Can rock-paper-scissors games explain the mechanisms of biodiversity maintenance and coexistence in ecosystems?

A new study suggests that the win-loss structure of a rock-paper-scissors game can be used as a model to explain biodiversity. Rock-paper-scissors relationships in the competition for proliferation among E. coli populations reveal the potential for interactions and coexistence among organisms, with important implications for understanding the complex balance of ecosystems.

 

Rock, paper, scissors, and bo! The beauty of this game is that there are no permanent winners and no permanent losers. Despite its simplicity, rock-paper-scissors is more than just a game; it’s a fascinating social experiment that reflects human psychology and strategy. We subconsciously predict our opponents’ behavior and adjust our choices based on these predictions, a process that provides important clues to understanding human mindsets and decision-making processes. It’s fascinating to see that this endless rock-paper-scissors relationship could be a model for explaining biodiversity.
A team of researchers observed the rock-paper-scissors relationship in a competition for proliferation among three different populations of E. coli bacteria that live in the gut of animals. This study goes beyond simple experimental observation to explain complex biological interactions. Specifically, population C produces a toxin called colicin, and population S proliferates at a faster rate than the other populations, but its growth is inhibited by colicin. Population R proliferates faster than Population C and slower than Population S, but is resistant to colicin. These interactions help us understand how organisms in a given ecosystem can influence each other and coexist at the same time. In biological systems, species don’t just compete, but complex interactions create opportunities for them to help each other survive. If two of the three populations are cultured separately, it is clear that they will compete for reproduction due to differences in their growth rates. On the other hand, when the three populations are cultured in close proximity to each other, the boundaries between each two populations show unilateral territorial aggression, but as a result, a coexistence between the three parties is observed, like a rock-paper-scissors relationship. This phenomenon goes beyond simple competition and suggests the possibility of mutual balance and coexistence.
Another team of researchers injected three E. coli populations into the intestines of mice and looked at the competition for proliferation between them. Of particular note, they found that even though one population was dominant at a given point in time, the dominant population kept shifting over time. This suggests that in natural ecosystems, no one species can be dominant forever, and shows how important the ability to adapt to an ever-changing environment is to the survival of organisms. Ecosystems are not static systems, but rather dynamic systems that are constantly changing and evolving. As a result, a species may dominate in a particular environment, but over time, its position will falter, and competition will resume as other species adapt to the new environment. This also means that three populations can exist as dominant groups simultaneously in different isolated spaces. This dynamic change is an important mechanism for maintaining biodiversity.
The above examples are good examples of how there may not be absolute dominance in an ecosystem. In nature, new ecological equilibria are formed with constant change. Compared to bilateral relationships, where there is a clear winner and loser, the rock-paper-scissors relationship, where three parties can coexist, may be a more appropriate model for explaining biodiversity. Beyond just biological models, this has useful implications for understanding the different structures of competition and cooperation in human societies. In human societies, certain forces may temporarily dominate, but over time, new forces emerge in response to changing environments and conditions. In this context, the principle of rock-paper-scissors is an important concept that can be applied to a variety of social, economic, and political situations.