How rising mountains give birth to new species

A new study shows that the forces creating mountain ranges can also drive species diversity, illuminating how Earth’s geological processes shape the evolution of life. 

The work marks a breakthrough in understanding why mountainous areas are hotbeds of species diversity and how tectonic activities may have guided the evolutionary paths of certain groups of organisms over millions of years. The study was co-authored by researchers at Indiana University (IU).

Rising mountains and new species

Long recognized as biological treasure troves, mountain regions often hold surprising numbers of plant and animal species. Yet, it has been difficult to tease out whether high biodiversity naturally accompanies the rugged terrain or if mountains’ geological formation directly promotes new evolutionary processes.

According to this new study, the mere act of mountains rising can create conditions that give birth to new species. Shifting landscapes open up new habitats and geographically isolate populations, encouraging the emergence of new, distinct species – a process known as allopatric speciation. 

Among smaller animals such as rodents, the team found a strong correlation between how quickly and how high mountains lift up and the degree of species diversification.

A closer look with virtual worlds

The research team, which includes Eyal Marder of the University of Massachusetts Amherst (a former IU postdoctoral fellow) and Brian Yanites, an associate professor of Earth and Atmospheric Sciences at IU, used advanced computer models to simulate how species might evolve in response to rising terrain over very long timescales.

They based their work on “Adascape,” a specialized model that allows for virtual representations of the Earth’s surface and how it changes. Then, they coupled it with programs that populate these landscapes with model species and track how they adapt and migrate as mountains slowly take shape. 

The result was a synthetic view of how evolution might proceed in response to upheavals that can last tens of millions of years.

One of the more compelling revelations from these simulations is that certain mountainous areas can act like “cradles” of new biodiversity. A species of rodent-like mammals in the model, for instance, split into multiple distinct species as soon as the mountains rose and created different environmental niches. 

Over time, some of these new species even migrated into adjacent lowlands, matching patterns paleontologists often see in fossil deposits.

Connecting to the fossil record

Past geologic intervals have left behind a record of biodiversity booms that, until now, were not well explained. The authors propose that at least some of these booms may correlate with upticks in tectonic activity. 

For example, the researchers suggest that a known spike in fossil diversity about 15 million years ago in the western United States might be linked to local mountain building in the Basin and Range region, which shaped both animal evolution and the formation of sedimentary basins.

“This study gives us new insights into how Earth’s physical processes influence the diversity of life,” Marder said. “It also highlights how ongoing geological changes could continue to impact biodiversity in the future.”

The hidden role of mountains

Previous theories had proposed that mountains simply serve as a stage on which evolution plays out. In contrast, this research indicates that landscapes in flux can actively spark or redirect the evolutionary process. 

“We often think of landscapes as passive backdrops for evolution, but this study shows that they are active participants in shaping biodiversity,” Yanites said.

Mountain-building pushes populations up or isolates them in valleys, subjecting organisms to different climates, food sources, and environmental pressures. 

Over time, these constraints spawn new species. The link between tectonics and evolution grows even stronger when one considers that mountain ridges can capture moisture and alter local climates, further driving organisms to adapt or relocate.

Implications for conservation

Beyond helping explain the past, these findings may also help conservationists decide how and where to protect species. Mountains remain sensitive to climate change; as conditions shift, those living at high elevations may have nowhere left to migrate. 

Understanding which areas are most critical for speciation could focus conservation efforts on safeguarding genetic diversity hotspots.

By revealing how rising mountains foster new species, this study may also guide reevaluation of existing protected zones. If certain ridge systems are particularly crucial for generating biodiversity, setting them aside or expanding current reserves might become a priority. 

This knowledge could likewise apply to other dynamic environments – like tectonically active rifts or volcanic zones – which might also harbor outsized roles in biological innovation.

Mountain uplift and species evolution

Moving forward, the authors aim to extend their computer modeling to different regions and sets of organisms, matching simulated results more closely with fossil records and genetic data. This interdisciplinary approach can refine projections about how topography influences evolution today and in the future.

According to the scientists, it’s not just about where species are now but about how a place changed over time, and how that might have sparked speciation or extinctions. This link between landscapes and life is something we’re just beginning to fully appreciate.

By establishing a clear, data-driven link between tectonic uplift and the evolution of new species, the study offers a novel perspective on Earth’s living tapestry – and on the power of the planet’s deep geological machinery to shape life across the ages.

The study is published in the journal Science. 

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