Author:
Braakman Rogier,Follows Michael J.,Chisholm Sallie W.
Abstract
Metabolism mediates the flow of matter and energy through the biosphere. We examined how metabolic evolution shapes ecosystems by reconstructing it in the globally abundant oceanic phytoplankterProchlorococcus. To understand what drove observed evolutionary patterns, we interpreted them in the context of its population dynamics, growth rate, and light adaptation, and the size and macromolecular and elemental composition of cells. This multilevel view suggests that, over the course of evolution, there was a steady increase inProchlorococcus’ metabolic rate and excretion of organic carbon. We derived a mathematical framework that suggests these adaptations lower the minimal subsistence nutrient concentration of cells, which results in a drawdown of nutrients in oceanic surface waters. This, in turn, increases total ecosystem biomass and promotes the coevolution of all cells in the ecosystem. Additional reconstructions suggest thatProchlorococcusand the dominant cooccurring heterotrophic bacterium SAR11 form a coevolved mutualism that maximizes their collective metabolic rate by recycling organic carbon through complementary excretion and uptake pathways. Moreover, the metabolic codependencies ofProchlorococcusand SAR11 are highly similar to those of chloroplasts and mitochondria within plant cells. These observations lead us to propose a general theory relating metabolic evolution to the self-amplification and self-organization of the biosphere. We discuss the implications of this framework for the evolution of Earth’s biogeochemical cycles and the rise of atmospheric oxygen.
Publisher
Proceedings of the National Academy of Sciences
Reference163 articles.
1. Schrödinger E (1944) What Is Life? The Physical Aspect of the Living Cell (Cambridge Univ Press, Cambridge, UK).
2. Morowitz HJ (1968) Energy Flow in Biology; Biological Organization as a Problem in Thermal Physics (Academic, New York).
3. TOWARD A METABOLIC THEORY OF ECOLOGY
4. The Microbial Engines That Drive Earth's Biogeochemical Cycles
5. The compositional and evolutionary logic of metabolism
Cited by
124 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献