Abstract

Within the field of Evo-Devo, great emphasis has been placed on how the gene regulatory networks that pattern embryos evolve over time. However, these networks do not, by themselves, give rise to the embryonic form that is eventually exposed to natural selection at the larval/adult stage. Rather, this form comes from cell division, rearrangement and shape changes that drive tissue level changes. Therefore, in order to understand how animal form evolves, we must uncover how the changes in gene regulatory networks that we observe actually effect changes at the morphogenetic level. In my seminar, I will first present some of my own work on the morphogenetic basis of development in the beetle Tribolium castaneum. This species is particularly well suited for studying morphogenesis as during early development, extensive cellular rearrangements and tissue folding take place. Furthermore, while these morphogenetic events are conserved in most insects, they do not take place in the fly Drosophila melanogaster. After setting the scene with Tribolium, I will present my most recent work on the morphogenetic function of Toll genes, a project that features findings from seven different species spanning over 500 million years of evolution. Lastly, I will discuss how we can integrate findings on the morphogenetic basis of development into what we already know about the evolution of embryogenesis.