A theoretical model of the evolution of actuarial senescence under environmental stress.

A theoretical model of the evolution of actuarial senescence under environmental stress. Exp Gerontol. 2015 Aug 31; Authors: Watson H, Cohen AA, Isaksson C Abstract Free-living organisms are exposed to a wide range of stressors, all of which can disrupt physiological regulatory mechanisms. The subsequent accumulation of somatic damage is widely believed to play a major role in the evolution of senescence. Organisms have evolved sophisticated physiological regulatory mechanisms to maintain homeostasis in response to environmental perturbations, but these systems are likely to be constrained in their ability to optimise robustness to multiple stressors due to functional correlations among these related traits. While evolutionary change can accelerate due to human ecological impacts, it remains to be understood how exposure to multiple environmental stressors could affect senescence rates and subsequently population dynamics and fitness. We used a theoretical evolutionary framework to quantify the potential consequences for the evolution of actuarial senescence in response to exposure to simultaneous physiological stressors - one versus multiple and additive versus synergistic - in a hypothetical population of avian "urban adapters". In a model in which multiple stressors have additive effects on physiology, species may retain greater capacity to recover, or respond adaptively, to environmental challenges. However, in the presence of hi...
Source: Experimental Gerontology - Category: Geriatrics Authors: Tags: Exp Gerontol Source Type: research