Variation and Selection are the two core processes of Dar-winian Evolution. Yet, both are directly regulated by many processes that are themselves products of evolution. Microorganisms efficiently exploit this ability to dynamically adapt to new conditions. Thus, evolution seems to have optimised their own ability to evolve, as a primary mean to react to environmental changes. We call this process Evolution of Evolution (EvoEvo). In this paper, we propose to use an integrated evolutionary model including complex and evolvable genotype-to-phenotype mapping to study EvoEvo. As exemplified in this paper, the integrated evolutionary model will allow us to decipher the EvoEvo strategies and to offer new hypothesis and predictions on the evolution of microorganisms.