I will present a spatial individual-based model describing competition between two bacterial species in a fluid environment.  When the two species reproduce at the same rate, but diffuse at different speed, I will show that stochastic fluctuations lead to a selective advantage for the fastest species. When competing individuals are transported by a fluid flow, as in the case of marine populations, the outcome of competition is radically altered, leading to a novel coexistence scenario.

References:

S. Pigolotti and R. Benzi, Phys. Rev. Lett. 112, 188102, 2014
S. Pigolotti, R. Benzi, P. Perlekar, M.H. Jensen, F. Toschi, and D.R. Nelson, Theo. Pop. Biol. 84:72-86, 2013
S. Pigolotti, R. Benzi, M. H. Jensen, D. R. Nelson, Phys. Rev. Lett. 108, 128102, 2012

Personal Homepage: http://www.nbi.dk/~pigo/research.html