Conventional framing
Adaptation is often understood as the outcome of natural selection, referring to traits that increase fitness in a given environment. In such accounts, adaptation is primarily historical and population-level, identified retrospectively through evolutionary success. This framing can obscure the ongoing, organism-level processes through which living systems actively maintain their viability under changing conditions.
APS reframing
APS defines adaptation as an ongoing, present-tense process grounded in biological agency. Living systems do not simply possess adaptations; they adapt. This activity consists in the continuous reorganisation of constraint-closed organisation in response to perturbation, enabling systems to sustain their persistence through change.
Adaptation occupies the intermediate temporal domain linking persistence and evolution. Persistence names the immediate maintenance of viability, adaptation names the reorganisation that sustains viability under changing conditions, and evolution names the long-term transformation of such organisation across generations.
Adaptive processes are inherently homeorhetic: viability is maintained not as a fixed state but as a trajectory sustained through ongoing reorganisation. Adaptation thus connects short-term regulation with long-term evolutionary transformation without reducing one to the other.
Key Point
Adaptation is the temporal extension of agency—the ongoing reorganisation of constraint-closed organisation that sustains persistence as conditions change.