Adaptive phenotypic plasticity and resilience of vertebrates to increasing climatic unpredictability

Abstract

As ecosystems undergo global changes, there is increasing interest in understanding how organisms respond to changing environments. Recent evidence drawn from available vertebrate studies suggests that most of the phenotypic responses to climate change would be due to plasticity. We hypothesize that organisms that have evolved in unpredictable environments inform us about the mechanisms of phenotypic plasticity which provide an adaptive response to climate instability. As climate changes increase climatic hazards, these resilience mechanisms are expected to spread within species, populations and communities. We review studies that have demonstrated the importance of phenotypic plasticity in different life-history traits in overcoming climate uncertainty. We focus on organisms from unstable, recurrently energetically restrictive environments which possess a variety of morphological, physiological and/or behavioural adaptations to climate-driven selective pressures. First, we treat plastic morphological changes in response to fluctuating food availability. Adjustment of morphometric traits and/or organ size to energy supply would be essential in harsh environments. Second, we review the role of flexible energy-saving mechanisms, such as daily torpor, hibernation and energy storage, in overcoming climate-driven energetic shortages. Lastly, we address the role of plastic modulation of reproduction in fine-tuning the energy allocation to offspring production according to environmental conditions, with an emphasis on opportunistic breeding. Overall, we predict that species (or genotypes) possessing these efficient physiological mechanisms of resilience to unpredictable water and food fluctuations will be selectively advantaged in the face of increasing climatic instability.

Hormonally mediated maternal effects, individual strategy and global change

“…Some authors consider phenotypic plasticity unlikely to enable organisms to adapt to altered environments, at least in the short term [3]. Other authors argue that the pace of environmental change exceeds the potential evolutionary response to selection, hence plasticity is likely to be a major avenue for viability of species in novel environments [9,151].…”

“…Predicting the responses of organisms to climate change is complicated by two characteristics of the expected changes to global ecosystems. Sustained warming should impose directional selection favouring adaptation to higher temperatures [9]. However, climate change also is expected to yield circumstances involving unpredictable and episodic extreme climatic events.…”

“…It is likely that species characterized by phenotypic flexibility (i.e. plasticity) should be more resilient to climate change [9,11]. Key questions are how can environmental cues modulate changes in the phenotype [16] and what constraints may limit the potential for plasticity to facilitate coping with changing environments [10,17].…”

“…Third, individuals within a population may persist in rapidly changing environments by behavioural or physiological compensation, i.e. phenotypic plasticity [5,[9][10][11]. Phenotypic plasticity may entail different phenomena including within-individual plasticity (i.e.…”

Effects of maternal and offspring environmental conditions on growth, development and diapause in latitudinal yellow dung fly populations

“…Blanckenhorn & Fairbairn 1995, Blanckenhorn & Demont 2004, Fischer & Karl 2010. The most common cue indicating seasonal change is the photoperiod, which is generally a more reliable predictor of seasonal change than are alternative cues such as temperature or humidity, at least at higher latitudes (Tauber et al 1986, Danks 1987, Hanski 1988, Bradshaw & Holzapfel 2007, Canale & Henry 2010. Temperature and photoperiod are often correlated, however, so both variables may be used as cues across latitudes and can occasionally conflict with each other, leading to local differences in phenotypic plasticity (Mousseau & Dingle 1991, De Block & Stoks 2003, Tachibana & Humata 2004.…”