Simulations of genetic network evolution

In many population genetic models, mutations are assigned a fitness effect - an assigned genotype -> fitness map.  Simulations can then explore how gene frequencies change over time under a number of demographic scenarios.  An alternative is to use a generative model - often times a set of differential equations - that use genotypic information to produce a phenotype and then map this phenotype to a fitness value.  We are using such a simulation framework to study how genetic networks evolve under different demographic situations.  Experience with C++ would be very useful for this project since the basic population genetic framework consists of a library of C++ templates.