Modelling the neuron as little more than a simple on/off switch is a big mistake (Image: Dan Webber)

LATE at night on a sultry evening, I watch intently as the predator senses its prey, gathers itself, and strikes. It could be a polecat, or even a mantis – but in fact it’s a microbe. The microscopic world of the single, living cell mirrors our own in so many ways: cells are essentially autonomous, sentient and ingenious. In the lives of single cells we can perceive the roots of our own intelligence.

Molecular biology and genetics have driven the biosciences, but have …