Group-level traits are not units of selection

Area of Science:

• Evolutionary biology
• Philosophy of science

Background:

• The concept of units of selection is central to evolutionary theory.
• Distinguishing between individual and group-level selection is a key debate.

Purpose of the Study:

• To evaluate Smaldino's argument for group-level traits as distinct units of selection.
• To explore the implications of Wimsatt's work on emergence and aggregativity for understanding trait levels.

Main Methods:

• Conceptual analysis of Smaldino's claims regarding replicators and interactors.
• Application of Wimsatt's framework of emergence and aggregativity.

Main Results:

• Group-level traits do not meet the criteria for being distinct replicators or interactors.
• Emergent and aggregative traits can be explanatorily reduced to the individual level.

Conclusions:

• Smaldino's argument for group-level units of selection is not established.
• Evolutionary traits are best understood as reducible to individual-level processes.