On Nov. 11, 1954, Syuiti Mori turned out the lights on a small group of fruit flies. More than 60 years later, the descendants of those flies have adapted to life without light. These flies — a variety known as ‘Dark-fly’ — outcompete their light-loving cousins when they live together in constant darkness, according to new research. Re-playing the evolution of Dark-fly identified the genomic regions that contribute to its success in the dark.