Proliferation assisted transport in a random environment

We investigate the competition between barrier slowing down and proliferati on induced superdiffusion in a model of population dynamics in a random for ce field. Numerical results in d = 1 suggest that a new intermediate diffus ion behaviour appears. We introduce the idea of proliferation assisted barr ier crossing and give a Flory-like argument to understand qualitatively thi s nontrivial diffusive behaviour. A renormalization group analysis close to the critical dimension d(c) = 2 confirms that the random force fixed point is unstable and flows towards an uncontrolled strong coupling regime.