Persistence is often understood as remaining the same through time. In APS, however, persistence has a more precise biological meaning. Living systems persist not because they resist change, but because they continually reorganise themselves in ways that preserve their viability.
Every organism undergoes continuous transformation. Molecules are replaced, cells divide, tissues remodel, behaviours adapt, and environments change. Despite this continual turnover, living systems maintain sufficient organisational continuity to remain recognisably the same organism. Persistence therefore depends upon ongoing biological activity rather than static permanence.
APS consequently interprets persistence as a temporal achievement. Regulation, repair, development, adaptation, and reproduction all contribute to the continual maintenance of organised continuity through time. Change is therefore not the opposite of persistence but one of the means by which persistence is accomplished.
APS Principle: Persistence is not the absence of change. It is the continual organisation of change in ways that preserve viable continuity.