Deep beneath the Earth’s surface, where molten rock surges and tectonic plates shift over unimaginable spans of time, forces at work have shaped not just continents, but the very course of life on our planet. Recent research published in Nature Reviews Earth & Environment has illuminated a remarkable geological saga: a plume of hot mantle rock that propelled itself upward millions of years ago was a crucial agent in sculpting a land bridge connecting Asia and Africa. This geological event fundamentally altered the pathways for the migration of land animals, including the primordial ancestors of elephants, giraffes, and even humans.
The significance of this mantle plume extends far beyond its fiery origins. By driving the gradual uplift of regions spanning what we now recognize as the Arabian Peninsula and Anatolia, this phenomenon helped terminate a prolonged period—lasting approximately 75 million years—during which Africa remained geographically isolated from Eurasia. This isolation had profound consequences, constraining evolutionary pathways and climatic development on the African continent. The land bridge’s emergence, facilitated by a complex interplay of mantle convection and tectonic collisions, was instrumental in enabling intercontinental faunal exchanges.
Researchers from the University of Texas at Austin’s Jackson School of Geosciences, alongside contributions from the GFZ Helmholtz Centre for Geosciences, combined new geodynamic modeling with a broad synthesis of existing research to unravel the mechanisms behind this transformative uplift. Their work demonstrates that beneath the apparent rigidity of tectonic plates lies a dynamic mantle “conveyor belt,” whereby a segment of the subducting slab tens of millions of years ago instigated convective currents that transported anomalously hot rock upward. These mantle plumes exerted dynamic topographical forces on Earth’s crust, producing gradual but persistent uplift over millions of years.
Around 50 to 60 million years ago, the process began with the subduction of oceanic crust slabs diving into the mantle. The descending slab’s weight triggered mantle flow patterns that funneled heat and buoyant rock upward. After several decades of geological time, these upwelling mantle plumes initiated surface uplift roughly 30 million years ago. This uplift gradually raised landmasses, closing off the ancient expanse of the Tethys Sea and splitting it into the Mediterranean and Arabian Seas. Ultimately, this process connected two vast continents for the first time in tens of millions of years.
The implications of this land bridge reach deep into the annals of evolutionary history. The emergence of terrestrial corridors linking Asia and Africa rewrote migration narratives. Species previously confined to isolated landmasses could now traverse new environments, fostering gene flow and sparking diverse evolutionary trajectories. In particular, the migration of early mammalian fauna such as primitive elephants, cheetahs, rhinoceroses, and giraffes was directly linked to the topographical changes wrought by mantle dynamics.
Eivind Straume, the study’s lead author, who conducted the analyses as a postdoctoral fellow at the Jackson School and is now affiliated with the Norwegian Research Centre and The Bjerknes Centre for Climate Research, emphasized the transformative impact of mantle convection on biogeography. His models revealed that the shallow seaway separating Africa and Asia, which was destined to close in due course due to ongoing tectonic collisions, was accelerated by the dynamic topography induced by the mantle plume. Without this convective force, the continent’s collision timeline—and consequently animal migration patterns—would have unfolded differently, potentially altering the evolutionary paths of numerous species, including our own ancestors.
Indeed, the timing of these geological events bears considerable weight in understanding human evolution. Primitive primates originating from Asia ventured into Africa several million years before the land bridge fully formed. Although these primates eventually became extinct in Asia, their evolutionary lineages flourished and diversified on the African continent. With the complete closure of the land bridge, these primates reentered Asia, illustrating a complex cadence of migration shaped by geological forces operating far below ground.
Beyond the realm of evolutionary biology, this mantle-driven uplift had profound climatic ramifications. The elevation of the Arabian Peninsula altered atmospheric circulation, impacting ocean temperatures and regional climate regimes. Researchers noted the warming of adjacent ocean waters, coupled with an increased seasonal temperature range on land. This climatic shift contributed to the broad aridification of a vast belt extending from northern Africa through central Asia, an ecological transformation that included the desertification of the Sahara Desert.
Simultaneously, the topographical modifications enhanced monsoon dynamics in Asia, intensifying rainfall patterns over Southeast Asia. This dichotomy in climate—arid conditions in some regions juxtaposed with wetter monsoon seasons in others—showcases the intricate interplay between mantle convection, surface geology, and global atmospheric systems. Such findings underscore the necessity of integrating geophysical processes with climatic and ecological models to comprehend Earth’s evolving environment holistically.
This research cohesively weaves together diverse scientific disciplines, spanning plate tectonics, mantle geodynamics, paleogeography, evolutionary anthropology, mammalian evolution, climate history, and ocean circulation. It advances a paradigm wherein deep Earth processes are not isolated phenomena but integral actors influencing life’s trajectory and planetary habitability. The authors propose that understanding these mantle dynamics is key to answering fundamental questions about Earth’s past, including the intricate relationships that link internal planetary mechanisms with biospheric evolution.
Thorsten Becker, a professor involved with the study at the Jackson School’s Department of Earth and Planetary Sciences and Institute for Geophysics, described the work as both compelling and subtly provocative. By reframing tectonic and mantle processes as drivers of not merely physical change but also biological and climatic transformations, this synthesis challenges conventional boundaries within the earth sciences and invites broader interdisciplinary collaboration.
The study’s revelations ultimately speak to the intimate dialogue between the Earth’s deep interior and its surface biosphere. The mantle plume that once roiled beneath the Tethyan realm sculpted the contours of continents and helped forge the pathways along which life would dramatically unfold. This geological history emphasizes that the planet’s physical evolution is inextricably linked with the rise and diversification of life, offering profound insights into how the dynamic Earth has shaped its own living tapestry over millions of years.
Subject of Research: Not applicable
Article Title: Collision, mantle convection and Tethyan closure in the Eastern Mediterranean
News Publication Date: 1-Apr-2025
Web References: http://dx.doi.org/10.1038/s43017-025-00653-2
References: Straume, E., Becker, T., et al. (2025). Collision, mantle convection and Tethyan closure in the Eastern Mediterranean. Nature Reviews Earth & Environment.
Image Credits: Lisha Steinberger
Keywords
Dynamic topography, Evolutionary processes, Ocean circulation, Land bridges, Earth surface, Tectonic uplift, Human evolution, Mantle slabs, Earth crust, Subduction, Paleoclimatology
