Molecular evidence for the evolution of photosynthesis

Photosynthesis is a complex metabolic process that originated on the early Earth, Recently reported evidence based on the molecular evolutionary analysis of the chlorophyll biosynthetic pathway suggests that the photosystem in the anoxygenic purple photosynthetic bacteria is the most ancient known, and that the photosynthetic apparatus in the oxygen-evolving cyanobacteria and relatives was the most recent to appear. This and other evidence indicate that photosynthesis has had a complex and nonlinear evolutionary history and that different parts of the photosynthetic apparatus have distinct evolutionary origins.