Plate Tectonic History and Ocean Oxygenation Shaping Biogeography of Hydrothermal Bacterial Community

Plate tectonics has fundamentally shaped the biogeography and evolution of macroscopic life, but its influence on microbial distributions remains poorly understood. Here, we demonstrate that the global biogeography of hydrothermal vent-endemic microbiota —specifically, lithoautotrophic bacterial families within the phyla Campylobacterota, Aquificota, and Thermosulfidibacterota (collectively CAT families) — is structured by tectonic history. CAT families, particularly obligate anaerobes, are significantly more abundant in early-origin Pacific, Arctic, and Mediterranean oceans, whereas they are notably scarce in late-formed Atlantic and Indian Oceans. We attribute this pattern to the timing of ocean formation and its interplay with global redox evolution. During the genesis of the former three oceans, anoxic conditions facilitated the unrestricted dispersal among oceans and colonization of anaerobic CAT families in hydrothermal vents. In contrast, fully oxygenated conditions during the formation of the two later oceans imposed a dual barrier: molecular oxygen was toxic to obligate anaerobes, and the oxidation of reduced chemicals depleted the energy sources necessary for facultative aerobes. Our findings established that plate tectonics has imposed first-order constraints on microbial biogeography through long-term modulation of ocean chemistry and habitat connectivity. These results integrate microbial dispersal into a geodynamic framework, revealing that even microbial life is subject to planetary-scale geological constraints.