Previously believed to be only man-made, a natural example of a functioning gear mechanism has been discovered in a common insect - showing that evolution developed interlocking cogs long before we did. The juvenile Issus - a plant-hopping insect found in gardens across Europe - has hind-leg joints with curved cog-like strips of opposing ‘teeth’ that intermesh, rotating like mechanical gears to sy
![Functioning ‘mechanical gears’ seen in nature for the first time](https://cdn-ak-scissors.b.st-hatena.com/image/square/014587276c6024ea487ea18bb8ae56fb96a9e3f4/height=288;version=1;width=512/https%3A%2F%2Fwww.cam.ac.uk%2Fsites%2Fwww.cam.ac.uk%2Ffiles%2Fnews%2Fresearch%2Fnews%2Fgears-2.jpg)