Evolution of Photosynthesis

Photosynthesis originated once during the early Archaean due to the emergence of photochemical reaction centres, the biological nanomachines that convert the energy of light into chemical energy. The evolution of the photosynthetic machinery is consistent with a single origin of photosynthesis followed by an early diversification event that resulted in the rapid evolution of distinct reaction centre types and pigment forms. One of these reaction centres specialised in highly oxidising photochemistry, which facilitated the oxidation of Mn and the evolution of the water‐oxidising cluster of Photosystem II. In addition, the last common ancestor of all photosynthetic organisms can be traced back to a period of time near the root or at the root of the tree of life of bacteria, with the current distribution of photosynthesis being the result of widespread loss of photosynthetic capacity and horizontal gene transfer