This study puts forward two complementary evolutionary models and explores the potential of the proposed models and the related theses by employing two case studies. The theoretical/conceptual framework of the study refers to architectural theory, design research, and evolutionary epistemology. The study mainly involves application of some key ideas from evolutionary epistemology, Popper&amp / #8217 / s three-world ontology, and the theory of evolution to the field of architecture. The first model is about the nature of the architectural ideas or thought contents and it introduces the idea of conceptual inheritance and an evolutionary conception of architectural ideas. The model proposes a framework that offers an understanding of the life and existence of architectural ideas and their inheritance. It also puts forward an expanded view of architectural ideas that conceives all the thought contents, which architectural designs (or works) and the architectural design process might concern, as architectural ideas. In order to illustrate and discuss the model, some of the architectural ideas carried by Mario Botta&amp / #8217 / s single-family house in Breganzona are selected and the evolutionary lineage of these ideas have been identified and examined in their instances in some of Botta&amp / #8217 / s own designs and in some designs from architectural tradition. The second model is an evolutionary model of the architectural design process. While emphasizing the evolutionary or selectionist character of architectural design in terms of process and inner dynamics, the model conceives architectural design as a process consisting of the two stages of forming/making, and evaluation/selection where in the first stage formative ideas, in the second, selective conditions are operational. In order to illustrate the potentialities of the model, the sketches and the drawings produced during the design process of Mario Botta&amp / #8217 / s single-family house in Breganzona are examined.