“O morning, as Gregor Samsa was waking up from anxious dreams, he discovered that in his bed he had been changed into a monstrous verminous bug,” wrote Franz Kafka in The Metamorphosis. “He lay on his armorhard back and saw, as he lifted his head up a little, his brown, arched abdomen divided up into rigid bow-like sections. From this height the blanket, just about ready to slide off completely...

The order of discovery can have a profound effect upon the way in which we think about the function of a gene. In E. coli, recA is nearly essential for cell survival in the presence of DNA damage. However, recA was originally identified, as a gene required to obtain recombinant DNA molecules in conjugating bacteria. As a result, it has been frequently assumed that recA promotes the survival of ...