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

Watson, Hannah LU ; Cohen, A A and Isaksson, Caroline LU (2015) In Experimental Gerontology 71(Online 31 August 2015). p.80-88
Abstract
Free-living organisms are exposed to a wide range of stressors, all of which can disrupt components of stress-related and detoxification physiology. 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 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... (More)
Free-living organisms are exposed to a wide range of stressors, all of which can disrupt components of stress-related and detoxification physiology. 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 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 high synergy, physiological dysregulation suddenly occurs, leading to a rapid increase in age-dependent mortality and subsequent population collapse. Our results suggest that, if the synergistic model is correct, population crashes in environmentally-stressed species could happen quickly and with little warning, as physiological thresholds of stress resistance are overcome. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Experimental Gerontology
volume
71
issue
Online 31 August 2015
pages
80 - 88
publisher
Elsevier
external identifiers
  • pmid:26335620
  • wos:000364988800010
  • scopus:84946606643
ISSN
1873-6815
DOI
10.1016/j.exger.2015.08.009
language
English
LU publication?
yes
id
91a27df6-eef6-495c-b09e-fcfc257df684 (old id 8043265)
date added to LUP
2015-10-28 14:38:17
date last changed
2017-01-01 03:50:48
@article{91a27df6-eef6-495c-b09e-fcfc257df684,
  abstract     = {Free-living organisms are exposed to a wide range of stressors, all of which can disrupt components of stress-related and detoxification physiology. 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 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 high synergy, physiological dysregulation suddenly occurs, leading to a rapid increase in age-dependent mortality and subsequent population collapse. Our results suggest that, if the synergistic model is correct, population crashes in environmentally-stressed species could happen quickly and with little warning, as physiological thresholds of stress resistance are overcome.},
  author       = {Watson, Hannah and Cohen, A A and Isaksson, Caroline},
  issn         = {1873-6815},
  language     = {eng},
  number       = {Online 31 August 2015},
  pages        = {80--88},
  publisher    = {Elsevier},
  series       = {Experimental Gerontology},
  title        = {A theoretical model of the evolution of actuarial senescence under environmental stress.},
  url          = {http://dx.doi.org/10.1016/j.exger.2015.08.009},
  volume       = {71},
  year         = {2015},
}