Biological Explanation is the investigation of the organisation through which living systems maintain and re-establish the conditions of their own persistence.
Within APS, explanation is not directed primarily toward isolated mechanisms, individual components, historical sequences, or behavioural outcomes. These may contribute to explanation, but they do not by themselves identify the explanatory target. The central question is how living organisation is established, maintained, modified, and sustained across time.
Biological explanation therefore seeks to understand the organisation that makes living systems possible. This organisation consists in the ongoing modulation of constraints through which living systems actively maintain and re-establish the conditions of their own persistence. The explanatory task is to identify how this organisation is achieved, how it changes, and how increasingly complex forms of organisation emerge from it.
APS approaches this task through the complementary perspectives of Agency, Process, and Scale. Agency identifies the viability-oriented activity through which living organisation is enacted and sustained. Process identifies the dynamic organisation and modulation of constraints through which continuity is maintained despite change. Scale identifies the spatial and temporal extent through which organised persistence is distributed and investigated.
Biological explanation is therefore not restricted to describing what living systems are. It seeks to understand how organised persistence is achieved and how increasingly complex forms of organisation arise from, depend upon, and transform that persistence.
Architectural Dependency contributes to this explanatory programme by investigating the organisational conditions required for different forms of organisation to emerge, operate, persist, or become intelligible. Dependency relations do not replace Agency, Process, and Scale. They provide a methodological framework for reconstructing explanatory architectures within and across biological domains.
Within APS, biological explanation is ultimately concerned with making life scientifically intelligible by identifying the organisation through which living systems maintain and re-establish the conditions of their own persistence.