Programmed Aging Theory Information Maintenance and Repair Theories of Aging

Theorists agree that living organisms possess extensive maintenance and repair functions that act to repair damage. This is a major and obvious difference between living organisms and non-living entities and a main reason that the generic wear and tear theories do not work. As a result, there now exist both programmed and non-programmed theories of aging based on maintenance and repair functions.

Maintenance and Repair Functions

Here are examples of known maintenance and repair functions:

Non-Programmed Maintenance Theories of Aging

According to traditional evolutionary mechanics theory, an organism cannot evolve a mechanism whose primary purpose is to limit life span but can evolve maintenance mechanisms whose purpose is to extend life span. Because of Medawar's hypothesis, organisms do not need life spans longer than some multiple of their age of sexual maturity and therefore there is little or no evolutionary motivation towards developing and retaining maintenance mechanisms capable of delaying deterioration beyond that point.

Different manifestations of aging appear to be caused by greatly different mechanisms. Much heart disease is caused by buildup of artery deposits. Cancer appears to be caused by molecular changes that cause uncontrolled cell growth. These mechanisms are very different leading to the conclusion that different maintenance and repair mechanisms are involved in repair of damage leading to various different manifestations.  This leads to the idea that a number (potentially a large number) of different maintenance mechanisms evolved independently. If an animal species was troubled by excessively early heart disease it would evolve better anti-heart disease mechanisms. If cancer became a problem, it would evolve a better anti-cancer mechanism and so forth. Non-programmed maintenance theories suggest that in each species, the various maintenance mechanisms have each been tailored by the evolution process to that species' need for life span. In a short-lived species, all of the maintenance functions are somehow less effective and therefore unrepaired damage accumulates more rapidly than in a longer-lived species. 

PROS: Compatible with traditional evolutionary mechanics theory. CONS: Major problems explaining experimental observations.

Programmed Maintenance Theories of Aging

According to alternative evolutionary mechanics theories and associated aging theories, an organism can evolve both anti-aging functions necessary to achieve a life span loosely based on Medawar's criteria, and a life span regulation mechanism necessary to limit life span to a species-specific value also loosely based on Medawar's criteria. A life span exceeding the optimum life span for the species creates evolutionary disadvantage. Therefore, assuming the same sorts of maintenance functions described above, the combined system could be as described below. In this concept a biological life span regulation function purposely discontinues or slows maintenance functions at a species-unique age. Like most evolved biological functions, the proposed regulation mechanism is capable of adapting (within a genetically designed range) to local or temporary conditions via sense functions. In this concept the major difference between mammal species is in the control (clock, sense, signaling) mechanism as opposed to differences in each of the maintenance mechanisms.

A major feature of this concept is the existence of mechanisms that are common to multiple manifestations of aging including clock, sensory, and signaling functions. This contrasts with the non-programmed concept of independent maintenance functions and has major medical implications.

PROS: Excellent fit with experimental evidence. CONS: Incompatible with traditional evolutionary mechanics theory; requires an alternative mechanics theory.


Observational Evidence Favoring Programmed Maintenance Aging Theories

Azinet LLC 12/2009