Much of the life on earth depends on photosynthesis, a process in which electromagnetic solar energy is used to produce oxygen and carbohydrates from atmospheric CO₂ and water. In plants and algae, the photosynthetic reactions are catalyzed by a system that includes several protein-pigment complexes embedded in the thylakoid membranes. These membranes consist of flattened vesicles that exist either as appressed or single nonappressed membranes. In eukaryotic organisms, the biogenesis and activity of the photosynthetic complexes depends on the coordinate action of the nuclear and chloroplast genetic systems. A remarkable feature of the photosynthetic system is its ability to adapt rapidly to changes in environmental cues, such as light. This essay provides a historical outline of some of the key findings obtained through genetic approaches that had a strong impact on the current understanding of the biogenesis and dynamics of the photosynthetic machinery. It is not possible to cover all the important studies in this area within this short article, and the citations chosen reflect my personal bias. Most of the article bears on the system that catalyzes the primary light reactions and electron transfer in the photosynthetic membranes.