[_Stefan_]

Are there wheels in nature? Or are humans the first to invent/develop them?

[another_someone]

How do you define a wheel?

There are ball and socket joints which are capable of rotation, but are prohibited from continues rotation by the attached muscles.

There are things in the natural world that do continuously rotate.

The big invention for humans was not really the wheel, but the axle (i.e. a way of harnessing a continuously rotating object to a stationary object - although nature does use axles for components that can rotate in a non-continuos manner).

[JimBob]

There are some lizards that bite their tail and roll down-hill when threatened. They are in a sort of circle so they may be considered a wheel. Any other examples, people?

[lightarrow]

Are there wheels in nature? Or are humans the first to invent/develop them?

What about Saturn's rings?

[Soul Surfer]

Nature could not "invent" the wheel because of the severe problems of ensuring a blood and nervous supply to a rotating object that can perform an undefined number of turns in the same direction the best you can get are ball and socket joints like hips and eyeballs.

[Carol-A]

If you look at the structure of the ATPase,(mitochondria and chloroplasts) it is a rotating wheel on a "shaft", that rotates in 1 direction for a long time... []

[RD]

There are some lizards that bite their tail and roll down-hill when threatened.
 They are in a sort of circle so they may be considered a wheel.
 Any other examples, people?

What about Tumbleweed ?