What Taking Development Seriously Means for Evolutionary Theory

Proponents of the Extended Evolutionary Synthesis (EES) emphasize the critical role that organisms and their development play in the process of evolution. This framework explicitly rejects the genocentric focus that once dominated interpretations of the Modern Synthesis in evolutionary theory. In place of genocentrism, EES highlights processes like niche construction, developmental constraint, and extragenetic inheritance as central to any understanding of the evolutionary process. However, much more is at stake in adopting the EES than simply moving beyond the gene-dominant viewpoint of the Modern Synthesis. The EES, in fact, represents a fundamental challenge to the core of classic Darwinism itself by actively repudiating Darwin's key idea that natural selection acts as a creative force in the construction of phenotypes and phenotypic change. In this paper, we more fully explore the assumptive base of Darwinism's population-oriented, selectional focus. We demonstrate how taking development seriously in evolutionary theory mandates a systematic overhaul of Darwinism's assumptive base in favor of grounding all understanding of phenotypic construction in the developmental processes of self-organization endemic to organisms' active engagement with their worlds.