This chapter focuses on the co-evolutionary aspects of the generative design process, highlighting the need for specific research into the interdependence between the knowledge types, thinking paradigms, and the design systems under consideration. The chapter argues that, in addition to the co-evolutionary aspects of a design process in general, there are unique co-evolutionary aspects associated with the generative design process. These additional co-evolutionary aspects unique to the generative design process arise from the need to represent the primary design problem in a generative design form and to design and implement a generative design system to support solving the primary design problem. The chapter is based on theoretical arguments, reinforced with evidence from a preliminary set of design experiments conducted using a tangible design kit.