BIOLOGICAL evolution happens by random mutation and selection. Technological evolution involves selection, too. Products preferred by customers are the ones that reproduce. But since technology is the product of conscious design, the mutation part of the process might reasonably be assumed to be deliberate rather than random.

A study just published in the Proceedings of the Royal Society suggests, however, that this is not always the case. Nicholas Makris and his colleagues at the Massachusetts Institute of Technology, in collaboration with Roman Barnas, a violin maker at the North Bennet Street School, in Boston, have been looking at the evolution of that instrument. One aspect of the process intrigued them in particular—the changing shape, over the years, of the holes in a violin’s body that allow the sound to emerge.

The violin’s oldest European ancestors date from the tenth century. They were called “fitheles”, a word derived from vitula, the Latin for heifer, the source of the gut for the strings. (The Latin word also eventually gave rise to “violin”; “fitheles”, meanwhile, became “fiddle” in a process of linguistic speciation also akin to the biological sort.) The instrument arrived at its modern form between the 16th and the 18th centuries, in the workshops of Cremona, a city in northern Italy that produced the Amati, Guarneri and Stradivari dynasties of luthiers.

Dr Makris and his team noticed that, in the transition from tenth-century fithele to 18th-century violin, the holes on top of the sound box evolved from simple circles to the complex, elongated f-shapes familiar in today’s instruments. They wondered why.