Public and Private Effects of Cooperation on Survival and Growth
Abstract
Cooperation plays a significant role in all aspects of life where multiple individuals interact for the purpose of survival. Cheaters do not pay the cost of cooperation and they can take advantage of cooperators. In theory, cheating should undermine cooperation as an evolutionary stable strategy. However, cooperation continues to persist in multiple biological systems. One possibility to explain the stability of cooperation is the use of an impure public good. This public good can be shared amongst everyone in a population (providing a public benefit), and is used to facilitate cooperation. However, there is a private benefit of this public good that redounds only to the producer. Though theoretically possible, there is a lack of experimental information demonstrating how the public and private benefit of a public good affect the survival of populations. To address this question, we used simulations coupled with experiments using a microbial cooperator-cheater system. Using Escherichia coli that express a β-lactamase public good, we determined how the contributions of the public and private benefit regulate population collapse. We observed that our microbial populations were most sensitive to collapse when initiated at an intermediate fraction of cooperators. Decreasing the private benefit of β-lactamase expression increased the maximum sensitivity to population collapse. Using both colony forming unit measurements and simulations, we show that the near simultaneous collapse of both cooperator and cheater populations leads to increased sensitivity. Our findings demonstrate the significance of public and private benefits in relation to populations that rely on cooperation for survival.
Faculty Sponsors
Dr. Robert Smith, Dr. Louis Nemzer
Project Type
Event
Location
Alvin Shermany Library
Start Date
4-5-2019 1:00 PM
End Date
4-5-2019 5:00 PM
Public and Private Effects of Cooperation on Survival and Growth
Alvin Shermany Library
Cooperation plays a significant role in all aspects of life where multiple individuals interact for the purpose of survival. Cheaters do not pay the cost of cooperation and they can take advantage of cooperators. In theory, cheating should undermine cooperation as an evolutionary stable strategy. However, cooperation continues to persist in multiple biological systems. One possibility to explain the stability of cooperation is the use of an impure public good. This public good can be shared amongst everyone in a population (providing a public benefit), and is used to facilitate cooperation. However, there is a private benefit of this public good that redounds only to the producer. Though theoretically possible, there is a lack of experimental information demonstrating how the public and private benefit of a public good affect the survival of populations. To address this question, we used simulations coupled with experiments using a microbial cooperator-cheater system. Using Escherichia coli that express a β-lactamase public good, we determined how the contributions of the public and private benefit regulate population collapse. We observed that our microbial populations were most sensitive to collapse when initiated at an intermediate fraction of cooperators. Decreasing the private benefit of β-lactamase expression increased the maximum sensitivity to population collapse. Using both colony forming unit measurements and simulations, we show that the near simultaneous collapse of both cooperator and cheater populations leads to increased sensitivity. Our findings demonstrate the significance of public and private benefits in relation to populations that rely on cooperation for survival.
