Diversity partitioning in Phanerozoic benthic marine communities

Area of Science:

• Paleoecology and Evolutionary Biology
• Biodiversity Science
• Marine Invertebrate Paleontology

Background:

• Biotic interactions like competition and predation are key drivers of local biodiversity.
• The long-term impact of these interactions on overall biodiversity across geological timescales is debated.
• Understanding biodiversity limits and drivers is crucial for ecological and evolutionary studies.

Observation:

• Within-habitat (alpha), between-habitat (beta), and overall (gamma) diversity of benthic marine invertebrates were analyzed across Phanerozoic geological formations.
• Data spanned the entire Phanerozoic eon, allowing for long-term trend analysis.
• Specific focus on marine invertebrate fossil record to reconstruct past ecosystems.

Findings:

• Increases in overall (gamma) diversity were consistently driven by increases in within-habitat (alpha) diversity throughout the Phanerozoic.
• Between-habitat (beta) diversity influenced gamma diversity primarily during early diversification stages.
• The coupling between beta and gamma diversity weakened over time, indicating a shift in diversification mechanisms.

Implications:

• The Phanerozoic's biodiversity increases were mainly achieved by adding species to existing local habitats, suggesting ecological saturation was not reached.
• Results support ecological models where diversification progresses through increasing levels of biotic interactions.
• This provides a long-term perspective on biodiversity dynamics and the role of ecological factors in shaping life's history.