Software ontogeny refers to the ability of software to evolve dynamically in an autonomous way to meet the user needs and the anticipated and unanticipated changes of requirements. The evolution of an ontogenetic system has the particularity to be a continuous process that shapes them from the beginning of their creation. This feature does not match the current development methods, which consider that evolution is a sporadic process. Consequently, the platforms, tools and methodologies we use to develop software systems are not suitable and a huge amount of work is needed to adapt them to support the software ontogeny. In this paper, we propose a combination of three requirement engineering approaches: futures wheel method, goal-oriented requirement engineering and change cases, along with an extension of the rational unified process (RUP) order to modelling and handling anticipated changes in the hypothetical context of ontogenetic systems.