Damage accumulation, repair, and aging

Many mathematical models of aging identify the aging process with the gradual accumulation of some (generally unspecified) damage, and attribute the (partial) failure of some (generally unspecified) repair mechanisms to energetic tradeoffs against growth and reproduction. But the constraints on repair are not simply energetic. New models need to (and some gradually do) focus on the multiple costs and constraints on repair. These include the structural costs of designing for reparability, the cost of finding damage to repair, the cost of overactive repair mechanisms, and the logical impossibility of executing some repairs in the absence of an external template.

A new model of damage distribution in populations of fissioning single-celled organisms helps to clarify the aging process where damage is accumulated not within organisms, but within lines of descent. Here natural selection functions to purge otherwise irreparable damage, a process similar to that which Graham Bell denoted as "exogenous repair".

This presentation is based on work with Steve Evans [1] and Lloyd Goldwasser.

Presentation slides[2]

Papers: General Theory of damage/repair models "Aging and Total Quality Management: Extending the reliability metaphor for aging"[3] (In Evolutionary Ecological Research Dec. 2006)

Damage segregation model "Damage segregation at fissioning may increase growth rates: A superprocess model" [4] (To appear in Theoretical Population Biology)

Generalized Mutation-Selection models "A generalized model of mutation-selection balance with applications to aging" [5]

"A mutation-selection model for general genotypes with recombination" [6]