Climate change and ageing in ectotherms

Abstract

Human activity is changing climatic conditions at an unprecedented rate. The impact of these changes may be especially acute on ectotherms since they have limited capacities to use metabolic heat to maintain their body temperature. An increase in temperature is likely to increase the growth rate of ectothermic animals, and may also induce thermal stress via increased exposure to heat waves. Fast growth and thermal stress are metabolically demanding, and both factors can increase oxidative damage to essential biomolecules, accelerating the rate of ageing. Here, we explore the potential impact of global warming on ectotherm ageing through its effects on reactive oxygen species production, oxidative damage, and telomere shortening, at the individual and intergenerational levels. Most evidence derives primarily from vertebrates, although the concepts are broadly applicable to invertebrates. We also discuss candidate mechanisms that could buffer ectotherms from the potentially negative consequences of climate change on ageing. Finally, we suggest some potential applications of the study of ageing mechanisms for the implementation of conservation actions. We find a clear need for more ecological, biogeographical, and evolutionary studies on the impact of global climate change on patterns of ageing rates in wild populations of ectotherms facing warming conditions. Understanding the impact of warming on animal life histories, and on ageing in particular, needs to be incorporated into the design of measures to preserve biodiversity to improve their effectiveness.

“Heat waves” experienced during larval life have species-specific consequences on life-history traits and sexual development in anuran amphibians

“…Heat can result in delayed metamorphosis (Goldstein et al 2017), reduced body mass (Harkey and Semlitsch 1988, Phuge 2017, Lambert et al 2018, disabled locomotor activity (Goldstein et al 2017), sex reversal (Dournon et al 1984, Wallace and Wallace 2000, Mikó et al 2021) and biased sex ratios (Phuge 2017, Lambert et al 2018, Ruiz-Garciá et al 2021. Exposure of adult frogs to 30 °C or higher can increase stress hormone levels (Juráni et al 1973, Narayan andHero 2014) and enhance the processes that contribute to accelerated ageing (Burraco et al 2020).…”

Does fluctuating asymmetry of wing traits capture relative environmental stress in a lepidopteran?

“…Temperature and diet manipulations were selected as stressors, as it is widely agreed that these are very influential determinants of individual survival and reproduction as well as distribution of many heterotrophic species (Boersma et al., 2016; Clissold & Simpson, 2015; Cross et al., 2015; Kim et al., 2020; Sørensen et al., 2016). A high temperature stressor was selected because of its relevance to global climate change, to which ectotherms may be particularly vulnerable (Burraco et al ., 2020; Deutsch et al., 2008; Huey & Berrigan, 2001; Huey & Kingsolver, 1989). Evidence suggests that ectotherms tend to lack capacity to physiologically adjust maximum temperature tolerance (Gunderson & Stillman, 2015), and thermal performance curves of insects and other ectotherms decelerate rapidly above an optimal plateau (Clissold & Simpson, 2015; Deutsch et al., 2008; Sutton et al., 2018).…”

Within- and Trans-Generational Environmental Adaptation to Climate Change: Perspectives and New Challenges

“…Indeed, scenario-based projections of climate change suggest that spawning adults have significantly narrower thermal tolerances (Dahlke et al, 2020). In addition, environmental variation can induce alteration in neuroendocrine pathways, modifying metabolism, disrupting homeostasis and exacerbating production of reactive oxygen species, leading to acceleration of development and aging (Burraco et al, 2020). Therefore, different developmental stages are likely to respond to stressors through distinct mechanisms and with different sensitivity and plasticity.…”