The Environmental Games

For over 4 billion years, the environment has guided evolutionary selection by presenting biological entities with opportunities and challenges and by mediating their interactions. In evolutionary game theory (EGT), the replicator equation defines the game according to direct interactions between biological entities. Eco-evolutionary models have described environmental feedback by modeling environmental states dynamically. Yet, these models channel environmental pressures through the direct interaction coefficients instead of creating a distinct game. Here, I invent Pure Environmental Games (PEGs) and formally introduce the environment as a strategy in EGT. The PEGs describe the neutral selection game and environmental games operating in parallel. Through the net specific accumulation rates of microbes parametrized by the environmental state, Environmental Biotechnology—an engineering discipline designing wastewater treatment plants worldwide — offers a collection of instances of PEGs. The environmental strategy resists invasion from biological strategies when it is a strict Nash equilibrium. The PEGs provide a template for identifying regimes of environmental selection within an environmental game (e.g., the r/K selection game). This mapping identifies persistence as a new dynamic regime under extinction. In a closed system, life persists by partnering with the environmental strategy consistent with Schrödinger’s negative entropy.