Why Don't Any Animals Have Wheels?
Why Worldbuilding Stack Exchange recommends it
Worldbuilding Stack Exchange users link it when a question involves wheeled or rolling creatures or organic vehicles, since it explains why such biology is so unlikely.
Recommended by 1 people across 1 different months, 2015 to 2019.
What it is
A short Vsauce explainer on why no animal has evolved wheels, covering the biological obstacles such as blood and nerve supply across a rotating joint. It also touches on rotating structures like the bacterial flagellum and the history of human wheel use, and is hosted by Michael Stevens.
What people said
Recommends Ben Hollier · 2015-04 · Worldbuilding Stack Exchange · on “Sea creature moving via rotational motions”
There is a good vsauce video [this video] on why land animals don't have wheels, and I think it deals with the same issues
Cites ATaco · 2017-07 · Worldbuilding Stack Exchange · on “Could a species evolve a special organ that stores pure energy & allows it to control its own magnetic field?”
Storing Energy Surprisingly, most creatures already do this! Fats built up on the body contain Chemical potential energy [LINK] , as does glucose molecules in cells. This definitely isn't storing lightning in your veins, but organic flesh isn't very good with electricity as we know it. Fat itself contains around 9 calories per gram, which is about 37kJ of raw energy waiting to happen. 1 kilo of fat contains 37,656 kilojoules of energy. This is actually rather impressive, compared to our modern batteries, which usually contain around 360 - 900 kj/kg, human fat is a lot better at storing energy than a literal battery in your chest. Comparison of Energy Densities [LINK] Storing "Pure" Energy En
Cites Philipp · 2019-03 · Worldbuilding Stack Exchange · on “Would it be possible to create a vehicle completely from organic material?”
Training an animal to carry you around is called "riding" and an animal trained to carry stuff for you is called a "pack animal". Humanity is very successful at training animals that way for millennia, long before the discovery of neurosurgery. If you are thinking of an animal with wheels, well, that's more complicated than you think [this video] . A wheeled vehicle can only work when there is no permanent connection between the axle and the body of the vehicle. But with biotechnology that's difficult, because you can hardly have a circulatory system that way. The body of the vehicle and the wheels would need to be independent creatures. And this form of co-dependent evolution is very unlikely.