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grandtheftbonsai t1_j9shy0x wrote

First, one has to define thinking and intelligence.

Animal scientists have argued this for ages. Surely monkeys are intelligent, as are dogs and cats. What about monotremes? Fish? Sharks? Lamprey? Starfish? Worms? Insects? All of these have a centralized nervous system. Is that the definition of intelligence. Jellyfish have nerves, but no centralized processing facility. Are they intelligent or do they just react? Sponges (the most ancient extant animal) have no nerves. Are they intelligent?

Plants communicate with each other warning of herbivory, within and between species. Is that intelligence?

Slime molds live as unicellular organisms when food is abundant, only to group up in worm like structures to search for greener pastures. If not found, they metamorphose into what resembles a fungal fruiting body? So are they unicellular or multicellular? Is that intelligence?

Intelligence is a human derived construct, not easily applicable to the vast diversity of living organisms.


Shadowwynd t1_j9t68zj wrote

Slime molds can also solve advanced mazes. I would posit this is intelligent behavior - problem solving - without neurons.

There is also the researcher who built a roller coaster for her mimosa plants - the first few times the plants freaked out and closed up, then they realized “no biggie” and were fine with it - at some level they learned and remembered without neurons.


f_leaver t1_j9tpxyq wrote

Even more impressive to me is the pea plant who learns to follow a fan in the article you linked.


FogeltheVogel t1_j9tquoo wrote

How does it even notice the breeze in the first place?


LordFoulgrin t1_j9tzkfw wrote

TL;DR at bottom

Plants "respond" to stimuli through a process known as tropism, and two or possibly three of these stimuli are present: thigmotropism (response to movement or touch), phototropism (response to light), and chemotropism (response to chemical stimuli; I list this one as UV light may breakdown substances on the surface of the plant to trigger a response).

These responses aren't so much a thought process as much as a reflex, such as if your knee reflex triggers without thought if hit in the right spot. Plants responding to these stimuli have what I'd describe as spring-loaded traps on the surface of each cell, ready to trigger with the right application. It is much like cell receptors waiting for a specific hormone to bind to a site before expressing a response.

When that trigger is met, a group of ions makes it way down a pathway to make a cell to increase it's uptake of water or decrease its uptake (this is through osmosis, and creating a hypotonic or hypertonic environment in the cell). When you have groups of cells in one region suddenly increase their water uptake and others decrease the amount they hold, the plant will flex in a certain direction, resulting in plant movement. These movements usually aren't drastic as with specialized plants like touch-me-nots and Venus flytraps. With the pea plant it would occur over hours.

Interesting to note that touch response can also influence the final structure of a plant, where it will alter how it grows , known as thigmomorphogenesis. These growth response are exaggerated at the tips of roots and tendrils, or meristems. This is how you will find trees that have branches arranged around structures or influenced by wind.

TL:DR: plants have specialized receptors for light, touch, and chemicals that tell groups of cells to increase or decrease water uptake making the plant bend.


FogeltheVogel t1_j9u0yy3 wrote

This all sounds like it's very much an analogue to nerves and muscles.

Do plants then just have their own versions?


LordFoulgrin t1_j9u2zmu wrote

TL;DR at bottom again.

Not quite, though one could argue the result is the same for basic tasks. Plants have no muscle or nerve system in a traditional sense. Plants use their cell walls to do this, which animal cells lack, possessing only a membrane.

The responses to stimuli and ion flow in a plant happen on a cell to cell basis, though cells can communicate through tunnels in their cell walls, known as plasmodesmata, and I'm sure you could find studies where hormones diffuse into neighboring cells.

Muscles move by having ropes of cells packed very thickly together, and shorten or lengthening by having millions of microscopic hands working together to pull along/against surrounding muscle cells (this is a layman's allegory, if you want a more in-depth look, search cross-bridge cycling in muscular tissue). Plants, as stated before, rely on water pressure in cells to flex their wall filaments in certain directions, more akin to how hydraulics work.

TL;DR: Plants do not have muscles or nerves, but can appear to accomplish tasks in a different manner.


FogeltheVogel t1_j9u9l3z wrote

I'm a microbiologist, so I knew at least some of these on the eukaryote side, but I've never really looked at plants before.


riuminkd t1_j9tl1h6 wrote

Do you realize that "slime mold solving maze" is literally just following the steepest gradient of smell/taste of whatever it is in the middle? There is no intelligence involved. And i don't think memory is considered to be a sign of any high intellogence


MayorOfNoobTown t1_j9tycmn wrote

> And i don't think memory is considered to be a sign of any high intellogence

Really? Every model of intelligence I'm familiar with includes memory as a significant component. Without some form of memory, one is unable to make predictions.

Without predictions, one is restricted to a completely static reactionary model. Iteration is impossible without memory.


jqbr t1_j9vk5uu wrote

> Every model of intelligence I'm familiar with includes memory as a significant component

Fallacy of affirmation of the consequent. Intelligence is a sign that there is memory, not v.v.

P.S. No, I did not commit a fallacy of denying the antecedent (which is the contrapositive of and thus logical equivalent of affirmation of the consequent), and it's not a game. And you just committed the same fallacy again ... yes models of intelligence include memory -- that's what I said. But memory does not entail intelligence -- again, that inversion is your fallacy.


MayorOfNoobTown t1_j9vx6qc wrote

Well, if we're playing the fallacy game, you've just committed the fallacy of denying the antecedent.

It's true that intelligence doesn't necessarily guarantee the presence of memory, you'll be hard pressed to find a serious model that omits memory as an essential component of the ability to learn from experience and apply that knowledge in new situations.


Krilion t1_j9uuj8p wrote

You actually missed the real criticism, in that it's more or less a optimized maze search shortest path algorithm, which can be selected for chemically.

But uh, that's all biology is, including neurons. So the line still exists. The question isn't "Is finding the maze high intelligence?" It's "Where do you put the arbitrary line?".


riuminkd t1_j9uv5i2 wrote

It's not an optimized search algorithm. It's literally "spread yourself in all directions, once food signal from one of your sides gets sufficiently strong, shift your body in this direction". It's bruteforce. And no one will put arbitrary line that close to complete unintelligence


Krilion t1_j9uwclf wrote

Hey, uh... What do you think maze solving algorithms do?


riuminkd t1_j9uxg2i wrote

Don't those usually refer to single entity traversing maze? Not something that can just grow in all directions


Krilion t1_j9uxz04 wrote

The process for finding a specific random point in a maze usually involves 75%+traversal. It doesn't matter if you're a single entity or not, as the slime mold is just effective running it all in parallel.

Even given the location of an exit, most solvers still end up searching most of the map before finding it.


Bax_Cadarn t1_j9u2js5 wrote

Do You realize that our solving a maze is just following what we see?

Do You realize a rat solving a maze could do that just by smelling food or from memory?


Shadowwynd t1_j9wjjdb wrote

A nerve cell is following similar gradients of chemicals. Where do we draw the line for intelligence? The OP question was about intelligence not using neurons. Is problem solving intelligence? Is maze solving a chemistry trick given life itself is a chemistry trick?


riuminkd t1_j9xngp6 wrote

We do not consider single nerve cell as possessing intelligence. And again, mold doesn't solve maze. It isn't even aware of maze. It is following a rigid and very simple program. If you draw the line of intelligence here, literally all living beings are intelligent. And all computers too


pandc0122 t1_j9ug2ld wrote

“Following the steepest gradient of smell/taste of whatever is in the middle?”

How does that differ from any other problem-solving animal?


riuminkd t1_j9ui51x wrote

For problem-solving animal, it is not seen as sign of intelligence. Imagine if people were saying that "dogs are intelligent, just look at them finding food via smell!"


pandc0122 t1_j9ujjzr wrote

I get that, but by itself, and using the same example, it is also not evidence of the absence of intelligence.


jqbr t1_j9vky7v wrote

Strawman ... no one came anywhere near to saying anything about evidence of the absence of intelligence. A claim that X is not evidence of Y is very different from a claim that X is evidence of not Y.


aggasalk t1_j9uxqcp wrote

you can also very easily write a computer program to solve a maze, but most of us would be reluctant to attribute "thinking" or "intelligence" to the program, or the computer running it (except in a very casual sense of the word - like, the computer's taking a while to do something, we might say "it's thinking", but it's not really thinking).

in the case of computers, we're applying our own psychological concepts to phenomena where they're only appropriate at an extrinsic, 3rd-person point of view - from the outside, what the machine is doing looks like what the intelligent organism does - while what's actually happening in the system is absolutely unlike the psychological phenomena on which those concepts are based.

by a classic analogy: just as a computer simulating a hurricane isn't windy or wet, a computer simulating a mind isn't thoughtful or intelligent.

i think the same applies to plants, slime molds, etc - they aren't simulating, that implies some kind of intention, but what they're doing only appears like intelligence because it happens to resemble the behaviors that we associate with actual thought.


boomchacle t1_j9ty2np wrote

The fact that the plant “remembered” the ride after 2 months is pretty impressive.


nicuramar t1_j9vv5of wrote

> Slime molds can also solve advanced mazes. I would posit this is intelligent behavior

Fairly simple algorithms can as well, but we wouldn’t call them intelligent.


slomobileAdmin t1_j9uv2a6 wrote

There are examples within our own bodies linked to, but distinct from the nervous system.

A jellyfish reactionary sting and a plant seeking sunlight are also a type of problem solving. Continuing to live always involves some type of problem solving. Reproduction solves the problem of continuing to exist in some form even after death. Evolution is problem solving. Is a "living planet" intelligent, or even alive at all? When a magma chamber is infiltrated by ground water and explodes into a volcano, is that pressure relief problem solving or just the net result of physics? Is intelligent thought also the net result of physics?

Given humans are intelligent, what is the smallest portion of a human that is still considered intelligent in its own right? Can it be neurons alone? If not, then you have an example of non-neuron biological "intelligence" in whatever else, besides neurons, is required.

Are we still intelligent while we are sleeping?

Prediction, without memory, can occur if the intelligence is built into the machine.

A jellyfish probably isn't aware that its involuntary reaction predicts its survival.

Who or what built the intelligence into the jellyfish machine?

Where is there evidence of intelligence? In the blueprint.


chatongie t1_j9so32h wrote

I was thrilled to see that we're getting closer to the definition of intelligence bit by bit (here the emphasis should be on "bit by bit") when I first learned the notion "Relevance Realization". A guy called John Vervaeke does a very good job in explaining it.


Mkwdr t1_j9suos9 wrote

I know nothing - in no way an expert but i would hazard that there is a definite gradient in intelligence/consciousness/self-awareness etc beginning with very simple immediate input-response with no significant ‘processing’ to neural networks that take inputs and build models of external reality mediating possible responses to those that build more complex models allowing greater flexibility and even models of the models/modeller. I wonder if self-consciousness is a sort of internal experience of a model of the models or model of the modeller. But no doubt rather like the concept of life itself these are difficult concepts to be entirely precise or draw definitive lines about. And obviously we should be careful about considering potential variety in something like intelligence because there are perhaps arguably creatures with complex but niche limited intelligence and those with more flexible wide-ranging, I think. It’s easy to see ourselves at the top of every gradient but that may be in the sense of plasticity (?) and range rather than in specific niches. If that makes any sense at all!


TikkiTakiTomtom t1_j9tylzy wrote

But in essence. To “think” requires neurons. The answer would be yes. All things that think has neurons.


Uncynical_Diogenes t1_j9vmd2x wrote

Slime molds can, without your definition of “think”, design more parsimonious subway networks than I can, and I have a whole advanced primate brain I think with all the time.

Where do you draw the line between thought and intelligence? Abstract thought? Because no amount of abstract thought will make me better at designing the Tokyo subway system.


Training_Ad_2086 t1_j9sq7nd wrote

Sapience and sentience is what you are looking for.

Most animals are sentient but not all sentient animals are sapient.

An ape can realize its him in the mirror while a goldfish can't

As of non biological neurons, computer simulated neural networks are the closest thing. But they are neither sentient nor sapient yet.


Puppy-Zwolle t1_j9v992x wrote

Neurons are among the oldest cells evolutionarily speaking. If you go beyond small clusters of cells you need a way to get signals across your organism. Short distances? No problem but larger distances or more complex instuctions, or better timed reactions you need 'cable'. Enter the neuron.

So basically neurons developed into 'intelligence' from a 'need' to communicate internally. From this you can evolve stuff like bigger muscles, legs, arms. Brain.

So unless we discover intelligence in plants I'm afraid neurons are the only way to go.