title: The emergence of cooperation from a single mutant during microbial life cycles.
abstract: Cooperative behaviour is widespread in nature, even though cooperating individuals always run the risk of being exploited by free-riders. Population structure effectively promotes cooperation given that a threshold in the level of cooperation was already reached. However, the question how cooperation can emerge from a single mutant, which cannot rely on a benefit provided by other cooperators, is still puzzling. Here, we investigate this question for a well-defined but generic situation based on typical life cycles of microbial populations where individuals regularly form new colonies followed by growth phases. We analyse two evolutionary mechanisms favouring cooperative behaviour and study their strength depending on the inoculation size and the length of a life cycle. In particular, we find that population bottlenecks followed by exponential growth phases strongly increase the survival and fixation probabilities of a single cooperator in a free-riding population.
authors.affiliation: Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany Department of Physics, UCSD, 9500 Gilman Drive, La Jolla, CA 92093, USA amelbinger@ucsd.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Melbinger
authors.affiliation: Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany Department of Physics, UCSD, 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors.forename: Jonas
authors.initials: J
authors.lastname: Cremer
authors.affiliation: Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany.
authors.forename: Erwin
authors.initials: E
authors.lastname: Frey
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism*; D059013:Microbial Consortia / Q000502:physiology*; D008954:Models, Biological; D009154:Mutation
keywords: cooperation; evolution; public good