The fascinating compound eyes of insects consist of hundreds of individual eyes known as "facets". In the course of evolution, an enormous variety of eye sizes and shapes has emerged, often representing adaptations to different environmental conditions. Scientists, led by an Emmy Noether research group at the University of Göttingen, together with scientists from the Andalusian Centre for Developmental Biology (CABD) in Seville, have now shown that these differences can be caused by very different changes in the genome of fruit flies. The study was published in the journal Molecular Biology and Evolution.