Temperature-Dependent Evolutionary Speed Shapes the Evolution of Biodiversity Patterns Across Tetrapod Radiations

Area of Science:

• Macroevolutionary biology
• Eco-evolutionary dynamics
• Biogeography

Background:

• Global biodiversity patterns are linked to environmental energy, but the underlying evolutionary mechanisms are not fully understood.
• The evolutionary speed hypothesis posits that environmental kinetic energy influences speciation rates via temperature or life history.
• Testing this hypothesis requires integrating ecological and evolutionary processes over geological timescales.

Purpose of the Study:

• To test whether evolutionary speed, specifically temperature-dependent speciation, explains the relationship between environmental energy and biodiversity.
• To investigate the roles of temperature and life history in shaping macroevolutionary diversification.
• To compare process-based simulation modeling with statistical inference for understanding biodiversity patterns.

Main Methods:

• Developed a spatially explicit eco-evolutionary simulation model to simulate tetrapod diversification over 65 million years.
• Modeled four scenarios: speciation rates dependent on temperature (M1), life history (M2), both (M3), or neither (M0).
• Employed supervised machine learning for model selection to compare simulated data with empirical biodiversity patterns.

Main Results:

• The model with temperature-dependent speciation rates (M1) showed the strongest support across multidimensional biodiversity patterns.
• Process-based modeling revealed a significant role for temperature in driving speciation, contrasting with some statistical findings.
• Environmental energy, particularly temperature, is demonstrated as a fundamental driver of biodiversity evolution over deep time.

Conclusions:

• Temperature-dependent evolutionary rates are a key mechanism explaining the link between environmental energy and global biodiversity.
• Eco-evolutionary simulation models provide powerful insights into macroevolutionary processes that may be missed by statistical analyses alone.
• Environmental energy has played a critical role in shaping the diversification of life throughout Earth's history.