Mechanical Gears have long been thought to be solely a
product of human ingenuity. That view has been proved wrong! Interlocking gears
have been discovered in a living creature—the juvenile Issus leafhopper,
found in gardens all over Europe.
A
juvenile leafhopper can reach a velocity of 3.9 meters per second in just two
thousandths of a second, subjecting its body to nearly 200 times the force of
gravity! It can disappear from sight during the blink of an eye. Such leaps
require that both of the creature’s two hind legs exert exactly the same force
at precisely the same time. What is the secret behind this precision?
Scientists have discovered two interlocking gears at the base of the leafhopper’s two hind legs. When the insect leaps, those gears ensure that both legs are perfectly synchronized. Otherwise, a leap would become an uncontrolled spin!
When jumping, larger creatures rely on their nervous system to synchronize their legs. For the juvenile leafhopper, however, neural impulses would be too slow. Hence its two interlocking gears. “We usually think of gears as something that we see in human designed machinery,” says researcher Gregory Sutton. The reason, he adds, is that “we didn’t look [elsewhere] hard enough.”
