In the realm of the minuscule, where creatures often escape human scrutiny, a remarkable discovery has unfolded. Unveiling a mere three millimeters in size, these inconspicuous insects hold a secret that challenges conventional understanding.
Upon closer inspection with magnification, particularly focusing on the intermediate region between their hind legs, one beholds nature's most peculiar innovation.
You're not mistaken (see image below)!
These tiny creatures have evolved gears, making them the only known species to possess and utilize gear-like structures in their biology.
Around 300 BC, Greek mechanics pioneered the invention of mechanical gears, laying the foundation for centuries of technological advancement. What was once a humble invention has since become integral to various mechanical systems.
Before the discovery of a certain tiny creature, the notion of gears evolving in nature seemed implausible. However, nature has a knack for defying expectations, as demonstrated by the astonishing creativity of living organisms.
Enter Issus coleoptratus, commonly known as the issus or the froghopper. These minuscule critters have a remarkable need for gears due to their prowess as extraordinary jumpers. Despite their diminutive size, they can execute leaps between two branches, reaching accelerations of 500-700g during takeoff.
In such high-stakes jumps, precision is paramount. Even the slightest discrepancy in the force exerted by their two hind legs can lead to mid-air spinning or veering off course, rather than landing precisely where they intend.
On the flip side, the two legs they power are positioned beneath their bodies, which makes them less tolerant of errors in propulsion compared to insects with legs around their bodies.
In fact, the margin for error in neural control of leg propulsion has surpassed the limit of error that a froghopper can tolerate during its jumps.
So, they've devised a gear-like solution, substituting their skeletal structure for neural control, reducing propulsion errors since the mechanical engagement of gears ensures both legs are activated simultaneously.
However, adult froghoppers lack gears; the final molt of a nymph removes them, potentially linking their absence to the inability to repair skeletal damage once gears wear out, as adults don't continue molting to mend their skeletons.
