SELECTION AMONG "SPECIES": A FORMULATION IN TERMS OF NATURAL FUNCTIONAL UNITS

Area of Science:

• Evolutionary Biology
• Ecology
• Theoretical Biology

Background:

• Traditional species selection lacks a clear causal mechanism for evolutionary change.
• Clades do not meet the criteria for units of selection due to lack of localization and shared environment.
• Higher-level selection requires units analogous to populations in traditional selection theory.

Purpose of the Study:

• To redefine the units of higher-level natural selection.
• To propose a causal mechanism for evolution at levels above the species.
• To reconcile higher-level selection theory with organismic selection.

Main Methods:

• Conceptual analysis of natural selection theory.
• Comparison of clades, communities, and populations as units of selection.
• Development of the "avatar selection" concept.

Main Results:

• Communities, not clades, function as the units of higher-level selection.
• Species populations within communities act as "avatars" undergoing selection.
• Avatar selection provides a mechanism for community and higher-taxon evolution.

Conclusions:

• Communities evolve via avatar selection, analogous to organismic selection.
• This framework aligns higher-level selection with organismic selection.
• Suggests a path for extending selection theory to higher evolutionary levels.