Increased Network Interdependency Leads to Aging

TL;DR

This paper models aging as a consequence of increasing interdependence in complex networks, showing how damage accumulation and collapse can explain mortality patterns across biological and mechanical systems.

Contribution

It introduces a network-based model of aging that accounts for systemic interdependence and reproduces observed mortality data across diverse organisms and machines.

Findings

Networks gradually accumulate damage leading to collapse.

Simulation results fit experimental mortality data.

Aging emerges as a finite-size network effect.

Abstract

Although species longevity is subject to a diverse range of selective forces, the mortality curves of a wide variety of organisms are rather similar. We argue that aging and its universal characteristics may have evolved by means of a gradual increase in the systemic interdependence between a large collection of biochemical or mechanical components. Modeling the organism as a dependency network which we create using a constructive evolutionary process, we age it by allowing nodes to be broken or repaired according to a probabilistic algorithm that accounts for random failures/repairs and dependencies. Our simulations show that the network slowly accumulates damage and then catastrophically collapses. We use our simulations to fit experimental data for the time dependent mortality rates of a variety of multicellular organisms and even complex machines such as automobiles. Our study suggests that aging is an emergent finite-size effect in networks with dynamical dependencies and that the qualitative and quantitative features of aging are not sensitively dependent on the details of system structure.