Book contents
- Evolutionary Physiology of Algae and Aquatic Plants
- Evolutionary Physiology of Algae and Aquatic Plants
- Copyright page
- Contents
- Contributors
- Preface
- Acknowledgments
- 1 Environmental Changes Impacting on, and Caused by, the Evolution of Photosynthetic Organisms
- Part I Origins and Consequences of Early Photosynthetic Organisms
- Part II Physiology of Photosynthetic Autotrophs in Present-Day Environments
- Part III The Future
- Index
- References
1 - Environmental Changes Impacting on, and Caused by, the Evolution of Photosynthetic Organisms
Published online by Cambridge University Press: 24 October 2024
- Evolutionary Physiology of Algae and Aquatic Plants
- Evolutionary Physiology of Algae and Aquatic Plants
- Copyright page
- Contents
- Contributors
- Preface
- Acknowledgments
- 1 Environmental Changes Impacting on, and Caused by, the Evolution of Photosynthetic Organisms
- Part I Origins and Consequences of Early Photosynthetic Organisms
- Part II Physiology of Photosynthetic Autotrophs in Present-Day Environments
- Part III The Future
- Index
- References
Summary
The origin of life could have involved autotrophy, but this is most probably chemolithotrophic rather than photolithotrophic. There is evidence, from the natural abundance of carbon isotopes, of autotrophy involving Rubisco and the Benson–Calvin–Bassham cycle from about 4 Ga. However, other autotrophic CO2 fixation pathways could also have occurred. Evidence on the evolution of photosynthetic reactions suggests an early origin of the photochemical reaction centre, with the possibility of the occurrence of two photosystems in series (photosystem II plus photosystem I) and the possibility of oxygenic photosynthesis, before the origin of the single photosystem (reaction centre I or reaction centre II) photosynthesis in the multiple clades of anoxygenic photosynthetic bacteria. The origin of photosystem II and photosystem I preceded the origin of cyanobacteria and the subsequent Great Oxidation Event at about 2.4–2.3 Ga. The occurrence of oxygenic photolithotrophy is a necessary, but not sufficient, condition for the occurrence of the Great Oxidation Event and the Neoproterozoic Oxidation Event. There is no consensus on what other factors are involved in initiating the Great Oxidation Event and the Neoproterozoic Oxidation Event.
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- Evolutionary Physiology of Algae and Aquatic Plants , pp. 1 - 18Publisher: Cambridge University PressPrint publication year: 2024