8 ms·

With a few minutes of googling the only reference i can find says that Tardigrades have approximately 200 neurons in their brains [1] and their dry weight is on

• crehn 5y ago
  For contrast, ants have around a quarter million neurons.
  • jcims 5y ago
    We have mud dauber wasps around the house. I can't find a good reference for neuron count...the only one I see is for super tiny parasitic wasps which I can't imagine is accurate. Lets assume they are on the order of honey bees at 500k-1M neurons. This past fall I saw one on the ceiling of my front porch. It had a rear leg pinched between the soffit and the edge of a can light. It was pretty obviously struggling, pulling away with its remaining legs and every now and then buzzing its wings. It was interesting but kind of a dumb 'more powah' response that could be the result of a biological integrator of some form. I then saw one of the most remarkable things that I've personally witnessed in nature. Another wasp of the same type was randomly flying by, about 6" below the level of the ceiling and along a path that would have brought it no closer than a foot away from the stuck wasp. After flying past the stuck wasp, it took a hard right, circled around and landed near the stuck one. It then proceeded to walk up, grab the stuck ankle (?) of the other wasp and help it tug. They both worked on it for a few seconds, broke the first wasp free (not sure if the foot was still intact), then they both flew away in different directions. I can build a mental model of a biological automaton lacing together finely tuned feedback loops that cause it to 'act' in a way that supports itself. Extending that to a point where it appears to identify, empathize, re-plan, solve a physical problem then resume prior plan starts to stretch my ability to imagine without some kind of subjective consciousness backing it all.
    • est31 5y ago
      > I can't find a good reference for neuron count https://doi.org/10.1371/journal.pone.0059090 https://doi.org/10.1371/journal.pone.0059090 DNA labelling and analyses of confocal z-series reveal that the brain of Macrobiotus cf. harmsworthi contains ∼200 nuclei that are arranged in a bilaterally symmetric pattern (Figure 2D and Figure S1). Since some of these nuclei are likely to be from non-neuronal cell types, such as glia cells, the tardigrade brain might contain fewer than 200 neurons. Some more reading: Martin et al. "The nervous and visual systems of onychophorans and tardigrades: learning about arthropod evolution from their closest relatives": https://bib-pubdb1.desy.de/record/401705/files/Martin_et_al.pdf https://bib-pubdb1.desy.de/record/401705/files/Martin_et_al.... Mayer et al. "Selective neuronal staining in tardigrades and onychophorans provides insights into the evolution of segmental ganglia in panarthropods": https://doi.org/10.1186/1471-2148-13-230 https://doi.org/10.1186/1471-2148-13-230 Also note that tartigrades apparently have a constant number of cells throughout their life, so instead of increasing the cell count, they just increase cell size. The cells can have increased complexity anyways. All it really means that the nervous system has about 200 nuclei. Also don't forget that even single celled organisms are capable of the classical behaviours like hunting for food, running away from predators, forming colonies (e.g. bacteria), etc.
      • ad404b8a372f2b9 5y ago
        I'm pretty sure he was referring to the neuron count of the wasp.
        • est31 5y ago
          Oh right, good point.
    • semireg 5y ago
      I know next to nothing about a bug’s life, but interesting to consider distress signals being tuned into otherwise solitary creatures. For colony wasp/bee I could see why distress would bring help (bring more venom!) but solitary… maybe it was kin?
• robbedpeter 5y ago
  They seem to occasionally seek the company of other tardigrades, and hug. It could be purely mechanistic stimulus response behavior, but I'd like to think they're experiencing some sort of life, and that it's mostly a good one. That second YouTube video is great!
  • p1mrx 5y ago
    > They seem to occasionally seek the company of other tardigrades, and hug. I would assume that this feature is necessary for reproduction.
• jer0me 5y ago
  Though the ant example may be more interesting, humans have ~86 billion neurons.
• fleddr 5y ago
  I don't know the technical answer to your question but I do think that us humans have continuously underestimated the complexity and intelligence (in the broadest sense) of animals. First, we see them as emotionless objects. Then we acknowledge that some animals seem quite smart, such as dolphins, dogs, pigs and cows, and of course other primates. Then we discover that far more animals have complex systems to communicate by language, signs or color, have advanced courtship rituals and actual emotions, such as an elephant mourning. And still we keep getting it wrong. Recently it was discovered that tiny earth worms, considered some of the "dumbest" and most primitive life forms, show complex behavior and have actual learning ability. For example, they drag leaves into their underground "den" to feed on them and over time learn which way is the correct way to drag the leaf, as the other way would block the den. That's a stunning interaction for such a simple creature. Because it isn't a simple creature. Nothing is.
  • abletonlive 5y ago
    Define "we". Because the smartest people I know are the ones most likely to underestimate as you've described and look down upon people that anthropomorphize. Further, it seems to me that the smartest people I know fall prey to reductionism when it comes to the subject of intelligence or philosophy in general.
    • nefitty 5y ago
      It's convenient to clamp our understanding of reality. If I convince myself that cows are baser creatures, it makes it a lot easier to enjoy this juicy burger made from its child.
  • yyyk 5y ago
    " do think that us humans have continuously underestimated the complexity and intelligence of animals... First, we see them as emotionless objects." No premodern culture thought so. As far as I know, it's only from Descartes on that the opinion you note existed.
    • fleddr 5y ago
• snidane 5y ago
  200 neurons, yet still more AI complete than any concocted deep learning attempt with way more of so called "neurons".
  • hungryforcodes 5y ago
    A 'neuron' might be a kind of the biological equivalent to the CPU or microcontroller. So saying that the Tardigrade has 200 CPUs sounds pretty good, actually. If you build a drone for example with 200 CPUs, you'd expect it to be pretty capable I'd imagine, including some form of AI or machine learning. And it seems to me neurons by default are machine learning "CPU"s...
    • mburee 5y ago
      Really depends, doesn't it? 200x something like a attiny13 is still kind of useless in that regard
      • hungryforcodes 5y ago
        I've never tried to build a Tardigrade with 200 attiny's, so I'm not quite sure....ESP32s with 8MB of PSRAM on the other hand....would it be enough?
    • kaba0 5y ago
      Well, not really. They are neither nodes only in a ML algorithm but neither are they complete processors. They are somewhere in between where they can do some limited “signal processing” (eg. throttle signal frequency, negate it, and have some form of primitive memory even), but they are likely not Turing complex in themselves.
      • jcims 5y ago
        Just dumping this somewhere, pretty informative video on how neuronal signalling works. https://www.youtube.com/watch?v=ZKE8qK9UCrU https://www.youtube.com/watch?v=ZKE8qK9UCrU
• Razengan 5y ago
  What says our consciousness is not just a long form electro-chemical reaction of deeply nested feedback loops programmed into millions of base pairs?
  • nefitty 5y ago
    It is, and it's a very immersive and persistent illusion.
  • jcims 5y ago
    AFAIK that’s the only explanation we have any evidence for at this point. It’s easy for me to think there’s magic buried in the hundred billion neurons and hundred trillion synapses in the human brain. But in the case of tardigrades or wasps, it becomes much less obvious where the consciousness would ‘live’ with such limited real estate.
    • kaba0 5y ago
      A wasp is at least an order of magnitude more complex than a tardigrade though (maybe even two orders?), and flying require quite complex intelligence so I would not put some for of consciousness for wasps. Though I would believe that their “brains” are entirely different from mammal brains, because to be honest, some mammals are really really dumb (and for a long time they were believed to be only “biological robots”?).
  • Emma_Goldman 5y ago
    The basis for believing this is the inference that because the physical world insofar as we have knowledge of it obeys physicalist principles, so must the human mind. But we can't really claim to know based on our investigation of the mind itself. If we entertain theories of consciousness like dualism, monism or emergentism, it seems unlikely that we have the categories of understanding and analysis to decisively confirm or deny them.
• ddingus 5y ago
  Or they are a case for this idea of the universe itself being conscious and beings tap into that via neurological mechanisms we do not understand well. It may be a base level of complexity / capability is needed to tap into the "field of consciousness", which could explain bees, these things, and other seemingly too small living systems doing more than their apparent weight class would indicate is possible.
  • moralestapia 5y ago
    Do you have some resources you'd like to share around this? Would love to read about it.
    • ddingus 5y ago
      https://www.nbcnews.com/mach/science/universe-conscious-ncna772956 https://www.nbcnews.com/mach/science/universe-conscious-ncna... I have seen this idea pop up a few times and find it intriguing. I have read much better, but struggle to find links right now. That said, this backgrounder / brief type piece should point you to the rabbit hole. To me, in the most general sense, it's similar to the idea of the universe being cyclic, rather than having some definitive beginning and or end. It may just always be. In this context, consciousness may be an emergent artifact of how living systems function, or maybe it's a thing of it's own, or... Who knows? I don't, but I consider basic branches of thought like this important, if nothing else to stimulate possible lines of thought easily passed by otherwise.
      • moralestapia 5y ago
        Thank you, I always had some thoughts in this direction, but never read about it somewhere else (never put time into it). I definitely think there's a lot more beyond what we are able to sense or even grasp (if that's the appropriate word); in a similar fashion to these sort of Flatland examples, about how 2D beings are unable to grasp our 3D world, perhaps only slices of it at a time ... What if consciousness is (or lives in) some sort of different dimension that we only get a glimpse of. What if, on that higher dimension, consciousness behaves like matter, has a definite structure, etc... Ammazing stuff to think about.
• otabdeveloper4 5y ago
  The amoeba has zero neurons, and yet it can hunt prey and can reproduce sexually. Our understanding of intelligence is so laughably primitive that it is "not even wrong".
  • Joeri 5y ago
    Makes me think of the classic video of a white blood cell chasing a bacterium. You can sense the frantic desperation of the bacterium as it tries to get away from something monstrous that will inevitably swallow it whole. https://youtu.be/JnlULOjUhSQ https://youtu.be/JnlULOjUhSQ
    • maxbond 5y ago
      I love this video and I agree that we tend to make entirely arbitrary decisions about what is and is not intelligent, which is far more a reflection on our own preconceptions than the nature of intelligence, but I would note that bacteria have a completely different experience of their environment than we do of ours, and always have a bit of a frantic vibe to them. On their scale, they are moving through molasses while being buffeted by particles causing them to turn and spin; they are entirely incapable of moving in a straight line, and their motility is fundamentally random. So they always have a sort of vibrating, frenetic quality to them.
  • mjburgess 5y ago
    I think we're well aware that systems without intelligence can act as-if they have it. It is on this basis humans have been superstitiously imparting souls to any-old-thing for thousands of years.
    • otabdeveloper4 5y ago
      What makes you say that an amoeba doesn't have intelligence?
      • mjburgess 5y ago
        intelligence, if it is to mean anything, is a property of agents who act guided by explicit interior representations of their external environment
• visarga 5y ago
  > For me it also raises the question of whether they have any subjective experience approximating what we describe as consciousness, or if the entirety of their life is just a long form electro-chemical reaction of deeply nested feedback loops programmed into ~55 million base pairs. Maybe they are the same thing. Adapting to the environment in order to survive is also the role of consciousness and intelligence in humans. The struggle for life provides a learning framework for the brain, and an intrinsic space of values and emotion, but for each species is different depending on their ecological niche. I often see people musing about consciousness as something supernatural (a "hard problem" for science), but forgetting to consider the formative role of the environment and the tight coupling of consciousness with goals, which are attainable in the environment. So the macro is being overlooked for the micro. We can explain much by just looking at the environment-body interaction without the need to identify the pixie dust in the brain. I think consciousness is a process encompassing the interplay between the body and part of the environment, not just the brain. We can't find it in the brain or in the neural net alone, but we can find it in a game of goal maximization of a learning agent. That would include a tardigrade[1]. [1] Aversive conditioning in the tardigrade https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776688/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776688/
  • mildmotive 5y ago
    But that still doesn’t explain how we, or other living beings are able to see and feel things from our own perspective. It is genuinely a hard problem, especially if you try to understand it from a purely naturalistic pov.
    • visarga 5y ago
      You can try to explain it: - we form unsupervised representations for vision, hearing and the other senses (first person perceptions) - we have goals that paint any situation into good or bad, any action into useful or not (emotions associated to the relation between perceptions and goals) - we form memories and our experience is dependent on past actions (semantic, episodic and procedural memory) - our environment is full of other humans so we have to predict their behavior as well, and we get to see ourselves as we think they see us (the self) It suggests a lot about how we get to "see and feel things from our own perspective". We have actual brain circuits dedicated for that, and a supportive environment for cultivating them.
• pibechorro 5y ago
  Its safer to assume all life is conscious than the common assumption that we are somehow special in that regard.
  • hypertele-Xii 5y ago
    All life is conscious, but is all consciousness alive?
  • kaba0 5y ago
    Is a primitive bacterium in any way or shape conscious? I think that would be a way too generous usage of the word.
    • jcims 5y ago
      A bacterium is a single cell. The neurons in our brains are also single cells. If we think consciousness is in the brain, then isn't it also in the neurons? If its in the neurons, is it in a neuron?
      • kaba0 5y ago
        No? Emergent properties are a thing.
• eitland 5y ago
  I had a light bulb moment a few years ago when I saw a seagull come in with the wind, turn against it and land perfectly at the top of a pole. Since then everything AI is still impressive to me but it just doesn't feel very advanced. Within a skull smaller than my fist, these birds have routines for repowering, communication, duplicating themselves, attack and defense. That is advanced.
• Symmetry 5y ago
  Evolution is really very clever not just in the how our neurons control our bodies but also in how our physical forms make the motions we need to perform natural. As an extreme case, there's the famous video of a fish able to swim upstream despite being dead[1]. Working with robotic grasping professionally has made me acutely aware of how awesome my hands are and how much easier they make daily life compared to simpler alternatives. All of which is to say that we shouldn't think about the tardigrades locomotion just in terms of the neurons its using. [1]https://fyfluiddynamics.com/2018/07/when-i-was-a-child-my-father-would-take-me-trout/ https://fyfluiddynamics.com/2018/07/when-i-was-a-child-my-fa...