In this short chapter, I draw on the criticisms of the modern consensus offered in Chapters 3 and 4, and so on my account of constitutive epigenetics, to produce a framework for understanding and explaining organismal development. Within this framework, genes play an important role, but as derived rather than driving factors; here, developmental agency is restricted to organisms.

I begin with a brief discussion of the benefits and limitations of developmental biology based on model systems, underscoring the lesson of Chapter 1 that we must be careful in making scientific generalisations on the basis of particular (types of) experiments. I then emphasise again the notion that the organism is the basic unit of development, and I proceed to elaborate my framework for understanding and explaining development in creative terms. In showing how and where this framework differs from the modern consensus, I discuss the dialectics of gene–organism–environment interactions in development, with particular attention to the phenomenon of niche construction.