Conventional framing
In standard biology, development describes the sequence of changes an organism undergoes from fertilisation to maturity, often modelled as a genetically guided program producing a stable adult form, shaped by environmental inputs.
APS reframing
In APS, development is the temporally extended differentiation and reorganisation of biological organisation through which a living system undergoes coordinated change across its developmental history. It is not the linear unfolding of a genetic plan, but an organised process in which molecular, cellular, physiological, morphological, behavioural, and other developmentally relevant processes may be coordinated and reorganised through time.
Development can contribute to organised persistence, viability, repair, adaptation, and other biological outcomes, but these relations are not built into its definition. Their explanatory significance must be established for the biological case and target concerned.
Key Point
Development is the temporally extended differentiation and reorganisation of biological organisation through which living systems undergo coordinated change across their developmental histories.