APS explains ecological continuity through organism–environment coupling.
Organisms do not persist independently of their environments. Resources, constraints, opportunities, hazards, and ecological conditions all contribute to the maintenance of viability.
For this reason, APS treats organism and environment not as separate explanatory domains but as components of a continuity-preserving organisation.
Persistence depends upon the organisation of the relationship between them.
An organism unable to maintain appropriate ecological relations will lose viability regardless of its internal organisation. Equally, environments become biologically significant only in relation to the organisms that inhabit them.
Opportunities, constraints, resources, and hazards matter because they contribute differently to continuity. Ecological significance therefore emerges through coupling.
Life persists not merely within organisms but through organised organism–environment relations.