Darwin’s theory of natural selection relies on the selfish survival of the fittest. Still, there are numerous examples of adaptive cooperative traits in nature. How can selection favor individuals that carry out costly actions for the benefit of others?
This question – how can cooperative traits evolve – is an old problem in evolutionary biology. Experimental microbiology is a growing source of models to tackle this problem.

P. aeruginosa swarming: a model for the evolution of cooperation

In a recent article (Roditi et al, Molecular Systems Biology) we used swarming motility in the opportunistic pathogen Pseudomonas aeruginosa as a model for the evolution of cooperation. Laura Roditi, the first author, was the first PhD to graduate from our group and is now a postdoc with Manfred Claasen at the ETH in Zurich. The paper was also featured in a popular science article in the Brazilian science Instituto Ciencia Hoje (it’s in Portuguese, but a two year old can learn Portuguese).

Besides the fundamental implications to the evolution of cooperation, unveiling the mechanisms by which microbes stabilize cooperation can have implications to therapy – see this review:

Exploiting social evolution in biofilms
Boyle KE, Heilmann S, van Ditmarsch D, Xavier JB. Current Opinion in Microbiology.