Debilitation's aftermath: stochastic process models of mortality.

A stochastic differential equation model is developed to clarify the interaction of debilitation, recuperation, selection, and aging. The model yields various insights about the lingering mortality consequences of disasters such as wars, famines, and epidemics that may weaken the survivors. A key result is that debilitation and selection are interdependent: debilitation that increases population heterogeneity will result in subsequent selection; selection, by altering the distribution of population heterogeneity, will influence the impact of debilitating events.