Nature creates round objects all the time (stones in a river, a hedgehog in a ball,…), but the principle of an axle is not found as far as I know.
Nature creates round objects all the time (stones in a river, a hedgehog in a ball,…), but the principle of an axle is not found as far as I know.
But good sir, what use is an axle and wheel without whatever doohicky thingamajig that attaches to a frame that transports things or people?
Not sure if you’re serious or not, but wheels and axles are used for a lot more than just transportation. Pottery wheels predate vehicles by about 1,000 years. Windmills and water wheels use interlocking wheels and axles to grind grain. A windlass is essentially just a rope tied to a wheel on an axel for hoisting stuff up, like a bucket in a well.
Not that this matters to the discussion of naturally occurring wheel-and-axle structures. Just an interesting little aside on the value and versatility of wheels.