Population genetics and developmental genetics represent two prominent approaches of modern evolutionary research. Within the field of evolutionary developmental biology (EvoDevo), the evolutionary developmental genetics approach gained importance due to the progress in cloning and visualization techniques. Today a fusion of classical population genetic and developmental genetic data seems both challenging and necessary. On the way towards synthetic interpretations and evaluations of evolutionary scenarios there is a need for model systems that are well investigated in both regards. The bodyplans of higher Crustacea (Malacostraca) may represent such a model system. I introduce a number of hypotheses that implicate complex mating systems and their population genetic consequences as key factors in the evolution of Malacostracan bodyplans. Sexual selection, in particular, is assumed to act directly on the expression patterns of developmental regulatory genes underlying the morphology of structures that are crucial for the mating behavior. The main part of this work is the detailed investigation of the complex mating system of Dikerogammarus villosus (Amphipoda), using modern and innovative techniques, such as x-ray microCT, for acquiring morphometric data. Based on the combination of morphometric and regulatory gene expression data, this study may yield new insights into the mechanisms of Malacostracan bodyplan and appendage evolution.
Stephan Handschuh studied zoology at the University of Vienna, focusing on theoretical evolutionary biology, morphology, and imaging methods. He currently works on his doctoral thesis at the University of Vienna, where he also lectures on three-dimensional imaging and visualization methods and histology.