Evolution and Developmental Programmes

Abstract

We shall never fully understand the process of evolution until we know how the environment affects the mechanisms that produce pattern and form in embryo-genesis. Natural selection must act on the developmental programmes to effect change. We require, therefore a morphoglogical view of evolution, which goes beyond the traditional level of observation to a morphological explanation of the observed diversity. Later in this chapter we shall discuss some specific examples whereby morphogenesis has been experimentally influenced to produce early embryonic forms; early, that is, from an evolutionary point of view. This chapter has no mathematics per se and is more or less a stand-alone biological chapter. However, the concepts developed and their practical applications are firmly based on the models, and their analysis, presented and elaborated in earlier chapters, particularly Chapters 14 and 17.