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Slime mould is a fascinating organism to study, because it has two distinctive phases in its lifecycle. When food is plentiful, in the form of bacteria, this species exists as free-living and independent amoeba. However, as soon as food becomes scarce, something quite extraordinary happens; the previously independent amoeba begin to act as a coherent whole. After an eight-hour interphase process, some of the amoeba start to aggregate around cells, which act as centres, sending out chemical signals consisting of cAMP.

There are two forms of action. In the first instance, cells which receive the signal then repeat the signal by sending it out to other cells. In the second instance, cells receiving the signal move towards the origin of the signal. This behaviour is shown in the beautiful black and white films of biology professor emeritus John Bonner, who has studied slime mould for almost…