What’s worse, performing this calculation gets exponentially harder the more cities are added to the route.
Specifically, the Physarum polycephalum slime mold. Physarum polycephalum is a very simple organism that does two things: it moves toward food and it moves away from light.
Millions of years of evolution has made Physarum abnormally efficient at both of these things.
The Keio University researchers used this efficiency to build a device to solve the traveling salesman problem.
They set the amoeba in a special chamber filled with channels, and at the end of each channel the researchers placed some food.