WHY INSECTS GAVE UP FLIGHT
Most insects can fly, yet scores of species have lost that extraordinary ability, particularly on islands. On the small islands that lie halfway between Antarctica and continents like Australia, almost all the insects are no longer able to become airborne, with the result that flies walk and moths crawl.
“Charles Darwin recognised this wing loss characteristic, which is a particular feature of island insects,” says Rachel Leihy, from the Monash University School of Biological Sciences in Australia. “He and the famous botanist Joseph Hooker had a substantial argument about why this happens. Darwin’s position was deceptively simple. If you fly, you get blown out to sea. Those left on land to produce the next generation are those most reluctant to fly, and eventually evolution does the rest.”