Professor Malcolm Burrows, of the Cambridge Department of Zoology, has described a pair of naturally evolved gears in nymphs of the leafhopper genus Issus. Unfortunately the actual paper’s been paywalled by Science magazine but there’s a ton of coverage on the intarwebs.
“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,” added co-author Gregory Sutton, now at the University of Bristol.
“These gears are not designed; they are evolved – representing high speed and precision machinery evolved for synchronisation in the animal world.”
Interestingly, the mechanistic gears are only found in the insect’s juvenile – or ‘nymph’ – stages, and are lost in the final transition to adulthood.
Adult leafhoppers have fully developed nervous systems and elytra that let them control their hopping to an incredibly fine degree. The gear structure found in the nymphs is believed to have evolved so that they can make powerful straight-line jumps before they are fully mature. Burrows and Sutton point out that while a geared system is not particularly fault-tolerant – losing any single gear tooth is crippling – such damage can be repaired by nymphs as they transition to their the next instar.
Cambridge has a Natural History Museum, so it must be a great place for a zoologist to work.