  Finite-size fluctuations arising in the dynamics of competing populations may
have dramatic influence on their fate. As an example, in this article, we
investigate a model of three species which dominate each other in a cyclic
manner. Although the deterministic approach predicts (neutrally) stable
coexistence of all species, for any finite population size, the intrinsic
stochasticity unavoidably causes the eventual extinction of two of them.
