While humans are no stranger to biomimicry - the practice of engineering items based on forms found in nature - it is less common to discover things in nature that were thought to be human invention. Some insects look like living machinery, as their joints look less like the product of evolution and more like something manufactured by man.
Recently it was discovered that the issus, a small planthopping insect, has a biological gear. This is the first time anyone has discovered a natural gear and has been the obvious cause of much excitement. The issus is only 2 mm long and when it jumps it reaches forces of 400 g's, which is about 20 times the maximum a human can endure.
It is thought that the gear exists to make sure that both legs are jumping at the same rate which allows the insect to better aim the jump. This would give considerable advantage when trying to evade predators like birds, parasitizing wasps, or larger animals that might eat it on accident while ingesting the plant. However, this amazing adaptation is not without its drawbacks. In order to work correctly, the teeth must be in good condition. If the insect is injured and the teeth on the gear become damaged, the issus will not be able to move well, if at all. This might be the reason that gears for synchronizing leg movement is not more common, as it has the potential to become quite costly.
Gears were invented by humans over 2000 years ago in ancient Chinese civilizations, but there was nothing known in nature to have given that inspiration.
The weevil is another insect that has amazing machinery-like joints. Instead of gears, the weevil’s legs attach to the body via a screw joint. The trochanter at the top of the insect’s femur is shaped like a screw and attaches to the coxa (similar to the hips on a human) which highly resembles a nut. As weevils spend a considerable amount of time climbing, this affords it a greater range of motion.
As time goes on, it may become more evident that while humans have some fantastic ideas, we are just catching up to ideas that evolution figured out a long time ago.