Fig. 2.

Function-and-die Terraformation motif. Here a given substrate R is being generated at a given rateand provides physical substrate to the synthetic population. The TM motif in (a) is based on the modification ofan extant species following the same criteria that described in figure 1, whereas in (b) we just assume that the engineered species has been improved to attach efficiently to the substrate. In both cases, the engineered species could perform a function while degrading the waste material ∅. Candidate examples are plastic ocean debris, where many species are known to live (c) or concrete cracks (d). figures (c) and (d) have been adapted from [11, 15], respectively.