The emergence of cooperation from a single mutant during microbial life cycles

Anna Melbinger, Jonas Cremer, Erwin Frey

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10 Citations (Scopus)


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.
Original languageEnglish
Article number 20150171
Number of pages8
JournalJournal of the Royal Society Interface
Issue number108
Publication statusPublished - Jul-2015
Externally publishedYes


  • cooperation
  • evolution
  • public good

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