Scientists at the University of Sydney have advanced a compelling theory about how Earth’s landscapes have shaped life’s diversity over the last 540 million years. This work links the sweeping changes in continents and landforms to the thriving variety of plants and animals we see in the fossil and modern records. The ideas appear in a peer‑reviewed science publication that emphasizes the long arc of Earth’s surface as a driver of biology.
A team of researchers built a detailed computer model to simulate the joint effects of climate change and tectonic plate movement across hundreds of millions of years. They then compared the simulation outputs with independent data on land and marine biodiversity to test how well the model matched the real history of life on Earth. The comparison revealed patterns that connect the pace of geological evolution with shifts in living communities over deep time.
The modeling shows a clear link between the quantity of sediment carried by rivers into the oceans and the richness of marine life. When rivers discharge more sediments, nutrients such as carbon, nitrogen and phosphorus are delivered more broadly to marine environments, fueling primary production and supporting a wider array of species. Conversely, when sediment flux drops, nutrient delivery wanes and diversity tends to decline, highlighting how the mineral and organic inputs from land help sustain oceanic ecosystems.
Another key finding is the relationship between coastal erosion, sediment transport and mass extinction events in Earth’s history. The researchers observe that notable reductions in sediment flow often coincide with periods of marine biodiversity loss. This suggests that nutrient deficits can destabilize entire marine communities and heighten their vulnerability to catastrophic disturbances, including asteroid impacts or major volcanic episodes, by stressing the food web at its base.
Across continental landscapes, the simulations indicate a similar association between sediment availability and plant diversity. When soils accumulate more nutrients and become thicker due to prolonged weathering and sediment deposition, plant communities can develop more complex root systems and greater structural variety. That added complexity appears to enable a broader spectrum of species to occupy terrestrial niches, contributing to the overall richness of life on land.
As plants spread into new regions, they create a mosaic of environments that fosters further evolutionary experimentation. The emergence of flowering plants roughly 100 million years ago, for example, opened new ecological opportunities and helped shape ecosystems in ways that supported multiple lineages of insects, vertebrates and other organisms. The broadening tapestry of habitats amplified ecological interactions and accelerated diversification across many groups.
Across the globe, the researchers conclude that the diversity of life is strongly tied to how the surface of the planet evolves. The tempo of this evolution aligns with the movement of tectonic plates, a process that unfolds over deep time and operates on timescales far slower than human civilization’s current footprint. In contrast, the rapid changes driven by modern human activity are producing unprecedented pressures that outpace natural geological rates and push many species toward extinction faster than any comparable ancient episode.
In the broader scientific conversation, the study adds to a growing view that Earth’s physical dynamics—landforms, soils, oceans and climate—are deeply interconnected with the life they support. By reconstructing long histories of sediment flux, nutrient cycling and habitat shifts, researchers aim to illuminate the pathways through which life responds to planetary change and to clarify how future environmental pressures might unfold in the living world. This perspective emphasizes the planet as an integrated system where geology and biology co‑evolve in a constant, sometimes rapid, dance that tests the resilience of ecosystems across oceans and continents, today and in the deep past. A new global pattern is emerging that redefines how the marine environment is understood in the context of evolving ocean chemistry and nutrient dynamics, and it invites continued exploration into the forces that sculpt biodiversity across time. .