The Latitudinal Diversity Gradient: Novel Understanding through Mechanistic Eco-evolutionary Models

Area of Science:

• Ecology
• Evolutionary Biology
• Biodiversity Science

Background:

• The latitudinal diversity gradient (LDG) is a fundamental pattern in ecology, but its causes lack scientific consensus.
• Existing hypotheses are often verbal, hindering mechanistic understanding and empirical testing.
• Multiple explanations frequently align with observed patterns, complicating causal inference.

Purpose of the Study:

• To synthesize and critically evaluate existing hypotheses on the causes of the latitudinal diversity gradient (LDG).
• To develop a mechanistic framework linking ecological and evolutionary processes to the LDG.
• To propose novel modeling and inferential approaches for assessing the relative importance of different drivers of the LDG.

Main Methods:

• Literature synthesis of current LDG hypotheses, focusing on eco-evolutionary mechanisms and assumptions.
• Development of mechanistic eco-evolutionary models to simulate biodiversity patterns.
• Application of an inferential framework utilizing geographic, phylogenetic, and trait data.

Main Results:

• Identified commonalities and hidden assumptions across diverse LDG hypotheses.
• Demonstrated the utility of mechanistic modeling in exploring eco-evolutionary dynamics.
• Showcased how integrated data can disentangle multiple potential drivers of the LDG.

Conclusions:

• A mechanistic, eco-evolutionary approach is crucial for resolving the causes of the latitudinal diversity gradient (LDG).
• Integrated modeling and empirical data analysis provide a robust framework for advancing LDG research.
• Future research should focus on quantitatively testing specific eco-evolutionary mechanisms driving biodiversity patterns across latitudes.