How Can Slime Mold Think Without a Brain?

complex problems. There are over nine hundred species of slime molds living in the soils, leaf litter, and rotten logs of this planet and other appropriately damp and humid areas like maybe your bathroom. A Researchers have found a slime mold cast an amber dating back at least one hundred million years that remains entirely unchained from one you could find today. A slime molds in general, though, have probably been squishing their way around Earth for around a billion years.

It's possible that they're one of the first multicellular ish organisms created by single cells joining and working together. Slime molds are a really diverse group. They can appear in any color except true green, a being that they lack chlorophyll. Some called cellular slime molds live mostly as a single cell, but may collect with others in a swarm in response to chemical signals like food shortage or gotapprocreate now. Others, called plasmordial slime molds, spend their entire lives as one

humongous organism enclosed in a single membrane. These are what happen when thousands of single cells meet up and fuse together. Either way, Once the cells of a slime mold are in a collective, they can network and share resources. Slime molds can form up in the shape of delicate lattices or bulbous masses. They can remain microscopic or form collectives ten feet long or longer now that's about three meters.

Given the motivation of, for example, finding food, those collectives are capable of crawling like worms, towards a source of nutrients or light, where nutrients are more likely to be. The thing all slime molds have in common is their life cycle, loosely resembling that of a fungus, which is

why taxonomists lump them in the fungi kingdom for so long. Basically, when they vacuumed as much food out of their environs as they can, they turn their bodies into clusters of spore packets, usually on stalks and sometimes wildly colored, called sporangia. These fruiting bodies disperse a fine mist of spores into the air, which germinate wherever they fall. The single celled organisms that spring from these spores start the slime mold life cycle over again. For the article, this episode is

based on How Stuff Works. Spoke by email with Tanya Laddie, who studies slime molds in the School of Life and Environmental Sciences at the University of Sydney. She said, we still know very little about the ecology of wild slime molds. For example, how they interact with other organisms and what

role they play in ecosystems is still somewhat mysterious. A Lattie studies cognition in both slide molds and insects, and though we don't give insects much credit for their intelligence, with slime molds, the already tricky concept of cognition gets even weirder. Alattie said, slime molds and social insects are both decentralized systems, where there is no leader in charge

of decision making. However, in the case of insects, each individual operates both at the india visual level they have brains, and at a collective level in slime molds, it's much harder to even define what an individual is. We humans rely on our brains for cognition, but even without a giant brain such as ours, other animals do have the ability to reason, learn, plan, and solve complex problems. A take, for instance, the octopus, a cephalopod closely related to clams

and snails. It has a brain, but most of its neurons are spread throughout its squishy body, mostly in its arms. Still, an octopus has an undeniable intelligence. It can learn how to open new kinds of containers to get snacks. It can tell the difference between humans who are dressed identically, or even make an escape from a tank, out a drain pipe and back into the ocean. But this impressive

cognitive functioning bears no physiological relation ship to hours. The neural processing equipment of an octopus evolved basically completely separately from ours because our evolutionary lineages separated over four hundred and sixty million years ago, but slime molds don't have brains or even anything that resembles a neuron. There's a lab friendly slime mold species named Physarum polycephalum, which means many headed slime mold, though it's been affectionately nicknamed the

blob by researchers. It's bright yellow in color and can move in gloopy filaments that look a bit like fans of coral Researchers found that it can solve mazes. When scientists place food at the end of a maze, the mold will extend tendrills down different corridors and back out of dead ends until it finds the food, all within just a few hours. So while the process of learning is completely different in a slime mold versus an octopus versus a human, in each case, the outcome can look

basically the same. One type of learning slime molder capable of is habituation. You do this too. You can get used to the temperature of a cold lake after a few minutes, or to the initially unpleasant buzzing sound of

a fluorescent light in a room. Your brain helps you ignore the annoying sensation of the cold or the noise, and similar to humans, the aforementioned blob can habituate to environments and chemicals that it doesn't love acidic, dusty, dry, salty places, or chemicals like caffeine or quinine if it means it's going to get rewarded for putting up with it. And not only can slime mold habituate to less than ideal circumstances if it means they'll be rewarded, they also

seem to be capable of memory. The blob, for example, seems to be able to remember things. An experiment involving slime molds the intentionally habituated to salt, a known repellent, before going into a dormant period, showed that they remembered how to become habituated to living in a very salty

environment after a year of lying dormant. They also seem to be able to decide which direction to travel based on food that they've encountered there before, and researchers are still exploring slime mold's capacity for and mechanisms of processing information. The hope is that by figuring out how a decentralized intelligence like a slime mold functions, maybe we can learn

something from them. Today's episode is based on the article Brainless Footless slime molds are Weirdly Intelligent and Mobile on how stuffworks dot Com, written by Jesslin Shields. Brain Stuff is production of iHeartRadio in partnership with how stuffworks dot Com and as produced by Tyler Klang. Four more podcasts my heart Radio, visit the iHeartRadio app podcasts, or wherever you listen to your favorite shows.