Premium
Repeatable inter‐individual variation in the thermal sensitivity of metabolic rate
Author(s) -
Réveillon Tom,
Rota Thibaut,
Chauvet Éric,
Lecerf Antoine,
Sentis Arnaud
Publication year - 2019
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1111/oik.06392
Subject(s) - repeatability , metabolic rate , trait , biology , adaptation (eye) , climate change , ecology , ectotherm , sensitivity (control systems) , variation (astronomy) , evolutionary biology , statistics , mathematics , physics , astrophysics , neuroscience , electronic engineering , computer science , engineering , programming language , endocrinology
Assessing whether trait variations among individuals are consistent over time and among environmental conditions is crucial to understand evolutionary responses to new selective pressures such as climate change. According to the universal thermal dependence hypothesis, thermal sensitivity of metabolic rate should not vary strongly and consistently among organisms, implying limited evolutionary response for metabolic traits under climate change. However, this hypothesis has been rarely tested at an individual level, leaving a gap in our understanding of climate change impacts on metabolic responses and their potential evolution. Using the amphipod Gammarus fossarum , we investigated the variability and repeatability of individual metabolic thermal reaction norms over time. We found large variations in both the thermal sensitivity (i.e. slope) and expression level (i.e. intercept) of individual metabolic reaction norms. Moreover, differences among individuals were consistent over time, and therefore repeatable. Inter‐individual variations in body mass resulted in a high repeatability of metabolic expression level but had no significant effect on the repeatability of thermal sensitivity. Overall, our results highlight that inter‐individual variability and repeatability of thermal reaction norms can be substantial. We conclude that these consistent differences among individuals should not be overlooked when apprehending the ecological and evolutionary effects of climate change.