Development has a central role in the understanding of the evolution of multi-cellular organisms mainly because it is the process that results in the adult organic form. Therefore, every morphological innovation is also a result of changes in development. However, developmental biology remained at the margin of the modern evolutionary synthesis and development has been treated for a long time as a black-box between genotype and phenotype. Only at the beginning of 1980s, the role of development received more attention, and this resulted in unexpected empirical and theoretical progress. This progress resulted in the emergence of a new research field, evolutionary developmental biology (evo-devo), which has been playing an important role in the construction of a new understanding of the evolution of organic forms. We argue that this field has a central role in a "new evolutionary synthesis", currently under construction, which is committed to a "pluralism of processes", that is, the idea that not only natural selection but also a variety of different mechanisms play causal and explanatory roles in biological evolution. We discuss some classical dichotomies in evolutionary thought, particularly between structuralism and functionalism, and transformational and variational processes, in an effort to situate evo-devo in contemporary evolutionary thought.
Evolutionary developmental biology; Evo-devo; Form; Function; Structuralism; Functionalism; Transformationism; Variationism
