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Of the designs of species that have evolved, I am curious why a 360 degree rotation, like a joint that can spin, does not seem to have evolved, for example wheels or a propeller.

Like, is there some reason we would expect evolution to not be able to discover those forms, or does it mean that it didn't evolve because it never was that advantageous? Owls can rotate their heads very far but not over and over in one direction. It's hard to imagine that wheels or propellers would not give you an advantage considering cars, helicopters, etc.

I think it's a puzzle because I never thought there was any form that evolution could not produce, and it's hard to believe it could not evolve in a way that was advantageous. But I think the second option is the better of the two. Maybe rotational joints are structurally weak?

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    $\begingroup$ Does this answer your question? Why do some bad traits evolve, and good ones don't? $\endgroup$
    – acvill
    Jan 20, 2023 at 12:42
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    $\begingroup$ It's tough connecting a blood supply to something like a wheel or propeller- it would basically need to be dead. How do you connect muscles? $\endgroup$ Jan 20, 2023 at 13:01
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    $\begingroup$ Those are bad examples. Would you replace your legs with wheels? Cars are pretty useless without roads. Also, helicopters are really big for something that hovers. Look at how big hovering animals are compared to animals that can't hover: hummingbirds and insects. They guzzle fuel. You can't find that much food in nature to survive and even if you could you wouldn't be able to consume it fast enough. Hummingbirds drink sugar and barely eat fast enough to not starve to death. At the sizes flying animals exist at wings are more efficient. $\endgroup$
    – DKNguyen
    Jan 20, 2023 at 14:42
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    $\begingroup$ It has. Look up ATP synthase. Or flagella $\endgroup$ Jan 20, 2023 at 16:40

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Actually there are propeller like features called flagellum (3) evolved on many organisms like plants, animal sperms (4), bacteria (1) and flagellates (2). There are known only one macroscopic form of such features in bivalves and gastropods (5) but it is used for digestion not for locomotion.

One reason why we don't see it everywhere is thought to be evolutionary constraints which means that some feature might give very big advantage but the evolution to this final working "product" goes through "valley" where half developed feature is discarded by selection as less advantageous to competing features (6). In case of rotating features there are thought to be too many physiological and physical "valleys" like nutrient transfer, friction, power transmission (6,7,8).

Second big reason is using wheel on terrain has many disadvantages like bad maneuverability and going over obstacles (7). Propellers in water have efficiency up to 60% and in air 80% but fish tails and bird wings are in range of 96-98% (9). Also there are known that even in human civilizations like in Mexico have discarded wheel as way for locomotion (10).

References.

  1. Bardy SL, Ng SY, Jarrell KF (February 2003). "Prokaryotic motility structures". Microbiology. 149 (Pt 2): 295–304. doi:10.1099/mic.0.25948-0. PMID 12624192.
  2. Silflow CD, Lefebvre PA (December 2001). "Assembly and motility of eukaryotic cilia and flagella. Lessons from Chlamydomonas reinhardtii". Plant Physiology. 127 (4): 1500–7. doi:10.1104/pp.010807. PMC 1540183. PMID 11743094.
  3. Jarrell K, ed. (2009). Pili and Flagella: Current Research and Future Trends. Caister Academic Press. ISBN 978-1-904455-48-6.
  4. Malo AF, Gomendio M, Garde J, Lang-Lenton B, Soler AJ, Roldan ER (June 2006). "Sperm design and sperm function". Biology Letters. 2 (2): 246–9. doi:10.1098/rsbl.2006.0449. PMC 1618917.
  5. Owen, Jennifer (1980). "Filter-feeding". Feeding Strategy. University of Chicago Press. p. 89. ISBN 978-0-226-64186-7.
  6. Gould, Stephen Jay (1981). "Kingdoms Without Wheels". Natural History. 90 (3): 42–48. ISSN 0028-0712.
  7. LaBarbera, Michael (March 1983). "Why the Wheels Won't Go". The American Naturalist. 121 (3): 395–408. doi:10.1086/284068. JSTOR 2461157. S2CID 84618349.
  8. Dawkins, Richard (November 24, 1996). "Why Don't Animals Have Wheels?". Sunday Times. Archived from the original on February 21, 2007.
  9. Diamond, Jared (April 14, 1983). "The Biology of the Wheel". Nature. 302 (5909): 572–573.
  10. Gambino, Megan (June 17, 2009). "A Salute to the Wheel". Smithsonian. Archived from the original on June 26, 2017.
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  • $\begingroup$ Another problem is both parts need to be made of living tissue, which means it needs to have a blood/nerve supply, but can't have any connection or it wont be able oto rotate. $\endgroup$
    – John
    Jan 21, 2023 at 1:01
  • $\begingroup$ @John - "Nutrient transfer" covers blood. The nerves involved in locomotion are mostly proximal and end at the neuromuscular junction. Of course pain and proprioception are important, too, pain as a warning and proprioception for the cooperation of the whole, but... could they be done away with for specific joints? Probably part of what the OP was asking. $\endgroup$ Jan 21, 2023 at 3:55
  • $\begingroup$ blood without blood vessels only works if the wheels are very small. diffusion scaleing the bane of weird biology. $\endgroup$
    – John
    Jan 21, 2023 at 23:06
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This very question has been asked a number of times before. Maybe an answer to why this is not superior to legs (or any other appendage) is in order.

Your head, arms and legs don't move through magic. They move because they are attached to other bones by ligaments, muscles and tendons. There are ligaments surrounding each joint holding it in place, and blood vessels feed these living tissues as well as the bones themselves. When joints are forced beyond their anatomical limits, ligaments tear, tendons tear or snap, sometimes muscles tear, and blood vessels rupture. (That's why even a mild ankle sprain results in swelling.)

The closest thing to full rotation of the arms is found in gibbons (picture these animals gracefully swinging through trees.) The range of motion of their arms is amazing, and occurs due to elongated tendons, significantly different shoulder bony anatomy, and greater forelimb muscle strength. But it is not, cannot, and will never be 360 degrees, nor is there a need for it: they simply change hands to achieve their forward movement. If they need to change directions (go back) they pivot/turn around, not swing backwards.

An owl's head can rotate an astounding 270 degrees in either direction. Deceased owls were studied at Johns Hopkins to determine how they can do so without keeling over.

If humans attempted to turn their heads as quickly or as far as owls do, artery linings would tear, causing blood clots to form and potentially leading to a stroke not to mention broken necks, explained study author Dr. Philippe Gailloud in a statement.

To understand the details, read the link. It's short and of interest. Still, it's not 360 degrees. This is true for any joint in the body.

Why? Because it's physiologically impossible. Full rotation would tear apart the very things necessary for any motion at all in living animals. So no wheels or propellers, please. At the very first 360° rotation, the joint would be rendered nonfunctional, which would very likely result in a much earlier death.

People with Ehlers-Danlos Syndrome have stretchier ligaments allowing more extremes of motion, but that comes with its own problems. So it's not "better".

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