ett, R., 1988. Lecture Notes on Particle Systems and Percolation. Wadsworth & Brooks/Cole Advanced Books & Software, Stamford, CT. [24] Durrett It, Levin SA, 1994. Stochastic spatial models: a user's guide to ecological applications. Philos. T. Roy. Soc. B, 343, 329-350. [25] Ellison, G., 1993. Learning