Group selection

Definition

A mode of natural selection that operates on the differential productivity or survival of groups rather than individuals or genes, positing that traits disadvantageous to individuals may persist or spread if they confer competitive advantage to the collective. Distinguished from kin selection (selection on genetic relatives) and multilevel selection (partitioned variance components), group selection remains contentious in evolutionary theory, with most apparent cases explicable by inclusive fitness or ecological sorting. In arthropods, the concept has been invoked to explain sterile castes in social insects, though such traits are now generally attributed to kin selection or multilevel selection frameworks.

Etymology

Example

Early explanations for the evolution of suicidal defense by honey bee workers (stinging intruders, which kills the individual) appealed to group selection: colonies with more altruistic defenders might outcompete rival colonies, even though individual workers died. Modern analyses attribute this behavior to kin selection, as workers are more closely related to sisters than to potential offspring.

Synonyms

• interdemic selection
• trait-group selection

Related Terms

• Kin selection
• multilevel selection
• inclusive fitness
• Altruism
• social insect

Usage Notes

The term carries significant historical baggage; many evolutionary biologists avoid it in favor of "multilevel selection" or reframe phenomena within inclusive fitness theory. When used, it should specify whether the mechanism is modeled as differential extinction/founding of groups (classic Wynne-Edwards formulation) or as variance partitioning (Price equation approaches). Contrast carefully with "kin selection"—the two are mathematically equivalent under many conditions but imply different causal emphases. Not synonymous with "group living" or "cooperation."