Can organisms without a brain still exhibit intelligence? This question has long intrigued scientists, and recent research from Tohoku University and Nagaoka College in Japan has shed new light on the decision-making processes in fungi. The study, published in Fungal Ecology on September 12, 2024, reveals that these seemingly simple organisms possess a level of basal cognition that challenges our understanding of intelligence.
The Hidden World of Mycelial Networks
"You'd be surprised at just how much fungi are capable of," remarks Yu Fukasawa of Tohoku University. "They have memories, they learn, and they can make decisions. Quite frankly, the differences in how they solve problems compared to humans is mind-blowing."
Fungi grow by releasing spores, which can germinate and form long, spidery threads underground known as mycelium. While we typically only see the fruiting bodies (mushrooms) on the surface, a vast network of interconnected mycelium lies beneath our feet. This network serves as a communication system, sharing information in a manner reminiscent of neural connections in the brain.
Observing Fungal Decision-Making in Action
The researchers examined how a wood-decaying mycelial network of Phanerochaete velutina, a cord-forming fungus, responded to two different situations: wood blocks placed in a circle versus a cross arrangement. If the fungi lacked decision-making skills, they would simply spread out from a central point without consideration for the position of the blocks. However, the results were far more intriguing.
In the cross arrangement, the degree of connection was greater in the outermost four blocks. The researchers hypothesized that these outer blocks serve as "outposts" for the mycelial network to embark on foraging expeditions, necessitating denser connections. Conversely, in the circle arrangement, the degree of connection was uniform across all blocks, with the centre remaining clear. This suggests that the mycelial network recognized no benefit in overextending itself in an already well-populated area.
Implications for Ecosystem Understanding and Evolution of Cognition
These findings indicate that mycelial networks can communicate information about their surroundings throughout the entire system, adjusting their growth patterns based on environmental cues. This level of adaptive behaviour in fungi opens up new avenues for understanding how biotic ecosystems function and how different types of cognition evolved in organisms.
As our comprehension of the mysterious world of fungi continues to expand, studies like this highlight the importance of looking beyond traditional definitions of intelligence. By broadening our perspective, we may unlock new insights into the complex web of life that exists just beneath the surface of our world.