Compared to mold, humans know next to nothing about creating efficient networks. The single-celled organism Physarum polycephalum, a slime mold, grows outward in search of food, optimizing along the way to make its network of branches the shortest, quickest, and strongest paths to where it wants to go—even in a maze.
Researchers are beginning to learn how our own networks—like those of railways and roads—might be improved by watching how the so-called "many-headed slime" behaves under the same circumstances, extrapolating clues as to how to ease congestion and forge better routes between cities and stations.
Andrew Adamatzky, a professor at the University of the West of England in Bristol, has used slime mold to map roadways for cities all over the world, with pieces of oatmeal representing major urban areas. For instance, here’s how slime suggests we should connect the roads of the Iberian peninsula:
Salt is toxic to the mold, so it can be used to model what should happen when things go wrong, like when there’s a highway pileup or flooded road. When the mold detects salt, it strengthens other networks or reroutes in response, providing insight into how transportation planners might prepare a contingency plan.
Biomimicry, the study of biological systems applied to complex human problems, is a useful tool for reexamining how our cities function. Humans have only been building cities for thousands of years. Slime molds have been doing their thing for at least millions of years—maybe even a billion. We could learn a thing or two from them.