Growth dynamics and the evolution of cooperation in microbial populations
Authored by Erwin Frey, Jonas Cremer, Anna Melbinger
Date Published: 2012
DOI: 10.1038/srep00281
Sponsors:
German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
Microbes providing public goods are widespread in nature despite running
the risk of being exploited by free-riders. However, the precise
ecological factors supporting cooperation are still puzzling. Following
recent experiments, we consider the role of population growth and the
repetitive fragmentation of populations into new colonies mimicking
simple microbial life-cycles. Individual-based modeling reveals that
demographic fluctuations, which lead to a large variance in the
composition of colonies, promote cooperation. Biased by population
dynamics these fluctuations result in two qualitatively distinct regimes
of robust cooperation under repetitive fragmentation into groups. First, if the level of cooperation exceeds a threshold, cooperators will take
over the whole population. Second, cooperators can also emerge from a
single mutant leading to a robust coexistence between cooperators and
free-riders. We find frequency and size of population bottlenecks, and
growth dynamics to be the major ecological factors determining the
regimes and thereby the evolutionary pathway towards cooperation.
Tags
Competition
Group selection
Altruism
System
Kin selection
Bacterial biofilms
Pseudomonas-aeruginosa
Ameba dictyostelium-discoideum
Sociobiology
Defection