In this paper, we use the Meaning Generator System (MGS) presented at Gathering in Biosemiotics 2  to analyse the evolution of meaningful information generation through different steps of the evolution of life. Taking as a starting point the usage of MGS for vital constraint satisfaction in basic life (paramecium), we develop its application for more complex living elements up to the case of non-human primate. The thread we follow is relative to the identification of new constraints that can appear through evolution of life, and correspondingly participate to generation of new types of meaningful information. We show that beside the complexification of vital constraints to be satisfied, and in addition to the corresponding enrichment of their satisfaction processes, there is a step in evolution that naturally introduces some specific new constraint in living elements. This step is the one corresponding to the performance of self-representation. Self-representation appeared in evolution at the level of non-human primates. We present the content of self-representation and show that it has a direct consequence on the living element in terms of a new type of constraint to be satisfied. We show that this new constraint participates to the generation of a new set of meaningful information via the MGS, and that the satisfaction of the constraint introduces some natural formulation of emotion generation during the evolution of life.