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
- 2 Early Photosynthetic Organisms
- 3 …And Nothing Was the Same Anymore: The Rise in O2 and Consequences for Photoautotrophs
- 4 The Appearance of Eukaryotic Microalgae
- 5 The Appearance of Macroalgae: Evolution and Ecological Consequences of Multicellularity
- 6 The Evolution of Aquatic Embryophytes: Secondary Colonisers of Aquatic Environments
- Part II Physiology of Photosynthetic Autotrophs in Present-Day Environments
- Part III The Future
- Index
- References
3 - …And Nothing Was the Same Anymore: The Rise in O2 and Consequences for Photoautotrophs
from Part I - Origins and Consequences of Early 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
- 2 Early Photosynthetic Organisms
- 3 …And Nothing Was the Same Anymore: The Rise in O2 and Consequences for Photoautotrophs
- 4 The Appearance of Eukaryotic Microalgae
- 5 The Appearance of Macroalgae: Evolution and Ecological Consequences of Multicellularity
- 6 The Evolution of Aquatic Embryophytes: Secondary Colonisers of Aquatic Environments
- Part II Physiology of Photosynthetic Autotrophs in Present-Day Environments
- Part III The Future
- Index
- References
Summary
The evolution of oxygenic photosynthesis had profound effects on the biogeochemistry of the planet. The increase in atmospheric oxygen levels brought about alterations to a range of biogeochemical processes involving changes in the availability of a host of elements, including nitrogen, sulfur and many metal ions such as iron and manganese, central to biological activities. Critically for photosynthetic organisms, the increase in oxygen levels in the atmosphere following the evolution of oxygenic photosynthesis and the Great Oxidation Event had consequences for the assimilation of inorganic carbon via the enzyme ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco). Although there are a number of alternative pathways leading to autotrophic CO2 assimilation, 99% of primary productivity on the planet is carried out by processes that involve Rubisco and the Benson–Calvin–Bassham cycle. The accumulation of O2 in the atmosphere also had major repercussions for increasing the energetic yield of the catabolism of photosynthate by allowing oxidative respiration, with a much greater ATP yield than from anaerobic fermentative processes. The interaction of O2 with UVC radiation led to the production of UVC- and UVB-absorbing O3. This also significantly influenced life on Earth and facilitated the colonisation of the upper ocean and terrestrial surface.
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- Evolutionary Physiology of Algae and Aquatic Plants , pp. 43 - 64Publisher: Cambridge University PressPrint publication year: 2024