Global physiography dynamics controled the Phanerozoic diversification of the biosphere

 

The contrasted diversification of marine and terrestrial life remains enigmatic. The monotonic expansion of species on continents started later in the early Phanerozoic than in the marine realm, where instead the number of genera waxed and waned. Only a comprehensive evaluation of the changes in the physical environment can provide a unified theory for the long-term pattern of evolution of life on Earth. We developed a numerical model to reconstruct the evolution of the physiography at global scale and high resolution over the entire Phanerozoic eon, accounting for plate tectonics and climatic forcings.

Our results point at landscape dynamics as a limiting factor both in lands and oceans, mostly by erosion and sediment transport. Marine diversity was strongly limited by the oscillating bulk riverine sedimentary fluxes that provide nutrients, while the expansion of land plants was hampered until widespread endorheic basins resurfaced continents with a sedimentary cover that facilitated the development of soil-dependent rooted plants. In both realms, landscape dynamics determine the carrying capacity of the environment.