The life form that really excites us from the collaborative point of view is pretty unprepossessing – it’s slime mould, the nasty reddish jelly-like stuff you sometimes find under half-rotted bark. Slime mould has fascinated scientists for decades. It’s hard to classify, as it’s not a mould at all. Cellular slime mould is a single-celled, amoeba-like organism that spends most of its time minding its own business. But when resources are scarce, individual slime mould cells start to cooperate to form a more complex organism that behaves as one. What’s more, when slime mould cells get together, they can display surprising levels of apparent ‘intelligence’ – like solving the puzzle of a maze by stretching between two food sources at either end. Then when the crisis is over, they split up and go back to existing as single cellular organisms once more.

Steven Johnson tells the story of slime mould brilliantly in his book Emergence: The Connected Lives of Ants, Brains, Cities and Software. His point is that slime mould displays emergent behaviour – the ‘intelligence’ it demonstrates comes about from aggregating a mass of relatively simple elements. No one element is directing the show: rather, this complex behaviour emerges from the level of individual cells.

The reason we like slime mould so much is rather different. It’s because it has clearly got the hang of how to be a good partner. Slime mould knows when to be independent and when to collaborate. It doesn’t spend all its time as a team – each single cell manages perfectly well on its own for large stretches of time. But when slime mould cells get together, they can do amazing things.