Researchers have recently discovered what looks like mechanical gears on the tiny hopping insect, Issus coleoptratus. While other examples of mechanical gear-like structures have been found on other animals, they have proved to be simply ornamental. The structure found on the Issus, however, actually functions like our geared systems. The juvenile Issus has gears located at the top of their hind legs, which help them with coordination. The gears help the insect jump forward by synchronizing their back legs. The back legs are locked together, allowing both legs to rotate at the exact same time, which causes the insect to jump forward. Because both legs swing laterally, if either one was not in perfect sync, it could cause the insect to move off course to the right or left. This simple gearing system allows the Issus to cock their legs backward and then simply push forward without them needing to perfectly synchronize their movements.
The researchers were able to prove this by electrically stimulating the legs of a dead Issus after they manually cocked the legs backward. The insect jumped forward without the researchers needing to coordinate its legs. The teeth in the gears even have filleted curves, something scientists had previously thought was only present in human-made mechanical gears. These insects appear to have discovered mechanical gears way ahead of humans.
Have you ever looked at an insect and marveled at their intricate structure? How did something this sophisticated form on such an unsophisticated creature?