Issus, a plant-hopping insect found in gardens across Europe, possesses hind-leg joints with curved cog-like strips of opposing teeth that intermesh, rotating like mechanical gears to synchronize the animal's legs when it launches into a jump, researchers at Cambridge University reported Thursday.
Calling it the "first observation of mechanical gearing in a biological structure," the scientists said the discovery shows gear mechanisms previously thought to be solely man-made have an evolutionary precedent.
The gears in the Issus hind-leg bear remarkable engineering resemblance to those found on bicycles and inside car transmissions, they said.
The help coordinate the powerful jumps that are this insect's primary mode of transport, they said, because even tiny discrepancies in synchronization between the jumping action of its legs would result in "yaw rotation," causing the insect to spin hopelessly out of control.
"This precise synchronization would be impossible to achieve through a nervous system, as neural impulses would take far too long for the extraordinarily tight coordination required," Cambridge zoologist Malcolm Burrows said.
With the biological gears the legs interlock creating absolute synchronicity in the jumps, the researchers said.
"We usually think of gears as something that we see in human designed machinery, but we've found that that is only because we didn't look hard enough," study co-author Gregory Sutton at the University of Bristol said.
"These gears are not designed; they are evolved -- representing high speed and precision machinery evolved for synchronization in the animal world."