multi-level selection

Compiled with AI assistance and selectively reviewed. Please consult the cited passages; the books remain the authoritative source. About this companion

Editorial synthesis · provisional

Definition

Multi-level selection is the consideration of differential evolutionary persistence and reproduction at more than one organizational level, including genes, organisms, groups and species. RB1 uses it to complicate a single privileged selection unit. The framework allows interests or outcomes at different levels to diverge; it does not make every ecological collective a selection unit or imply that organized cooperation always benefits each constituent equally.

Explanation

RB1’s table locates the account among evolutionary schools and names several proponents. Its later species-selection discussion concerns characteristics associated with survival and speciation at that level, which need not be identical to traits improving an individual organism’s success. Distinct units and processes must therefore be identified rather than inferred solely from the existence of nested parts.

RB2 supplies a concrete conflict through multicellularity: what advantages one cell can harm the organism of which it is a part. Developmental regulation, cooperation and cell death help sustain the higher-order individual. This illustrates altered constraints on fitness without turning every influence of a whole on its parts into selection by definition.

The holobiont discussion preserves a further qualification. Partner fidelity and collective organization matter to whether a host–microbe association can count as a selection unit; many remain better understood as communities. Multi-level explanation thus broadens the field of inquiry without granting automatic evolutionary individuality to every useful association.

Scope and attribution

Retain the plurality of units with conditions for higher-order individuality and selection.

RB1 — The Real Book, Volume I: The Possible Is Real

Selection levels and conditional holobiont status retain separate criteria.

Occurrence locators: 150, 151, 153, 154, 175.

RB2 — The Real Book, Volume II: Becoming Is Being

The cell–organism conflict illustrates distinct fitness consequences across levels.

Occurrence locators: 270.

Background used in the editorial explanation

Named theories and mechanisms are distinguished from neighboring background, homonyms and the author’s own synthesis. Reproduced AI passages retain their separate voice.