Before revision:  We show that ageing contains both a stochastic component, related to regulatory error accumulation in transcription/translation/metabolic pathways , and a strong deterministic component, which can be naturally associated with a part of a development programme. We conclude on this basis that two opposing hypotheses of ageing, error accumulation and programmed ageing are in fact compatible with each other.
After revision:  We show that ageing contains both a stochastic component, related to regulatory error accumulation in transcription/translation/metabolic pathways , and a strong deterministic component, suggesting genetic control.