The genotypic view of cooperation and competition in microbial communities
Kevin Foster, Professor of Evolutionary Biology - University of Oxford
Location: 10 Guyot Hall
Date/Time: 05/28/13 at 2:00 pm - 05/28/13 at 3:00 pm
Since Darwin, evolutionary biologists have been fascinated by cooperative behavior. Honeybee workers labor their whole life without reproducing, birds make alarm calls, and humans often help one another. One major group that remains relatively unexplored, however, is the microbes whose full spectrum of sociality only recently came to light. Microbes often live in large dense groups where one cell can strongly affect the survival and reproduction of others. But do microbes typically help or harm those around them and can we identify the factors that promote cooperation over competition? We study these questions using a diversity of systems, including computer simulations, pseudomonad bacteria and budding yeast. We find that single-genotype patches naturally emerge in microbial groups, which creates favorable conditions for cooperation within a particular genotype. Experimental evolution in bacteria shows that this process drives extremely strong natural selection for cooperative adaptations that can be understood at the molecular scale. Moreover, some microbes actively adjust both genotypic assortment and investment into social traits in a way that promotes cooperation within a genotype. However, our work on interactions between different microbial genotypes suggests that, here, the evolution of competitive phenotypes is more likely than cooperation. This leads us to a simple model – the genotypic view – that predicts microbes will evolve to help their own genotype but harm most other strains and species that they meet.
Category: Special Seminar