Compared with climate, modelling of ecosystems is at an early stage

EVERY FEW weeks from June 1963 until July 1968, Robert Paine, a zoologist, made the journey from Seattle, where he taught at the University of Washington, across Puget Sound to the rocky shores of Mukkaw bay. There, he had found virtually pristine tide pools that teamed with life—limpets, anemones, mussels, seaweeds and purple-and-orange seastars known as Pisaster ochraceus. The unspoiled landscape offered the perfect setting for what was to become a seminal experiment in ecology. On each visit, Dr Paine systematically removed all the seastars he could find from one patch of rock, lobbing them as far as he could into the waves.