Atmospheric bulk chemistry and evolutionary megasymbiosis

The Paleozoic saw the appearance explosive evolution of the animal, plant, and fungal kingdoms. It was also a time of massive organic carbon burial, dominated by terrestrial sources, leading to major geochemical perturbations. It is argued that these perturbations were the direct consequence of land-ward radiation of plants and fungi, and that the timing of the geochemical perturbations was, at least in part, controlled by the co-evolution of Plantae, as anabolizers of decay-resistent compounds, and Fungi, as catabolizers of decay-resistent compounds. It is speculated that the evolution of analogous megasymbiotic associations between higher taxonomic groupings has played a transcendent, cohesive role in shape and integrating the long-term dynamics of the Earth system.