of meaning- even if it's the meaning you ascribe life, rather than any inherent meaning.
Striving to know more is always a wonderful thing!
Nathan Diaz
different user
look up rubber hand experiment, depersonalization disorder, and if you find that type of stuff interesting read The Ego Tunnel by Thomas Metzinger
Probably because intelligence wasn't as useful for survival as other traits were. And even if it was, a big brain requires a lot of energy which might be better of used on something else.
Humans could evolve big brains after figuring out how to cook food and get way more energy than they needed
