Beyond rate of living

Area of Science:

• Gerontology
• Evolutionary Biology
• Mammalian Physiology

Background:

• The rate of living theory of aging, linking metabolic rate to lifespan, has faced challenges due to inconsistencies across mammalian species.
• Aging is fundamentally linked to cellular metabolic processes, specifically entropy production and counterentropic repair mechanisms.

Purpose of the Study:

• To investigate the relationship between cellular metabolism, counterentropic mechanisms, and mammalian lifespan.
• To propose and validate a new predictor of mammalian lifespan based on developmental rates relative to metabolic rate.

Main Methods:

• Analysis of data from 22 mammalian species across major orders, including metabolic rates, developmental periods, and lifespans.
• Comparison of species-specific "rate of becoming" (developmental rate relative to basal metabolic rate) with observed lifespans.

Main Results:

• The "rate of becoming" emerged as a significant predictor of mammalian lifespan, aligning with data from diverse species.
• Findings support the hypothesis that evolved counterentropic mechanisms, influenced by developmental rates, modulate aging and lifespan.
• The study reconciles aging with metabolism, moving beyond the limitations of the traditional rate of living concept.

Conclusions:

• Mammalian lifespan is influenced by the interplay between cellular entropy production and evolved counterentropic repair mechanisms.
• Species-specific developmental rates, relative to basal metabolic rate, are key determinants of aging and lifespan.
• Natural selection acting on traits influencing developmental rates may explain variations in counterentropic capacities and lifespan across mammalian orders.