# The Limits of Our Explanation: A Case Study in Myxococcus xanthus Cooperation

## TL;DR

This paper explores how current theories of cooperation may fail to explain complex social behaviors in Myxococcus xanthus bacteria.

## Contribution

The paper introduces a case study highlighting limitations in evolutionary cooperation theories when applied to ecological and genomic contexts.

## Key findings

- Current theories mischaracterize cooperative problems in game theory.
- Explanatory models are insensitive to ecological and genomic context.
- Cooperative predation in Myxococcus xanthus lacks a satisfactory explanation.

## Abstract

In this article, I demonstrate two ways in which our major theories of the evolution of cooperation may fail to capture particular social phenomena. The first shortcoming of our current major theories stems from the possibility of mischaracterizing the cooperative problem in game theory. The second shortcoming of our current major theories is the insensitivity of these explanatory models to ecological and genomic context. As a case study to illustrate these points, I will use the cooperative interaction of a species of myxobacteria called Myxococcus xanthus. M. xanthus cooperate in many areas of their life cycle—in quorum sensing, social motility, fruiting body formation, and predation. I focus in particular on predation as we have not yet discovered an adequate explanation of how they sustain cooperative predation in the face of developmental cheats. In explaining why we have not, I draw generalizable conclusions that shed light on our use of simplified models to explain real-world behaviors in a variety of organisms.