Paddles, Proteins, and the Dawn of Photosynthesis

Researchers study ancient cyanobacteria, especially Gloeobacteria such as Anthocerotibacter panamensis, to glimpse how oxygen-producing photosynthesis evolved. A. panamensis has a paddle-shaped antenna and lacks thylakoids, while its photosystem core remains highly conserved, suggesting core machinery persisted while light-harvesting structures diversified; finding more early-branching species could reveal whether oxygenic photosynthesis arose once or multiple times and which photosystem came first.