Trudy Mackay with Magnify Flies (IMAGE) Clemson University Caption Trudy Mackay uses the fruit fly (Drosophila) as a model system because more than 70 percent of disease-causing genes in humans have a fly counterpart and researchers can precisely control the genetic background and environment of the flies. Credit Clemson University College of Science 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.