Physarum Polycephalum

Sam Staas

Physarum Polycephalum is an organism, commoly known as Slime Mold. It is infact not a mold at all, but a single-celled organism that joins together with other cells to form a mass super-cell maximize its resources. Within one slime mold, one might find thousands to millions of nuclei, working as one. Slime mold is found in the woods, eating rotten greenery.

Heather Barnett is one of the many artists along with scientists who have chosen to create artwork and study study slime mold. When Barnett was fist gifted slime mold, the only instructions she was given was that it liked it dark and damp, and its favorite food is oats. A living organisms like this mold was nothing uncommon to Barnett, who is an artist who has worked with many other plants and bacteria. Barnett would grow the mold in her studio on a black paper to bring out its gorgeous yellow colors, which would show its trail it left behind very vividly. She began with experimenting with its diet and observing how it grows and networks. She observed the chain it made between food sources, and the trails it would leave behind, showing where it had been. The slime acted as thought it had a brain and would move on from one petri dish when all its resourced were depleted. Below you can see the mold on its food source, and the white areas being the trails its leaving behind.

Now slime mold only grows about one centimeter and hour, but with a time lapse, its movement can be easily observed. Barnett was interested in how once the slime mold would finish eating a pile of oats, it would go off to map its surrounding territory, as if it moved with intention.

A team of scientists at Hokkaido University in Japan studied the mold by filling a maze with the slime. The slime mold worked together by forming one mass cell, filling up the maze completely. They then introduced oats at two points in the maze, and the mold proceeded to form a commotion between the food, solving the maze. There were four possibly solutions through the maze, yet every time they performed this experiment the slime mold would find the sourest and most efficient route. After this and a couple other experiments, they deduced that slime mold was able to learn and grow. One last experiment was performed: the slime mold was placed on a empty substrate covered in oats. The slime mold begins with expanding out in a branching pattern. As the slime mold grows, it finds the food, and forms a connection with itself and keeps searching for food. Twenty Six hours later, the mold had formed a strong network between the oats. Infact the oats were representative of the city of Tokyo and its surrounding railway stations. The slime mold had re-created the Tokyo transportation network. A system that too 100 of years for humans to develop, took the slime mold 26 hours.

Tokyo Transportation Network

This organism is much more than thousands of nuclei working together, it is a complex system that is living, breathing, and learning. It can understand its environment and use that to map out systems that would take humans years to accomplish. The hopes are that it will be implemented into urban planning to create more efficient transportation systems. It can also be used to create beautiful artwork. Here is a piece done by an artist using glow-in-the-dark slime mold.

Bibliography: 

Barnett, H. (2014). What humans can learn from semi-intelligent slime. Retrieved February 13, 2018, from https://www.ted.com/talks/heather_barnett_what_humans_can_learn_from_semi_intelligent_slime_1/transcript#t-435001

Heather Barnett's Page. (n.d.). Retrieved February 13, 2018, from http://slimoco.ning.com/profile/HeatherBarnett

The Physarum Experiments. (2017, April 08). Retrieved February 13, 2018, from http://heatherbarnett.co.uk/work/the-physarum-experiments/

Some imaged from Google.