A SLIMY road planner has rearranged the UK's motorway network - and all in exchange for a hearty meal. A corrupt politician at work? No, it's Physarum polycephalum, a yellow slime mould normally found growing in piles of rotten leaves and logs.
Jeff Jones and Andrew Adamatzky, specialists in unconventional computing at the University of the West of England in Bristol, wondered if biology could provide an alternative to conventional road planning methods. To find out, they created templates of the UK using a sheet of agar on which they marked out the nine most populous cities, excluding London, with oat flakes. Then, in the place of London, the pair introduced a colony of P. polycephalum, which feeds by spawning tendrils to reach nutrients, and recorded the colony's feeding activity (see picture).