In this blog post, we will examine the coexistence of living things and the dynamic balance of ecosystems through the simple game of rock-paper-scissors.
Rock, paper, scissors! Depending on what you choose, the outcome is clearly decided, but the charm of this game lies in the fact that there are no eternal winners or losers. Despite its simplicity, rock-paper-scissors transcends mere play, serving as an intriguing social experiment that reflects human psychology and strategy. We unconsciously predict the actions of others and adjust our choices based on these predictions, a process that provides important clues to understanding human thinking and decision-making. Research suggesting that the endless cycle of rock-paper-scissors could serve as a model for explaining biological diversity has drawn attention.
A research team observed the rock-paper-scissors relationship in the proliferation competition between three different groups of E. coli bacteria living in the intestines of animals. This study goes beyond simple experimental observation and plays an important role in explaining complex biological interactions. In particular, “group C” produces a toxin called colicin, while “group S” proliferates faster than other groups but is inhibited by colicin. ‘Group R’ has a proliferation rate faster than ‘Group C’ but slower than ‘Group S,’ and is resistant to colistin. These interactions help us understand how organisms influence each other and coexist within a specific ecosystem. In biological systems, species do not simply compete; they create opportunities to support each other’s survival through complex interactions. When two groups are mixed and cultured together, the difference in proliferation rates leads to clear winners and losers in intergroup competition. However, when all three groups are cultured adjacent to each other, one-sided territory invasion occurs at the boundaries between each pair of groups, but ultimately, a three-way coexistence relationship resembling a rock-paper-scissors dynamic is observed. This phenomenon goes beyond simple competition, suggesting the possibility of mutual balance and coexistence.
Another research team administered three E. coli groups to mice and observed the proliferation competition between the groups. What is particularly noteworthy here is that even when one group gained the upper hand at a specific point in time, the dominant group continued to change over time. This suggests that no single species can remain dominant forever in a natural ecosystem and highlights the importance of the ability to adapt to constantly changing environments for the survival of organisms. An ecosystem is not a static system but a dynamic one that is constantly changing and evolving. As a result, while a species may gain an advantage in a specific environment, its position may become unstable over time, and competition may resume as other species adapt to the new environment. This also implies that three groups can simultaneously exist as dominant groups in isolated spaces. Such dynamic changes serve as an important mechanism for maintaining biodiversity.
The above example is often cited as a good illustration of how there may be no absolute winners in an ecosystem. In nature, new ecological balances are formed through constant change. Compared to the clear-cut relationship between two parties in competition, the rock-paper-scissors relationship, which demonstrates the possibility of three parties coexisting, may be a more appropriate model for explaining biological diversity. This goes beyond a mere biological model and provides useful insights for understanding the diverse competitive and cooperative structures in human society. In human society as well, certain groups may temporarily gain an advantage, but over time, new groups emerge in response to changing environmental conditions. In this context, the principle of rock-paper-scissors can serve as an important concept applicable to various social, economic, and political situations.
