It is well known that if reacting species experience unequal diffusion rate
s, then dynamics that lead to a constant steady state in a "well-mixed" env
ironment can in a spatial setting lead to interesting patterns. In this pap
er, we focus on complementary pattern formation mechanisms that operate eve
n when the diffusion rates are equal. In particular, we can say that when t
he mean-field ODE has an attracting periodic orbit then the stochastic spat
ial model will have large-scale spatial structures in equilibrium. We explo
re this mechanism in depth through the dynamics of the simulator WATOR. (C)
2000 Academic Press.