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April 22, 2009 8:55 AM   Subscribe

Slime Molds Show Surprising Degree of Intelligence - A creature with no brain can learn from and even anticipate events. (via)
posted by kliuless (59 comments total) 16 users marked this as a favorite

 
Yeah, whatever. Until Physarum grow thumbs and can hold a gu-OMG IT'S EATING MY ARM
posted by Brandon Blatcher at 9:01 AM on April 22, 2009 [8 favorites]


Slime molds are not actually molds!

Boy I'm smart.
posted by Mister_A at 9:03 AM on April 22, 2009


It lacks the five-fold symmetry that all proper intelligent beings have.
posted by Artw at 9:03 AM on April 22, 2009 [1 favorite]


Except for those Wall Street slime molds, which apparently do not share the same genes.
posted by weapons-grade pandemonium at 9:04 AM on April 22, 2009 [2 favorites]


Fourth link: For many millions of years, rock ants have used a mathematical trick that was only discovered by humans in 1733. Rock ants can estimate the volume of a space, even an irregular shaped one, by randomly laying a scent trail across the floor of the space, "recording" the length of that line, and then counting the number of times it encounters that scented line during additional diagonal runs across the floor. The calculated area is inversely proportional to the frequency of intersections times length. In other words, the ants discovered an approximate value for Π derived by intersecting diagonals. Headroom is measured by the ants with their bodies and then "multiplied" with the area to give an approximate volume of their hole.

Whoa, that's some intelligent design going on there.
posted by Brandon Blatcher at 9:04 AM on April 22, 2009 [1 favorite]


Wall Street slime molds don't share anything, weapons-grade pandæmonium.
posted by Mister_A at 9:05 AM on April 22, 2009 [1 favorite]


This mean we now get more XP, right?
posted by zerokey at 9:08 AM on April 22, 2009 [2 favorites]


Yup. They're still highly resistant to attacks with edged weapons though.
posted by Mister_A at 9:10 AM on April 22, 2009 [6 favorites]


"A creature with no brain can learn from and even anticipate events."

What? Bush was the exception?
posted by HuronBob at 9:17 AM on April 22, 2009 [2 favorites]


I find this link amusing in light of the current on-site no-brain baby contretemps.
posted by mwhybark at 9:19 AM on April 22, 2009


IIRC it was nematode worms in that issue of Swamp Thing.
posted by Artw at 9:23 AM on April 22, 2009


For an organism that evolved on a planet that has varying periods of light/dark and heat/cold, you would almost expect this. Still pretty nifty, though.
posted by kuujjuarapik at 9:24 AM on April 22, 2009


Ants can do more advanced math than I.

Great.

Thanks for the post, mister ego-killer.
posted by mr_crash_davis mark II: Jazz Odyssey at 9:29 AM on April 22, 2009 [3 favorites]


this link on fungal intelligence seems relevant here. (google groups)
posted by oonh at 9:31 AM on April 22, 2009


Slime molds are the only remaining Terran lifeforms. Everything else, you, me, birds and bees and sycamore trees? Aliens. DNA from the dying Mars, seeded here by a massive asteroid impact and triggering the Precambrian Explosion.

So, be nice to the Slime Molds, they're still a little bitter about it.
posted by The Whelk at 9:37 AM on April 22, 2009 [2 favorites]


I, for one, etc etc
posted by fearfulsymmetry at 9:37 AM on April 22, 2009 [2 favorites]


The description of slime molds as "single-celled organisms" is correct, but pretty misleading. Physarum, the slime mold in that article, is a slime mold that contains thousands of nuclei in a single cell. So yeah, it's technically a single cell, but it's actually about as advanced as a simple multi-cellular organism.
posted by explosion at 9:45 AM on April 22, 2009


Ants can do more advanced math than I.

Ah, but can ants boil a kettle? That'll shut them up.
posted by Artw at 9:51 AM on April 22, 2009 [2 favorites]


All I know about slime molds is that they taste great and are quite satiating for their weight.
posted by cotterpin at 9:59 AM on April 22, 2009 [2 favorites]


oonh: What an amazing thing to read. Thank you for that.

got any shrooms? /joke
posted by hippybear at 10:01 AM on April 22, 2009


Pssst! -- nobody tell them about ochre jellies...
posted by LordSludge at 10:02 AM on April 22, 2009


After reading up, the FPP is a little misleading.

OP says that slime molds can "learn" and links to some sort of blog post that uses as evidence that slime molds can navigate a maze "like a rat". I found this fishy so did some research; it isn't true. The slime mold colony is placed at various points in the maze with food at both exits and then expands to fill the entire maze in slime-mold-like fashion. Once it fills the entire maze and thus finds both piles of food, it retracts itself from the dead-ends and longer paths.

That doesn't require intelligence. An organism doesn't need a brain or the ability to think or reason for its body to tell whether it is gathering food in an efficient or inefficient manner, and it just gives up on the parts that are supplying food inefficiently.

The bit about anticipating future events has to do with response to cold stimuli. That one is a little more interesting. Plants do something similar and we don't consider them intelligent, but the slime molds did seem to learn the behavior in at least a superficial sense, so I'd have to think about that further but my instinct is, again, that it is some sort of autonomous response.
posted by Justinian at 10:07 AM on April 22, 2009 [3 favorites]


my instinct is, again, that it is some sort of autonomous response.

Wouldn't having an autonomous response which didn't exist before be a form of learning? Especially when that response can be malleable, as indicated in the article?
posted by hippybear at 10:17 AM on April 22, 2009 [1 favorite]


Is our houseplants learning?
posted by Artw at 10:24 AM on April 22, 2009 [2 favorites]


The slime mold colony is placed at various points in the maze with food at both exits and then expands to fill the entire maze in slime-mold-like fashion. Once it fills the entire maze and thus finds both piles of food, it retracts itself from the dead-ends and longer paths.

That doesn't require intelligence. An organism doesn't need a brain or the ability to think or reason for its body to tell whether it is gathering food in an efficient or inefficient manner, and it just gives up on the parts that are supplying food inefficiently.


Just to butt in for a second, Justinian. Couldn't you reasonably make this argument about any seemingly intelligent behavior?

The particular problem-solving approach the slime-mold takes--exploring every possibility by brute force before adopting the approach that most directly achieves a goal--is a problem solving strategy also frequently employed by "higher-reasoning" organisms like ourselves.

Where do you suggest drawing the boundaries between "autonomous response" and intelligence? Without adopting some variation on dualism, at some level, all intelligent behavior is merely a consequence of a series of physical processes playing out according to either deterministic principles or random chance. The chain of processes leading from a stimulus to a resulting behavior might be more or less elaborate, more or less efficient, but ultimately, this chain of physical processes is itself unintelligent. Intelligence is an emergent property of unintelligent physical processes.

What's true of slime-mold intelligence is true of human intelligence (though not necessarily the inverse). The physical mechanisms of human intelligence are just more cleverly hidden. Or alternatively, some variation on dualism is correct.
posted by saulgoodman at 10:44 AM on April 22, 2009 [3 favorites]


I, for one, OH HELL NO.
posted by louche mustachio at 10:55 AM on April 22, 2009 [2 favorites]


Well, they did a fairly good job with all the teabag parties.
posted by PlusDistance at 11:10 AM on April 22, 2009 [2 favorites]


The particular problem-solving approach the slime-mold takes--exploring every possibility by brute force before adopting the approach that most directly achieves a goal--is a problem solving strategy also frequently employed by "higher-reasoning" organisms like ourselves.

Sure, but higher-reasoning organisms like ourselves can use other approaches and can choose to use whichever approach we feel will be most effective. A slime mold has no other approach but brute-force. It doesn't choose to use brute force, it just grows and grows and grows because that's all it can do.

Where do you suggest drawing the boundaries between "autonomous response" and intelligence?

I'm not sure. Which is why the other example of a slime mold apparently "learning" that it will get hit by a cold snap for 10 minutes every hour and preparing for it in advance is more problematic to me. I'd have to consider it more deeply to come up with an explanation; the maze problem is trivial by comparison.

It occurs to me that Peter Watts' excellent Hugo-nominated novel BLINDSIGHT deals with some of these issues. It has to do with the differences and interactions between consciousness and intelligence. Scary stuff.
posted by Justinian at 11:22 AM on April 22, 2009 [2 favorites]


The physical mechanisms of human intelligence are just more cleverly hidden.

Forgot to add; one could say the same thing about plants and humans. Plants grow towards the light, after all. Move the light to the other side of the plant and it will start growing in the other direction.
posted by Justinian at 11:23 AM on April 22, 2009


You say slime mold, I say shoggoth.

That said I agree with Justinian - I've done labwork with Physarium (years ago) and while they are endearing, they're not much more smart than a plant seeking light.
posted by Weighted Companion Cube at 12:21 PM on April 22, 2009


I agree, Justinian--in fact, I've often wondered just what it means for theories concerning the evolutionary significance of intelligence that so many seemingly non-sentient lifeforms like plants, fungi and other organisms display such a high degree of adaptive fitness. There are molds thriving in places mammals wouldn't dare go, fungi that feed on radiation.

So what is intelligence actually necessary for, in evolutionary terms? I can't imagine a single argument that doesn't fail miserably in the face of an actual reality in which we are vastly outnumbered by creatures we don't consider intelligent who are nevertheless not only surviving but thriving in the world right now.

It seems to me that, given the facts as they are, we've either got to revise our conception of intelligence, or conclude that intelligence isn't really a necessary adaptation from an evolutionary perspective. In taking the former position, I might argue that the slime-mold is displaying at least a limited form of intelligence, and that any differences between slime-mold intelligence and human intelligence are really only a matter of extreme differences in degree rather than differences in kind.
posted by saulgoodman at 12:24 PM on April 22, 2009 [1 favorite]


Sure, but higher-reasoning organisms like ourselves can use other approaches and can choose to use whichever approach we feel will be most effective. A slime mold has no other approach but brute-force. It doesn't choose to use brute force, it just grows and grows and grows because that's all it can do.

But we are limited in many other ways, and we aren't even aware of them. We have defined intelligence as 'what people do' (in fact that used to literally be the definition), and it makes us uncomfortable to think that there might be more to it, but there it is. Based on what we now know the nature of life to be, it seems to me that life itself IS intelligence, and all further differences are matters of degree.
posted by showbiz_liz at 12:27 PM on April 22, 2009 [1 favorite]


only a matter of extreme differences in degree rather than differences in kind

Dang it saulgoodman
posted by showbiz_liz at 12:28 PM on April 22, 2009


You know what else showed a surprising degree of intelligence?

OCTOHITLER
posted by Mister_A at 12:36 PM on April 22, 2009


> A creature with no brain can learn from and even anticipate events.

Look for the 2012 television smash hit "Were They Smarter Than A Slime Mold?" Instead of a game show format in which adults answer questions posted by slime molds, the ability of the Slime Mold to learn from and even anticipate events will be compared and contrasted to the Bush administration's ability to do the same.
posted by The Card Cheat at 12:48 PM on April 22, 2009


Can we PLEASE stop posting about Sarah Palin?!?!?!
posted by briank at 12:55 PM on April 22, 2009 [1 favorite]


So, then, does learning always connote intelligence? I think that is the question.

I say, no. Non-intelligent living things can learn, as the slime mold in the article does. It learns that once an hour things get cold. That's not an intelligent thing, it's conditioning, but that's still learning.

Now, as far as how the slime mold knows when an hour has passed? I cannot account for that.
posted by hippybear at 1:00 PM on April 22, 2009


Just wait until slime mold's around the world launch a coordinated attack
posted by Joelogon at 1:10 PM on April 22, 2009


saulgoodman: "So what is intelligence actually necessary for, in evolutionary terms? I can't imagine a single argument that doesn't fail miserably in the face of an actual reality in which we are vastly outnumbered by creatures we don't consider intelligent who are nevertheless not only surviving but thriving in the world right now. "

Well... what are stripes necessary for? I'd argue something to the effect that intelligence conveyed an evolutionary advantage within a certain environs, but it's not really required per se. Merely that within a given biome (i.e. where "intelligence" first arose) it did give a "leg up" as it were. What kind of intelligence are we referring to. Any intelligence? Human intelligence?

Now that I'm thinking about it, there is a lot to mull over, I guess. But I still think it provided an advantage when it arose (and continue(s/d) to)...
posted by symbioid at 1:15 PM on April 22, 2009


It seems to me that, given the facts as they are, we've either got to revise our conception of intelligence, or conclude that intelligence isn't really a necessary adaptation from an evolutionary perspective.

This is even more on point with Watt's BLINDSIGHT. But it would be massive spoilers to explain it.
posted by Justinian at 1:42 PM on April 22, 2009


The neighbors had some slime mold on their lawn last summer. I couldn't for the life of me figure out what it was, so I did some internet sleuthing. I ended up reading about the stuff until like 4am, because it's fascinating.

Thanks!
posted by shakespeherian at 1:51 PM on April 22, 2009


boundaries between "autonomous response" and intelligence

Agree w/SG that the latter would seem to be only a conceptually over-burdened term for the former, with one caveat: freedom/self-agency/creative necessity.

Let us call this F-SA-CN, and let me say that a) I don't think I'm being naive in thinking we possess something like it, and b) I don't think I'm being anthropomorphic in thinking slime molds do not have it. I also think it is only a difference in degree, and not in kind: plants display something like intentionality when their leaves bend towards the light, but pansychism aside I don;t think plants possess anything like a mind or self-awareness.

One can read in thinkers like Spinoza, C.S. Peirce, Susan Langer, Gregory Bateson, and others, something like the meta-ecological view I am suggesting here: i.e. the view that "mind" exists on a non-hierachical and biosemiotic continuum, both functionally and ontologically, that stretches from simple single cellular organisms to complex human self-reflection.
posted by ornate insect at 1:54 PM on April 22, 2009


I'd argue something to the effect that intelligence conveyed an evolutionary advantage within a certain environs, but it's not really required per se. Merely that within a given biome (i.e. where "intelligence" first arose) it did give a "leg up" as it were.

I can't think of a single environment on earth in which humans or any other species we might ascribe human-like intelligence to have ever thrived more than plants, fungi or various types of microorganisms.

In fact, in every ecological system I can think of, all higher animals depend in one way or another for their survival on those lesser plants, fungi, and various other microorganisms.

So the continued survival and adaptive successes of non-intelligent species ultimately seems like a necessary precondition for our own survival. Our survival as an intelligent species depends on the survival of millions of dumb, heat-seeking worms squirming blindly in the soil. But this dependency is asymmetrical. We need the worms to survive, but the worms don't necessarily need us. Maybe the need for what we recognize as intelligence arose precisely out of this asymmetry, out of our dependence on other life forms to survive. (Unlike, say, plants, which may need nutrients, sunlight and water, but don't have to hunt or scavenge to create an ecological niche for themselves.)

To me, it's hard to draw any conclusions, but I'm inclined to think we just don't have clear enough ideas about what we really mean when we talk about intelligence.
posted by saulgoodman at 1:59 PM on April 22, 2009


our survival as an intelligent species

Cut away the word intelligent in the phrase above to realize that our survival depends quite literally more and more on the recognition that we are enviromentally bound as a species to the world as a whole. There is a very real possibility we will commit something like species eco-suicide if we do not implement a more sustainable kind of society.
posted by ornate insect at 2:06 PM on April 22, 2009 [1 favorite]


Hardly surprising.

"There are a pair of individuals in your apt," Lord Running Clam informed him. "It seemed to me you should be tipped off in advance."
posted by generalist at 2:08 PM on April 22, 2009


So what is intelligence actually necessary for, in evolutionary terms? I can't imagine a single argument that doesn't fail miserably in the face of an actual reality in which we are vastly outnumbered by creatures we don't consider intelligent who are nevertheless not only surviving but thriving in the world right now.

Not all creatures compete evolutionarily on the same terms. The basic goal of any living system is the acquisition of external resources (be they mineral, energy, or other living systems) for the purpose of self-perpetuation.

[Non-living processes like fire exhibit similar behavior, so this is not exclusively the domain of living systems, but all living systems fall within it]

There are many avenues towards the acquisition of resources. One avenue is to acquire resources in locations where other living systems competing for the same resources are unable to follow. Another, more common avenue is to seek the resource caches of the highest density: herbivores and carnivores consuming the gathered resources of other living systems.

Primate intelligence represents a variant of this approach: complex, adaptive behaviors for modifying one's own environment with the goal of consistent access to high-density resource caches. As a secondary benefit, better protection of their resource-investments in self-perpetuation: children.

Evolutionarily speaking, that is what intelligence is for.
posted by Ryvar at 2:10 PM on April 22, 2009 [1 favorite]


Sure, but higher-reasoning organisms like ourselves can use other approaches and can choose to use whichever approach we feel will be most effective. A slime mold has no other approach but brute-force. It doesn't choose to use brute force, it just grows and grows and grows because that's all it can do.

Once you bring in choice you get into the whole free will argument that never goes anywhere. There's a decent argument to be made that everything your brain does is a direct consquence of how your brain is wired and what stimulus you are exposing it to, so that "choice" is more or less an illusion.

I tend to like the Turing test definition of intelligence. It's hard to define intelligence in ways other than describing what humans can do that other animals can't, and if something other than a human can fake all of the things that make us intelligent then that's good enough for me to call it intelligence. It doesn't matter whether being able to do those sorts of things was learned, or evolved, or written as routines in a giant program, since to me intelligence is more about what things you can do rather than how you do it.
posted by burnmp3s at 2:14 PM on April 22, 2009


Primate intelligence represents a variant of this approach: complex, adaptive behaviors for modifying one's own environment with the goal of consistent access to high-density resource caches.

Ryvar: Well, if evolution in the case of primates is, as you suggest, working toward a "goal of consistent access to high-density resource caches" then it seems to be me evolutionary theory needs to be revised to incorporate additional mechanisms beyond natural selection and random mutation.

But I don't think it needs to be, because that's not what it's doing. By the numbers, natural selection vastly prefers dumb plants and bugs to smart animals. In fact, simple lifeforms outnumber more complex organisms and higher primates in such lopsided proportions there's no evidence whatsoever that the emergence of animal let alone human intelligence confers any significant adaptive benefit whatsoever.
posted by saulgoodman at 2:27 PM on April 22, 2009


hippybear: it's one of those links that lurks around your brain until someone posts something like this and you're like "damn, I've seen this before, google google, there we go!"
posted by oonh at 2:56 PM on April 22, 2009


Once you bring in choice you get into the whole free will argument that never goes anywhere

Unsurprisingly we're sliding back to the themes of this recent thread, but I'll have a go of it anyway.

I'm not sure where the "free will argument" is supposed to "go."

To me it's the most natural thing in the world to say I have some degree of free choice, and I don;t think it's an empirically suspect statement at all. Now one can counter, a la the Churchlands, that I am merely suffering from folk-psychological delusions implicit in the way we speak about such things as motivation and willing (or for that matter qualia like pain, but replacing the term "pain" with "neural c-firings" only begs the question of what is being described), but I don't think so. I do not have to posit a mysterious entity to say that I have some, albeit biologically constricted, degree of free choice. I am talking here about conceiving of freedom unsentimentally, and thoroughly within a bio-evolutionary framework--not unlike the way Dennett does in his book Freedom Evolves.

It's hard to define intelligence in ways other than describing what humans can do that other animals can't

I don't think so at all, and in fact I think we need to define intelligence within an animal context, since we are animals. But that does not mean that only external indications are meaningful, as a behaviorist approach might suggest. Rather, we have sufficient reason to carefully, and through psychological context (re: areas of research such as child development and linguistics), apply our own first person experience in order to frame the question of human intelligence. There is no reason to think we can't make some adequate first approximation of what constitutes human intelligence by both empirical and rational means. And to organize that definition according to our own status as primates.
posted by ornate insect at 3:36 PM on April 22, 2009


Must think of a reason to post.... must think of a reason to post.....

OK: for the response to the pulse of cold, I wouldn't assume intelligence, I'd look at cyclic-AMP.

There, I posted. Take that, Physarum. Cellular slime molds RULE.
posted by acrasis at 5:27 PM on April 22, 2009


Those photos on englishrussia are gorgeous.

And I'm pretty sure I sat in one of the yellow ones once. That, or someone barfed scrambled eggs all over this one tree stump. I'll keep believing it was slime mold.
posted by eritain at 6:34 PM on April 22, 2009


they're just exhibiting behaviour!
(in all its myriad forms :)

i'm pretty sure there's a connection now between quantum intelligence and slime molds now :P

cheers!
posted by kliuless at 6:54 PM on April 22, 2009


The maze functionality is a simple 'least volume' problem. If one had a liquid that, with electric stimulation, would reduce itself to least volume, you'd get the same result: all non-essential branches would be subsumed into the most direct line between the two endpoints.
posted by five fresh fish at 7:25 PM on April 22, 2009


Interview with a fungus
posted by homunculus at 11:41 PM on April 22, 2009


ornate insect Now one can counter, a la the Churchlands, that I am merely suffering from folk-psychological delusions implicit in the way we speak about such things as motivation and willing

Have you ever looked into studies on split brain patients? I can't say I understand their condition all that well, but I find fascinating some experiments where a patient is sent a message to one side of the brain which causes an action when presumably, the other half of their brain has no understanding of why

For instance:
In one experiment, for example, when the word walk was presented only to the right side of a patient’s brain, he got up and started walking. When he was asked why he did this, the left brain (where language is stored and where the word walk was not presented) quickly created a reason for the action: “I wanted to go get a Coke.”
Alternatively experiments where specific mouse neurons are stimulated, causing the animal to go left. I can't find the link, but I recall originally reading it and one researcher speculating what the mouse must be "thinking" as it runs in these circles, "go left, go left!"

I'm not sure I have a point with this comment, but things like this make me wonder how much of our perceived consciousness and free will is just illusory. Would perceiving your own deterministic sentience even make sense, or is there something tautological about it that makes us perceive ourselves as free beings?
posted by crayz at 7:20 AM on April 23, 2009


Would perceiving your own deterministic sentience even make sense[?]

I think so... I believe free will is an illusion, as I believe the universe is deterministic.** I think if we had the Grand Equation of the Universes, we could say who I'd be dating in 5 years and 4 days, what I'll have for lunch, what my blood pressure will be, etc.

Another way to put it is: If you had your life to live over again, beginning in the exact same circumstances, with no additional knowledge that you didn't have this time around... would you do anything differently? The answer, IMO, is no of course not.

But the thing is... we DON'T have the Grand Equation, we can't even predict the weather in broad terms a few weeks out, so even if the universe is actually deterministic, even if we don't really have free will, we might as well. The illusion is good enough that it's functionally identical to reality.

"Intelligence", "sentience", "life", etc. are human definitions, and I believe they are an artificial, flawed representation of reality. So to me the answer to the question, "Is the slime mold intelligent?" is "I dunno, you tell me what you mean by 'intelligent'!"

** And, really, even if the universe ISN'T strictly deterministic, even if it's partially random, that doesn't bolster the free will argument -- how can you have free will when it's fundamentally impossible to determine what will happen next?
posted by LordSludge at 10:35 AM on April 23, 2009


Would perceiving your own deterministic sentience even make sense, or is there something tautological about it that makes us perceive ourselves as free beings?

This is slightly off the topic of free-will and back to consciousness, but it's a closely related point.

It seems tautological to me that any fully unconscious life form, by logical necessity, would be oblivious to the fact that it's unconscious. Because for a thing to possess the self-reflective capability to become aware of itself as an unconscious entity presupposes a certain level of consciousness in the thing already, doesn't it?

In other words, if you were a completely unconscious life form, you'd be incapable of seeing it, because seeing it would require you to be conscious.
posted by saulgoodman at 10:52 AM on April 23, 2009


Slime molds are so close to being both plant and animal that it's like they can't make up their minds. And they're thinking now that maybe this is who's been running the earth all this time... these layabouts who can't commit... and if they make up their minds to be either plant or animal, they'll take us over *snaps* just like that.
posted by 1f2frfbf at 1:16 PM on April 23, 2009


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