Evolution in APS is not explained by a single privileged mechanism such as natural selection, nor by treating evolutionary change as a simple combination of independent processes.
Evolutionary explanation may instead require several distinguishable explanatory roles:
- Persistence concerns the continuation of viable biological organisation.
- Inheritance concerns the reliable reconstitution of organisation across generations.
- Variation concerns the generation and presence of biological differences within inherited continuity.
- Adaptation concerns continuity-preserving reorganisation under changing conditions and may contribute to evolutionary outcomes.
- Fitness concerns differential historical continuity among lineages or forms of persistence-sustaining organisation.
- Natural selection concerns differential historical stabilisation.
APS places these concepts within a common evolutionary explanatory architecture, but their placement together does not establish a single causal pathway, temporal sequence, necessary dependency chain, or universally fixed biological process.
Some evolutionary explananda may require relations among several of these processes or conditions. The type and evidential status of each relation must, however, be established independently. Architectural or expository ordering is not itself evidence of causal priority, temporal succession, or biological necessity.
Evolutionary transformation is therefore not reducible to one privileged mechanism. It concerns historical transformation of organised persistence across generations, for which different processes and relations may make explanandum-specific explanatory contributions.
Key Point. Persistence, inheritance, variation, adaptation, fitness, and natural selection occupy distinguishable roles within evolutionary explanation. Their organisation within APS provides an explanatory architecture, not evidence of a universal causal or temporal sequence.