  Classical models for competition between two species usually predict
exclusion or divergent evolution of resource exploitation. However, recent
experimental data show that coexistence is possible for very similar species
competing for the same resources \textit{without} niche partition. Motivated by
this experimental challenge to classical competition theory, we propose an
individual-based stochastic competition model, which is essentially a
modification of a deterministic Lotka-Volterra type model. The proposed model
of competition dynamics incorporates the effects of a discrete genotype, which
determines the individual's adaptation to the environment, as well as its
interaction with the other species.

Populations and Evolution