Developmental plasticity in thermal tolerance: Ontogenetic variation, persistence, and future directions

• Published in: Ecology letters 2022-10, Vol.25 (10), p.2245-2268
• Main Authors: Pottier, Patrice, Burke, Samantha, Zhang, Rose Y., Noble, Daniel W. A., Schwanz, Lisa E., Drobniak, Szymon M., Nakagawa, Shinichi
• Format: Article
• Language: English
• Subjects: acclimation; Acclimatization - physiology; Changing environments; Climate Change; Climate prediction; climate vulnerability; critical thermal limits; CTmax; Developmental plasticity; Developmental stages; Ecological effects; Embryos; Environmental changes; Environmental impact; heat tolerance; Hot Temperature; Impact prediction; ontogenetic variation; Ontogeny; persistence; phenotypic plasticity; Plastic properties; Plasticity; Plastics; reversibility; Synthesis; systematic review; Temperature; Temperature tolerance; Thermal environments; Thermal stress
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/ele.14083

Understanding the factors affecting thermal tolerance is crucial for predicting the impact climate change will have on ectotherms. However, the role developmental plasticity plays in allowing populations to cope with thermal extremes is poorly understood. Here, we meta‐analyse how thermal tolerance is initially and persistently impacted by early (embryonic and juvenile) thermal environments by using data from 150 experimental studies on 138 ectothermic species. Thermal tolerance only increased by 0.13°C per 1°C change in developmental temperature and substantial variation in plasticity (~36%) was the result of shared evolutionary history and species ecology. Aquatic ectotherms were more than three times as plastic as terrestrial ectotherms. Notably, embryos expressed weaker but more heterogenous plasticity than older life stages, with numerous responses appearing as non‐adaptive. While developmental temperatures did not have persistent effects on thermal tolerance overall, persistent effects were vastly under‐studied, and their direction and magnitude varied with ontogeny. Embryonic stages may represent a critical window of vulnerability to changing environments and we urge researchers to consider early life stages when assessing the climate vulnerability of ectotherms. Overall, our synthesis suggests that developmental changes in thermal tolerance rarely reach levels of perfect compensation and may provide limited benefit in changing environments. Understanding the role developmental plasticity plays in allowing populations to cope with thermal extremes is critical. Here, we meta‐analysed how thermal tolerance is impacted by early thermal environments using data from 138 ectothermic species. We found that developmental changes in thermal tolerance are not sufficient to buffer ectotherms from rising temperatures and that embryonic stages may represent a critical window of vulnerability to changing environments.