Slimy, smart and hungry: the curious world of slime moulds

They're smarter than some of the world’s best engineers, and have a body more simple than any plant or animal you've ever seen. This weeks Wacky Wednesday feature is the slime mould.

Neither slime nor fungi, slime moulds are a loose group of eukaryotic organisms which can live as single cells. Technically a member of the Protista kingdom, there are over 900 different species of slime mould which can be found all around the world.

Quick Facts:

• Scientific name: Mycetozoan group of amoebozoa
  

• Geographic location: Worldwide
  

• Distinguishing feature: Yellow, branching networks
  

• Conservation status: Not threatened

When appropriate, these organisms can come together to form a larger organism. Some of the largest slime moulds are several square meters wide, and weigh over 20 kilograms! When they become multicellular organisms they are better equipped to sense the air and detect nearby sources of food.

Whilst their favourite snack in the lab is oats, out in the wild you can find them on soil, lawns, or rotten logs due to their craving for microorganisms found in decaying plant material. Slime moulds have been studied for many years now due to scientific interest in how they make decisions and learn from past experiences.

The Mycetozoa group which slime moulds are part of. (1904)

Scientists like Audrey Dussutour, from the National Center for Scientific Research in France have taught slime moulds to change their behaviour towards unappealing substances like caffeine and salt. Observing slime mould behaviour is a slow process since they move at 1 millimetre per hour, but researchers are excited by the primitive learning that they exhibit.

Historically, we have associated learning exclusively with organisms that have a nervous system. Since slime moulds are unicellular and containing millions (and sometimes billions) of nuclei, new theories regarding the requirements for learning have been proposed.

Audrey and her colleagues observe that slime moulds pulse and expand in response to stimuli. The more stimulating the environment, the faster they pulse. This response is a potential method for spreading information throughout the cell.

https://www.youtube.com/watch?v=GY_uMH8Xpy0

In addition to spreading information within their cell, slime moulds can respond and interact with their environment in creative and efficient ways. Over a decade ago, scientists placed oats in a fashion that modelled Tokyo and the surrounding towns. The slime mould was placed in the arena and preceded to spread out in a network so it could reach the yummy treats. Within no time, the slime mould managed to accurately recreate the Tokyo subway system, a sophisticated and efficient network of paths. Watch the experiment here!

Fuligo septica, also known as the "dog vomit" slime mold

Scientists are now considering how they can implement slime mould’s genius in other areas of human society. One of the areas that excites me most is driverless cars.

Would you trust a driverless car that was controlled by a slime mould program? Comment down below!