Phenotyping in Evo-Devo

Abstract

The description and comparison of morphological features has been an integral part of evolutionary developmental biology (evo-devo) from the early comparative embryology in the late nineteenth century to the revival of the discipline in the late twentieth century. The success of modern evo-devo research was fueled by an exciting accumulation of experimental data revealing central mechanisms underlying developmental processes in a few well-established model organisms. Recent advances in imaging and sequencing technologies allow for an in-depth genome-wide and highly quantitative comparison of developmental processes in a variety of organisms. The combination of this quantitative data with the establishment of theoretical and mathematical frameworks to integrate and analyze such data provides an excellent starting point to reveal the evolutionary, genetic, developmental, and ecological forces underlying the morphological diversification in Nature. In this chapter, I summarize key features of qualitative and quantitative phenotyping methods, highlighting advantages and potential limitations. Additionally, I argue that gene expression represents an intermediate phenotype that has the potential to link genotypic and epigenetic changes with the evolution of developmental processes and thus adult morphology.