Bacteria hold a record of how their environment affects them, a new study suggests, and this can be passed on to subsequent generations when they divide. The discovery is one among many in recent years that have complicated the ways biologists think about evolution and the transmission of characteristics. It could also have important medical applications, for example in tackling antibiotic resistance. Once Darwin’s theory of natural selection, combined with Gregor Mendel’s evidence for dominant and recessive genes, had swept creationist ideas to the fringes, attributing everything to genes bec…