Understanding how biodiversity unfolds through time under neutral theory

Area of Science:

• Ecology
• Macroecology
• Biodiversity Science

Background:

• Theoretical ecology often assumes systems reach dynamic equilibrium.
• Growing evidence suggests ecological systems, including species richness, are not at equilibrium.
• Understanding biodiversity dynamics requires analyzing patterns over time.

Purpose of the Study:

• To analyze how biodiversity patterns unfold through time using simulations.
• To determine the relative time required for macroecological and phylogenetic patterns to reach equilibrium.
• To test predictions of the Neutral Theory of Biodiversity (NTB) under non-equilibrium conditions.

Main Methods:

• Simulated spatially explicit metacommunities using the Neutral Theory of Biodiversity (NTB).
• Investigated three modes of speciation differing in evenness of individual distribution between daughter species.
• Tracked the stabilization times for species richness, species area relationships (SAR), and species abundance distributions (SAD).

Main Results:

• Species richness was the first pattern to stabilize, followed by SAR, and then SAD.
• The disparity in stabilization times increased with unevenness in individual distribution during speciation.
• Phylogenetic biodiversity patterns required significantly longer to stabilize (hundreds of times longer than species richness).

Conclusions:

• Biodiversity patterns do not necessarily reach equilibrium simultaneously.
• Equilibrium-based predictions from neutral theory may not apply to phylogenetic patterns.
• Assuming ecological equilibrium may be inappropriate; studying temporal dynamics is crucial.