  We study the evolution of recombination using a microscopic model developed
within the frame of the theory of quantitative traits. Two components of
fitness are considered: a static one that describes adaptation to environmental
factors not related to the population itself, and a dynamic one that accounts
for interactions between organisms e.g. competition. We focus on the dynamics
of colonization of an empty niche. As competition is a function of the
population, selection pressure rapidly changes in time. The simulations show
that both in the case of flat and steep static fitness landscapes,
recombination provides a high velocity of movement in the phenotypic space thus
allowing recombinants to colonize the highest fitness regions earlier than non
recombinants that are often driven to extinction. The stabilizing effects of
competition and assortativity are also discussed. Finally, the analysis of
phase diagrams shows that competition is the key factor for the evolution of
recombination, while assortativity plays a significant role only in small
populations.
