Is there plasticity in developmental instability? The effect of daily thermal fluctuations in an ectotherm. Issue 24 (2nd November 2017)

• Record Type: Journal Article
• Authors: Kielland, Øystein Nordeide; Bech, Claus; Einum, Sigurd
• Is Part Of: Ecology and evolution. Volume 7:Issue 24(2017:Dec.)
• Page Start: 10567
• Page End: 10574
• Publication Date: 2017-11-02
• Subjects: allometry -- bioenergetics -- climate change -- development -- heritability -- ontogeny -- quantitative genetics; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.3556
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Diversified bet‐hedging (DBH) by production of within‐genotype phenotypic variance may evolve to maximize fitness in stochastic environments. Bet‐hedging is generally associated with parental effects, but phenotypic variation may also develop throughout life via developmental instability (DI). This opens for the possibility of a within‐generation mechanism creating DBH during the lifetime of individuals. If so, DI could in fact be a plastic trait itself; if a fluctuating environment indicates uncertainty about future conditions, sensing such fluctuations could trigger DI as a DBH response. However, this possibility has received little empirical attention. Here, we test whether fluctuating environments may elicit such a response in the clonally reproducing crustacean Daphnia magna . Specifically, we exposed genetically identical individuals to two environments of different thermal stability (stable vs. pronounced daily realistic temperature fluctuations) and tested for effects on DI in body mass and metabolic rate shortly before maturation. Furthermore, we also estimated the genetic variation in DI. Interestingly, fluctuating temperatures did not affect body mass, but metabolic rate decreased. We found no evidence for plasticity in DI in response to environmental fluctuations. The lack of plasticity was common to all genotypes, and for both traits studied. However, we found considerable evolvability for DI, which implies a general evolutionary potential for DBH under selection for increased phenotypic variance. Abstract : This study investigates whether developmental instability (DI) could increase as a response to a fluctuating environment during ontogeny. If this is true, developmental instability could potentially exist as an evolutionary adaptation to unpredictable environments. We do not find such a response to fluctuating environments, which suggests that DI is not responding within generations to environmental variance per se.