Approaches to Macroevolution: 2. Sorting of Variation, Some Overarching Issues, and General Conclusions.

Area of Science:

• Evolutionary biology
• Macroevolutionary theory

Background:

• Macroevolutionary approaches require integrating variation and sorting within a hierarchical framework.
• Species sorting, or species selection, involves differential origination and extinction rates driven by intrinsic biological properties.

Purpose of the Study:

• To discuss sorting within an evolutionary hierarchy, distinguishing between strict-sense species selection and effect macroevolution.
• To explore how macroevolutionary tradeoffs, intrinsic traits, and extrinsic events influence clade diversification and evolutionary trends.

Main Methods:

• Operationalizing emergence to rigorously separate species-level and organism-level trait influences.
• Analyzing macroevolutionary tradeoffs and their impact on speciation and extinction rates.
• Examining diversity-disparity analyses to understand relationships between taxonomic richness, disparity, and functional variety.

Main Results:

• Species sorting can be divided into strict-sense species selection (species-level traits) and effect macroevolution (organism-level traits), both influencing trait proliferation or decline.
• Macroevolutionary tradeoffs cause covariation in speciation and extinction rates, leading to varied clade diversification dynamics.
• Diversity-disparity analysis reveals complex temporal relationships between taxonomic diversification and morphological/functional disparity.

Conclusions:

• Integrating variation-generating mechanisms with multilevel sorting processes is crucial for advancing macroevolutionary understanding.
• Disentangling the effects of intrinsic traits and extrinsic events on clade dynamics remains a significant challenge.
• Bridging paleontological and neontological approaches is essential for a comprehensive view of historical biology.