Internal Factors in Evolution: The Morphogenetic Tree, Developmental Bias, and Some Thoughts on the Conceptual Structure of Evo-devo

Abstract

This chapter argues that the causal structure of development influences the way in which evolution occurs. There are two broad types of influence, one involving variation in the probability of generating developmental variants, the other involving the probability of such variants being selectively advantageous. The chapter concludes with a section on the conceptual structure of Evo-devo. Here, the main argument is that an integrated approach should be taken in which the relationships among different Evo-devo concepts is made clear. I suggest that “developmental repatterning” is an appropriate umbrella term to include different, more specific, types of evolutionary change in development, such as heterochrony and heterotopy.