Butterflies on a south pacific island are teaching scientists new things about evolution.
The Blue Moon butterfly population on the island had been devastated by a bacterial parasite - in 2001, males of the species made up just 1% of the specimens studied. A gene protecting against the bacteria was developed naturally by the species, and as of 2006 the male population was back up to 40%.
Scientists are astonished at the speed of the organism’s response – rather than thousands of years, the change came about in only 5.