Reliability Theory of Aging

What it proposes

The Gavrilovs apply reliability engineering to biological aging:

• An organism is a complex system with redundant components (multiple kidneys’ nephrons, neurons, mitochondria per cell, etc.).
• Components have a per-time-unit failure probability.
• Random failure accumulates; system function persists while sufficient redundancy remains.
• System failure (death) becomes likely when redundancy is exhausted.

Predictions

• Mortality should rise exponentially with age (consistent with Gompertz law).
• Mortality should plateau at extreme age once redundancy is exhausted in survivors (the late-life mortality plateau seen in flies, mice, and controversially humans).
• Reducing initial component failure rate, or starting with more redundancy, should extend lifespan.

Strengths

• Unifies Gompertz mortality with biological reality.
• Predicts late-life plateau without requiring specific mechanisms.
• Frames aging as accumulation of micro-failures rather than a single cause.

Limitations

• Says little about what the components are or how to slow their failure.
• Doesn’t explain why caloric restriction extends lifespan (which reliability theory in its purest form would not predict).
• Engineering-redundancy framing under-emphasises the active maintenance and adaptation that biology can perform.

Related entries

Gompertz law, Free radical theory, Negligible senescence (concept).