Slime mold, Physarum polycephalum. Photo by Stephanie Davidson, CC_by_NC_SA

DNews (Discovery News) has an informative and thought-provoking video about slime molds. The narrator, Anthony Carboni, points out that the slime mold, Physarum polycephalum, is a single-celled organism with no nervous system, yet appears to do “intelligent” things like reasoning, making smart decisions, and having a form of memory. What the slime mold is doing is using a set of simple rules to optimize foraging while minimizing energy.

One great thing about slime molds is that while the videos make them look like they move fast, they actually don’t, which means that if you find one (and they occur in a number of places), you can observe them over time without worrying that they’ll run or fly off. You can also cultivate them indoors and try some experimenting on what they like and dislike, and how they optimize routes to food sources. Some of the studies about slime molds have marveled at how they can do things like recreate the railway or highway systems of a country like Spain. It would be interesting to see how a slime mold could layout a walkable city.

There is also an AskNature article about slime molds with some references.