A solvable senescence model showing a mortality plateau

TL;DR

This paper analytically demonstrates a mortality plateau in a generalized senescence model, highlighting the importance of variable mortality factors like environmental effects in explaining observed aging patterns.

Contribution

It introduces an analytically solvable model of senescence that accounts for variable mortality, explaining the mortality plateau phenomenon.

Findings

Mortality plateau observed late in life in the model.

Variable mortality factors are crucial for realistic aging models.

Analytic solutions provide new insights into senescence dynamics.

Abstract

We present some analytic results for the steady states of the Penna model of sen escence, generalised to allow genetically identical individuals to die at differ ent ages via an arbitrary survival function. Modelling this with a Fermi functio n (of modest width) we obtain a clear mortality plateau late in life: something that has so far eluded explanation within such mutation accumulation models. This suggests that factors causing variable mortality withi n genetically identical subpopulations, which include environmental effects, may be essential to understanding the mortality plateau seen in many real species.