Evolution of specialized microbial cooperation in dynamic fluids

TL;DR

This study uses realistic simulations to explore how physical factors like diffusion and flow influence microbial cooperation and community structure evolution, revealing complex coexistence and resistance to cheating.

Contribution

It demonstrates that physical and mechanical factors significantly impact microbial specialization and community diversity, challenging traditional fitness-based models.

Findings

Physical factors influence community structure evolution.

Generalist communities can resist specialization and cheaters.

Multiple community structures can coexist despite competition.

Abstract

Here, we study the evolution of specialization using realistic computer simulations of bacteria that secrete two public goods in a dynamic fluid. Through this first principles approach, we find physical factors such as diffusion, flow patterns, and decay rates are as influential as fitness economics in governing the evolution of community structure, to the extent that when mechanical factors are taken into account, (1) Generalist communities can resist becoming specialists, despite the invasion fitness of specialization, (2) Generalist and specialists can both resist cheaters despite the invasion fitness of free-riding, (3) Multiple community structures can coexist despite the opposing force of competitive exclusion. Our results emphasize the role of spatial assortment and physical forces on niche partitioning and the evolution of diverse community structures.