The discovery that there are bacteria in mucus in the human nose that secrete an antibiotic that kills other, more dangerous, forms of Staphylococcus before they can kill us, illustrates some important truths of science. The first is that properly trained minds can make the study of almost anything, however unlikely, rewarding. Microbiota turn out to be a playground for the enquiring mind. If the new substance is proved to work in humans as it does in mice, it may save thousands of lives a year from MRSA infections. The second is that, from the discovery of antibiotics to the methods of gene sequencing and now gene editing, modern medicine often depends on co-opting to our purposes tricks that nature has already found. The human ingenuity consists in recognising the prior ingenuity of evolution. Science has often appeared to depend on chance, although what looks like chance may be more to do with the scientific mind. The attention to detail that makes the unexpected plain to see, and, once it’s identified, the capacity to ask questions about it, are often the essence of discovery.
• This article was amended on 29 July 2016. An earlier version misspelled “mucus” as “mucous”.
