  The puzzle associated with the cost of sex, an old problem of evolutionary
biology, is discussed here from the point of view of nonequilibrium statistical
mechanics. The results suggest, in a simplified model, that the prevalence of
sexual species in nature can be a natural and necessary consequence of the
discrete character of the nonlinear interactions between couples and their
pathogens/parasites. Mapped into a field theory, the stochastic processes
performed by the species are described by continuous fields in space and time.
The way that the model's parameters scale with subsequent iterations of the
renormalization group gives us information about the stationary emergent
properties of the complex interacting systems modeled. We see that the
combination of one aspect of the Red Queen theory with the stochastic processes
theory, including spatiotemporal interactions, provides interesting insights
into this old Darwinian dilemma.
