Brainless Slime Mold Smarter Than You Think
October 9, 2012

Brainless Slime Mold Smarter Than You Think

Michael Harper for — Your Universe Online

Nothing sounds dumber than “Slime Mold.” This might even be one of the more demeaning insult in sophomoric lexicon, as nothing sounds worse. Yet, for all its off-putting properties, (the slime, the mold) this little organism is fascinating to scientists and researchers, studying how it is able to grow, move and expand.

The makeup of slime mold is relatively simple: A community of single-celled spores which have combined their efforts to seek and devour any new bacteria and fungi for the good of the group.

As an amalgamation of cells, a slime mold does not come equipped with a brain, led instead by the instinct and primordial need of the group.

Researchers have recently discovered, however, that even without a brain (or a central nervous system, for that matter) slime molds are able to intelligently navigate and learn from their past via a sort of “external memory.”

Researchers at the University of Sydney, Australia put some slime mold to the test as they watched and learned. Using the creatively titled “U-Shape Trap Test,” these researchers placed a U-shaped barrier in a petri dish along with a slime mold culture and observed as it grew and traveled. Other molds and cultures may have grown undeterred by this trap, overtaking it or ignoring it altogether. The slime mold behaved in a completely different way: It “bumped” into the U-shaped barrier, then moved along the trap, testing its boundaries as it went along before finally working its way out of the trap and into the rest of the open petri dish.

“This is just another cool thing that slime mold can do,” said biologist and lead author Chris Reid, according to Cosmos Magazine.

“Slime mold shouldn´t be able to do a lot of things because it´s just a single cell and it doesn´t have a brain,” said Reid. “It´s supposed to be acting on this very primitive level, but repeatedly, research has shown it can solve complex tasks.”

According to the research by Reid and team, slime molds use a similar technique to move around obstacles as ants, leaving behind a chemical trail to reference when making decisions about the group. Instead of making the same mistake, running into the same obstacle, the slime mold knows to continue looking for new ground they´ve yet to cover as they seek out potential food sources.

According to Reid, this sort of chemical Hansel and Gretel is known as “externalized memory,” which was “probably used by primitive cells before there was even multi-cellularity.”

This kind of memory may not be as evolutionarily advanced as the kind of memory other animals (such as humans) use, but according to Reid, it´s certainly a first step.

“It allows [slime mold] to solve problems that these days we use big brains to solve, but they didn´t — and still don´t — need them to solve similar problems,” said Reid.

This isn´t the first time Slime molds have surprised researchers, of course. In 2008, Japanese researchers from Hokkaido University won the IgNobel prize for proving slime mold was capable of solving complex problems by “mapping” out the most efficient route of a maze. With a food source placed at either end of the maze, this slime mold was able to first solve the maze, then learn from any errant turns to develop the most efficient way to get back and forth between two food sources.

Insulters, take note: comparing someone to slime mold might not be the slanderous statement you once thought.