3 ms·

I wonder if it’s possible for a creature to have axles and some kind of differential?

by xwdv 6y ago

tootie 6y ago
This is video is really aimed at kids but gives some good explanation of why it's likely impossible: https://youtu.be/YkS1U5lfSRw https://youtu.be/YkS1U5lfSRw The "gears" on this insect are basically intersecting teeth on two otherwise normal leg parts. Evolving an axle or any other free spinning part would require disconnected parts. The external parts would be cut off from any metabolic functions of the main body. Nothing remotely like that has ever evolved before so it would be nigh impossible.
- Conlectus 6y ago
  It seems to me this "impossibility" might be an artifact of definition: if some system contains disjoint parts, we no longer call it "an animal". Colonial animals are the edge case here. Most would be hesitant to say an ant colony is "an animal", but are happy to refer to a Portuguese Man 'o' War as such, despite also being a colony.
  - curryst 6y ago
    All members of a colonial animal are genetically identical, which I believe is why a man of war is an animal but an ant colony is a society. I don't think ants are genetically identical, although I'm not certain. Man o Wars are also not disjoint. They have specialized cells, but I believe share nutrition among the non-feeding cells. A truly disjoint creature would need a metabolic system on both sides of the disjoint, a separate nervous system, and perhaps most difficult, a way to pass messages across the disjoint quickly enough to be useful (aka electric impulse). At a certain point, I think it starts becoming dubious whether it's a single creature. Even if they're genetically identical, they start to look more like twins than a colonial creature.
    - throwanem 6y ago
      Workers in a given ant colony - really, daughters of the same mother in any hymenopteran species, all of which use haplodiploid sex determination - are more closely related than siblings in species with fully diploid sex-determination systems, but they're not clones.
- Tossito190 6y ago
  Human teeth, hair. There's plenty of possibilities there. Especially with keratin. Nails are plenty robust. The real question is how do you motivate those disconnected components to perform work efficiently, but with gears like those in the OP you could hypothetically build a ratcheting system.

I wonder if it’s possible for a creature to have axles and some kind of differential?

by xwdv 6y ago

I wonder if it’s possible for a creature to have axles and some kind of differential?

This is video is really aimed at kids but gives some good explanation of why it's likely impossible: https://youtu.be/YkS1U5lfSRw https://youtu.be/YkS1U5lfSRw The "gears" on this insect are basically intersecting teeth on two otherwise normal leg parts. Evolving an axle or any other free spinning part would require disconnected parts. The external parts would be cut off from any metabolic functions of the main body. Nothing remotely like that has ever evolved before so it would be nigh impossible.

Conlectus 6y ago
It seems to me this "impossibility" might be an artifact of definition: if some system contains disjoint parts, we no longer call it "an animal". Colonial animals are the edge case here. Most would be hesitant to say an ant colony is "an animal", but are happy to refer to a Portuguese Man 'o' War as such, despite also being a colony.
- curryst 6y ago
  All members of a colonial animal are genetically identical, which I believe is why a man of war is an animal but an ant colony is a society. I don't think ants are genetically identical, although I'm not certain. Man o Wars are also not disjoint. They have specialized cells, but I believe share nutrition among the non-feeding cells. A truly disjoint creature would need a metabolic system on both sides of the disjoint, a separate nervous system, and perhaps most difficult, a way to pass messages across the disjoint quickly enough to be useful (aka electric impulse). At a certain point, I think it starts becoming dubious whether it's a single creature. Even if they're genetically identical, they start to look more like twins than a colonial creature.
  - throwanem 6y ago
    Workers in a given ant colony - really, daughters of the same mother in any hymenopteran species, all of which use haplodiploid sex determination - are more closely related than siblings in species with fully diploid sex-determination systems, but they're not clones.
Tossito190 6y ago
Human teeth, hair. There's plenty of possibilities there. Especially with keratin. Nails are plenty robust. The real question is how do you motivate those disconnected components to perform work efficiently, but with gears like those in the OP you could hypothetically build a ratcheting system.