Global patterns of speciation and diversity.

Area of Science:

• Ecology
• Evolutionary Biology
• Theoretical Biology

Background:

• Consistent patterns of biodiversity observed across diverse ecosystems and taxa.
• Neutral theory, positing no selection or interactions, successfully predicts many biodiversity patterns.
• Existing neutral theory models speciation via mutation in asexual populations.

Purpose of the Study:

• To simulate biodiversity patterns in populations with sexual reproduction, mutation, and dispersal.
• To test the predictive power of neutral theory in a more complex, sexual reproduction model.
• To investigate the emergent properties of biodiversity under simulated evolutionary processes.

Main Methods:

• Agent-based modeling simulating populations with sexual reproduction, mutation, and dispersal.
• Analysis of simulated speciation rates over time.
• Examination of species-area relationships and species abundance distributions in simulated environments.

Main Results:

• Simulated speciation rates exhibit time dependence.
• Species-area relationships show three distinct scaling regimes.
• Species abundance distributions follow lognormal patterns, with an excess of rare species.
• Model predictions align quantitatively with empirical data from various taxa and ecosystems.

Conclusions:

• Biodiversity patterns can arise without specific physical barriers or strong selection pressures.
• Sexual reproduction, mutation, and dispersal are sufficient to generate complex biodiversity patterns.
• The findings support and extend neutral theory's applicability to ecological and evolutionary biodiversity.