John M. ArchibaldThe evolution of the eukaryotic cell is a puzzle that has challenged biologists for over a century. The prokaryote-eukaryote divide is enormous and many fundamental questions about the origin of eukaryotes and their endosymbiotically derived mitochondria and plastids remain unanswered. Comparative genomics is a powerful tool with which to address such questions. In this talk I will place the modern-day study of cellular evolution in a historical context, highlighting advances and lingering uncertainties in our understanding of the role of endosymbiosis in the evolution of eukaryotic organelles.