Fruit Flies (IMAGE) University of Veterinary Medicine -- Vienna Caption In fruit flies, many genes can contribute to adaptation, but only some of them are actually being used. Credit ©PopGen/Vetmeduni Vienna) Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.