Tardigrades walk like insects 500k times their size
arstechnica.com
Tardigrades walk like insects 500k times their size
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Re: Tardigrades walk like insects 500k times their size
#2Recent and related:
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)
Re: Tardigrades walk like insects 500k times their size
#3Recent and related: 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)
Thank you for linking those threads as the latter one was a thrill to read: both the thread as the paper.
Re: Tardigrades walk like insects 500k times their size
#4“The team was surprised to note that the water bears did not have distinct gaits for each speed, like horses as they transition from a walk to a gallop. Rather, their locomotion closely resembled that of insects and arthropods, scurrying along faster and faster with no change to the basic step pattern.”
So they expected them to walk like horses and not insects? That seems odd.
Re: Tardigrades walk like insects 500k times their size
#5This has been known for a while now, but it's definitely still fascinating.Also it reminds me of another similar comparison: humans "walk" like proteins on microtubes.
Re: Tardigrades walk like insects 500k times their size
#6> "Other times, they’d see something they like and run towards it.”
Can tardigrades really "see" in the traditional sense? Can they make out shapes, etc.? Do they have photo receptors plugged into the brain?
Re: Tardigrades walk like insects 500k times their size
#7With 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 the order of one microgram [2]. They also have a lower count of synaptic connections (from the same paper):
>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....
Re: Tardigrades walk like insects 500k times their size
#8> "Other times, they’d see something they like and run towards it.” Can tardigrades really "see" in the traditional sense? Can they make out shapes, etc.? Do they have photo receptors plugged into the brain?
They can't "really see"... they have eyespots with just a handful of light-sensitive cells and no lenses, so it's just gradients of light and dark. But they have other senses and I think the word "see" was metaphorical here, meaning they sensed the presence of an attractive stimulus. In some ways the real meaning of "see" doesn't depend on optics, you see?
Re: Tardigrades walk like insects 500k times their size
#9With 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 the order of one microgram [2]. They also have a lower count of synaptic connections (from the same paper): >Thus, miniaturisation of the tardigrade nervous system is achieved largely by reducing cell numbers, neuropil branches and the number of synaptic conn…
For contrast, ants have around a quarter million neurons.
Re: Tardigrades walk like insects 500k times their size
#10With 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 the order of one microgram [2]. They also have a lower count of synaptic connections (from the same paper): >Thus, miniaturisation of the tardigrade nervous system is achieved largely by reducing cell numbers, neuropil branches and the number of synaptic conn…
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!