What can Physarum polycephalum, an acellular slime mold, do according to a team of Japanese researchers?

Physarum polycephalum, an acellular slime mold or myxomycete, is a protist with diverse cellular forms and broad geographic distribution. The “acellular” moniker derives from the plasmodial stage of the life cycle: the plasmodium is a bright yellow macroscopic multinucleate coenocyte shaped in a network of interlaced tubes. This stage of the life cycle, along with its preference for damp shady habitats, likely contributed to the original mischaracterization of the organism as a fungus. P. polycephalum is used as a model organism for research into motility, cellular differentiation, chemotaxis, cellular compatibility, and the cell cycle.

Physarum polycephalum has been shown to exhibit characteristics similar to those seen in single-celled creatures and eusocial insects.

For example, a team of Japanese and Hungarian researchers have shown P. polycephalum can solve the shortest path problem. When grown in a maze with oatmeal at two spots, P. polycephalum retracts from everywhere in the maze, except the shortest route connecting the two food sources.