The Behavioural and Evolutionary Ecology of Social Behaviour in the Social Amoeba Dictyostelium discoideum

  • Neil Buttery

    Student thesis: Phd


    The maintenance of cooperation and altruism in the face of manipulation by exploitative cheaters that reap the benefits of cooperative acts without paying the associated costs is a conundrum in evolutionary biology. Cheaters should spread through a population causing it to crash, yet cooperation is common. There are many models and theories that attempt to explain this apparent contradiction.The social amoeba Dictyostelium discoideum, like many microbial species has been used as a model organism to test these theories and to begin to understand the genetic mechanisms behind social behaviours.The aim of this PhD project is to quantify the interactions that occur between naturally-occurring genotypes during social competition in order to identify the types of cheating behaviours and to understand the evolutionary consequences of such behaviours. I first demonstrate that there is a social hierarchy of genotypes and that cheaters can increase their own fitness by increasing their own spore allocation or decreasing their partner's allocation the precise nature of which is dependent upon unique interactions between each competing pair. I also show that the outcome of social competition is dependent upon the physical environment where it can be significantly reduced, or even avoided by segregation of genotypes during development. Finally, it is demonstrated in a collaborative project that much of the observed social behaviour can be explained in terms of the production of and response to developmental signals.
    Date of Award31 Dec 2010
    Original languageEnglish
    Awarding Institution
    • The University of Manchester
    SupervisorChristopher Thompson (Supervisor)


    • Dictyostelium discoideum
    • social microbes
    • genetic variation
    • social amoebae
    • cheating
    • cooperation
    • social evolution
    • developmental biology

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