Environmental Stress Can Favor Cooperation by Triggering an Adaptive Race Between Cooperators and Cheaters
type: CreativeWork
description: Resolving the apparent paradox of the almost universal success of cooperation despite its vulnerability to cheating has been the focus of decades of theoretical and experimental research. Cooperators pay a cost to produce common goods that can be used by any individual, including cheaters. Cheaters consume but do not contribute fairly to the production of common goods, and are therefore more fit than cooperators. Cheaters should therefore displace cooperators, resulting in the eventual demise of cooperation known as “the tragedy of the commons.” How can cooperation persist despite the threat of cheaters? Previous research has shown that mechanisms such as spatial clustering of cooperators or cheater-sanctioning can help cooperation survive cheating. I have discovered an entirely new mechanism—adaptation to environmental stress—that favors cooperation over cheating. I started by testing whether the known pro-cooperation mechanisms are the only mechanisms that can stabilize cooperation. I employed a synthetic yeast cooperator-cheater system based on the release or exploitation of essential metabolites to systematically remove all known cheater control mechanisms, which would have been impossible if using natural cooperative systems. Surprisingly, I found that despite cooperators being less fit than cheaters, some cocultures rapidly purged cheaters, while in others cheaters dominated and drove cocultures and themselves extinct. Using deep sequencing and phenotypic analyses, I demonstrated the molecular mechanism responsible for this unanticipated outcome. Essentially, the nutrient-limited cooperative environment acted as a stress on both cooperators and cheaters. I found that this stress created a selective pressure which triggered an “adaptive race” between cooperators and cheaters to sample from the same pool of fitness-enhancing mutations. If cooperators sampled the best mutation, cooperators would win the race and continue to proliferate. If cheaters won the race, …
abstract: Resolving the apparent paradox of the almost universal success of cooperation despite its vulnerability to cheating has been the focus of decades of theoretical and experimental research. Cooperators pay a cost to produce common goods that can be used by any individual, including cheaters. Cheaters consume but do not contribute fairly to the production of common goods, and are therefore more fit than cooperators. Cheaters should therefore displace cooperators, resulting in the eventual demise of cooperation known as “the tragedy of the commons.” How can cooperation persist despite the threat of cheaters? Previous research has shown that mechanisms such as spatial clustering of cooperators or cheater-sanctioning can help cooperation survive cheating. I have discovered an entirely new mechanism—adaptation to environmental stress—that favors cooperation over cheating. I started by testing whether the known pro-cooperation mechanisms are the only mechanisms that can stabilize cooperation. I employed a synthetic yeast cooperator-cheater system based on the release or exploitation of essential metabolites to systematically remove all known cheater control mechanisms, which would have been impossible if using natural cooperative systems. Surprisingly, I found that despite cooperators being less fit than cheaters, some cocultures rapidly purged cheaters, while in others cheaters dominated and drove cocultures and themselves extinct. Using deep sequencing and phenotypic analyses, I demonstrated the molecular mechanism responsible for this unanticipated outcome. Essentially, the nutrient-limited cooperative environment acted as a stress on both cooperators and cheaters. I found that this stress created a selective pressure which triggered an “adaptive race” between cooperators and cheaters to sample from the same pool of fitness-enhancing mutations. If cooperators sampled the best mutation, cooperators would win the race and continue to proliferate. If cheaters won the race, …
author: Waite, Adam James
language: en_US
keywords: evolution of cooperation; experimental evolution; genetic hitchiking; metapopulation modeling; phenotypic heterogeneity; synthetic biology
date published: 2013-11-14
date modified: 2026-07-24T05:58:03Z
provider: University of Washington
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Washington

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1773/24226