Since animal coats and tiger-bush patterns look alike, Dr Kealy and Dr Wollkind reasoned that the ways they are produced might be akin, too at least mathematically.

ECONOMIST: Mathematical ecology

This insight allowed Dr Kealy and Dr Wollkind to create equations that, once plugged into computer simulations of reaction-diffusion processes, produce all manner of lifelike tiger-bush schemes, including the most intricate sort.

ECONOMIST: Mathematical ecology

Dr Kealy's model, by contrast, is spot-on.

ECONOMIST: Mathematical ecology