View source for 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 
[http://www.stat.berkeley.edu/~evans/] and Lloyd  
Goldwasser.

Papers:
General Theory "Aging and Total Quality Management: Extending
the reliability metaphor for aging"[http://www.mast.queensu.ca/~steinsaltz/papers/steinsaltz_goldwasser_repair2.pdf]
(In Evolutionary Ecological Research Dec. 2006)

Damage segregation model "Damage segregation at fissioning may increase growth rates: A superprocess model"
[http://www.mast.queensu.ca/~steinsaltz/papers/damagesuper.pdf]
(To appear in Theoretical Population Biology)