Development commonly involves substantial material change. Living systems undergo material turnover, growth, differentiation, repair, and reorganisation, sometimes while retaining a biologically relevant continuity across those transformations.
Material sameness and developmental continuity are therefore distinct. Where continuity is maintained, it need not consist in preservation of identical matter or an unchanged structure.
APS treats the relation between material change and organisational continuity as an explanatory question. Establishing developmental continuity requires identifying what relevant organisation persists or is re-established and which processes and dependencies support that continuity through transformation.
Those dependencies should not be assumed in advance. Developmental processes can contribute to continuity, redirection, disruption, recovery, or loss, depending on the biological case and conditions concerned.
Development is therefore not the construction or preservation of a fixed material object. It involves biological transformation through time, within which questions of continuity and identity can be investigated without equating them with material sameness.
Key point: where developmental identity persists across material change, its continuity depends on relevant organisation rather than identical material composition; the basis of that continuity must be established for the case concerned.