Abstract
More than 20 years before DNA was identified as the hereditary material, the Drosophila geneticist, Hermann Muller, envisioned the fundamental principles that such a molecule must have: to be auto-assembling and to be mutable but then again stable. He followed his prescient review of these properties with a remarkable prediction: learning about the hereditary material and its properties would not come from studying Drosophila, but from studying bacteria and their bacteriophages.