Tardigrades walk like insects 500k times their size
arstechnica.com
arstechnica.com
>Thus, miniaturisation of the tardigrade nervous system is achieved largely by reducing cell numbers, neuropil branches and the number of synaptic connections, while, at the same time, increasing functional specificity. Nonetheless, given the proximity of synaptic neighbours, these adaptations are unlikely to compromise functionality to any great degree.
Now go to YouTube and search for videos of tardigrades operating in their environment. Here are a few examples:
I'm blown away by the complexity of their interaction with the environment and the stark simplicity of their neurological wiring relative to anything else that I can think of. 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.
Either way it’s simultaneously amazing and humbling.
1 - https://bib-pubdb1.desy.de/record/401705/files/Martin_et_al....
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.
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.
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....
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
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.
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!
I would assume that this feature is necessary for reproduction.
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.
No premodern culture thought so. As far as I know, it's only from Descartes on that the opinion you note existed.
Another pivotal moment would be have to be the invention of agriculture, some 10K years ago. Only from this point on begins the idea of animals as property.
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...
Anyways my statement was analogical -- and as we know analogies are merely tools for extending thinking from one paradigm to another. Best not to take it TOO literally.
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.
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.
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.
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.
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.
Have fun.
And for a fun magazine read: https://www.noemamag.com/the-conscious-universe/
Given that state of affairs, I find it useful to be aware of the various major, core ideas. Anything could lead us to some greater understanding.
It is a fun idea to think about, like a field of sorts that can be tapped into.
For all we know there are new physics out there.
The other idea that I find compelling, and this is my own idea, is get consciousness of some kind the organism or mechanism must be complex enough to differentiate itself very fully from the world around it.
We may end up making a smart brain in the box, but I don't think it will become conscious, unless it is complex enough to be aware of itself completely. And I'm sorry I'm having a hard time articulating this this morning, but just think about your fingertip we've got nerves and everything going all the way down there so that the whole mechanism is a closed loop it's kind of like we're built to know what is us what is not us completely with high fidelity.
I think we're going to find that is a requirement for a self to manifest or in some way defines a being from a mechanism.
Mechanisms will not be conscious, beings will.
In any case we're pretty ignorant right now, meaning that Consciousness is Magic, and we can talk about all sorts of stuff and not be out of bounds.
There is no reason to believe...
I'm not sure what context you were speaking in, but I have a fairly conservative frame I work with, and that is we know almost nothing. The scientific method does bring us understanding and that's basically a monkey see, monkey do kind of thing where we understand doing a is going to yield b.
Understanding is predictive to a point, and at that point, error exceeds understanding for whatever reason, and we simply don't understand enough to proceed, which drives new science and ultimately, new and improved understanding.
None of that actually invalidates prior understanding. Where understanding is predictive, and it has been validated against the authority; namely, mother nature, it's good understanding! And that all means knowing the limits of understanding is as important as the understanding itself is. Applying our understanding outside it's scope can be worse than ignorance.
Perhaps this is all well trodden ground for you, and I apologize in advance, but it did also highlight "reason to believe", and I just generally don't. For me, there just isn't a lot of room for "believe" in all this. Knowing things is a tall order. Confidence in understanding may just be a technical, formal expression of believing too.
Where we lack understanding, it's a guessing game. We may make pretty good guesses, depending on what understanding we do have and our own nature, intuition and such, and that's fine, even ideal depending on what the scenario is.
Maybe I would go down this road saying something more like, "I suspect" or "these ideas are suggestive", hinting at whatever basis I might have to give an idea greater weight or worth, but indeed! There is no reason to believe anything is true about the universe on basic principle, knowing our current limits and how we arrive at pretty much anything useful.
Later, below you used "unlikely" which suggests to me we get after thoughts like this in a similar way, and it's OK if not, but somehow I felt compelled to just get these reasoning basics out there, out of my head.
Happy New Year, and thanks in advance for entertaining me.
Our understanding of intelligence is so laughably primitive that it is "not even wrong".
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.
I would be very hard to do what they do without one.
The question is whether the system is able to perform any explicit inference with those representations. Ie., is the representation explicit available, as a representation, eg., that this representation can be employed to imagine the world being a different way (the heart of solving problems using intelligence).
It's worthwhile distinguishing a certain pun on the word "intelligence". We don't call gangster's intelligent, and physicists dumb -- despite gangster's being much more adept at most "physical skills". The esteem for "intelligence" comes from its association with The Intellect (ie., cognition and imaginative simulation, the place of explicit representation). Not from adept procreation, at which the cornavirus is presumably then almost "the most intelligent lifeform".
An amoeba doesnt represent the world to itself. It's an interesting biochemical system which interacts with its environment in a way which seems as-if intelligent. Digital computers likewise seem as-if intelligent. Ie., they seem as-if they explicitly represent the world to themselves -- but they dont.
Many things seem to be doing what we do, many things which dont, can (ie., we can automate some problem solving so that it doesnt need intelligence). But this is only seeming. These systems are nothing like us at all, they are radically alien -- they're, in any sympathetic sense, dead. There is "nothing that they are doing" -- there's no "they" there.
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/
- 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.
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.
[1]https://fyfluiddynamics.com/2018/07/when-i-was-a-child-my-fa...
Tardigrades Walk - https://news.ycombinator.com/item?id=28380188 - Sept 2021 (29 comments)
Entanglement between superconducting qubits and a tardigrade - https://news.ycombinator.com/item?id=29580686 - Dec 2021 (111 comments)
So they expected them to walk like horses and not insects? That seems odd.
cockroaches, for instance, only use their back 4 legs when 'running', and will use only their back 2 legs when all out 'sprinting'. we humans start jogging and then running as speed increases for the same reason, it's not energetically efficient to just 'walk faster'.
> the size of tardigrades (which are only about 0.02 inches long)
> the creature's movement resembles that of insects 500,000 times their size
0.02 inches x 500,000 = 10,000 inches or 833 feet. Where does one find insects 800+ feet long? Or rather, how does one stay the heck away from them?
Can tardigrades really "see" in the traditional sense? Can they make out shapes, etc.? Do they have photo receptors plugged into the brain?
It's amazing what those little creatures are going through since we discovered them.