Plate tectonic history and ocean oxygenation shaping biogeography of hydrothermal bacterial community.

The influence of plate tectonics on microbial distributions remains poorly understood. Here, we demonstrate that the global biogeography of hydrothermal vent-endemic chemoautotrophic microbiota is structured by the tectonic history of the global major oceans. These microbiota, particularly anaerobic ones, are significantly more abundant in early-origin Pacific, Arctic, and Mediterranean oceans, whereas they are notably scarce in late-formed Atlantic and Indian Oceans. This pattern was attributed to the timing of ocean formation and its interplay with global redox evolution. Fully oxygenated conditions in the Phanerozoic during the formation of the latter two oceans imposed a dual-dispersal barrier among oceans: toxicity of molecular oxygen to anaerobes and depletion of energy sources (especially reduced chemicals) for aerobes, but such a barrier didn't exist before the Phanerozoic, when the former three oceans started. These results integrate microbial biogeography into a geodynamic framework, revealing that even microbial life is subject to planetary-scale geological constraints.