Exploring links between climatic predictability and the evolution of within‐ and transgenerational plasticity

Abstract

In variable environments, phenotypic plasticity can increase fitness by providing tight environment‐phenotype matching. However, adaptive plasticity is expected to evolve only when the future selective environment can be predicted based on the prevailing conditions. That is, the juvenile environment should be predictive of the adult environment (within‐generation plasticity) or the parental environment should be predictive of the offspring environment (transgenerational plasticity). Moreover, the environmental predictability can also shape transient responses such as stress response in an adaptive direction. Here, we test links between environmental predictability and the evolution of adaptive plasticity by combining time series analyses and a common garden experiment using temperature as a stressor in a temperate butterfly ( Melitaea cinxia ). Time series analyses revealed that across season fluctuations in temperature over 48 years are overall predictable. However, within the growing season, temperature fluctuations showed high heterogeneity across years with low autocorrelations and the timing of temperature peaks were asynchronous. Most life‐history traits showed strong within‐generation plasticity for temperature and traits such as body size and growth rate broke the temperature‐size rule. Evidence for transgenerational plasticity, however, was weak and detected for only two traits each in an adaptive and non‐adaptive direction. We suggest that the low predictability of temperature fluctuations within the growing season likely disfavors the evolution of adaptive transgenerational plasticity but instead favors strong within‐generation plasticity.

Thermal plasticity in development and diapause strategy in a temperate butterfly across a latitudinal gradient

“…We acknowledge that in the field, photoperiod changes throughout the larval period and thus keeping photoperiod constant might affect our results. However, in M. cinxia, photoperiod was found to not significantly influence diapause onset in a preliminary experiment (Halali & Saastamoinen, 2022, see this article for further discussion on omitting photoperiod as a factor in our experiment). As a rule, splitting was done on the day that 50% of the larvae in the clutch moulted to the second instar, but in almost all families all larvae moulted to the second instar during the same day.…”

Clear effects of population and sex but not rearing temperature on stress tolerance in a temperate butterfly

“…Phenotypic plasticity is expected to be most beneficial in predictably variable environments (Chevin and Lande, 2015;Reed et al, 2010), since plastic organisms are at risk of a mismatch between environment and phenotype, leading to maladaptive plasticity, when environmental variation is not predictable (Ghalambor et al, 2007;Hoffmann and Bridle, 2022). Previous analysis from Finland, shows low predictability between spring and summer conditions (Halali and Saastamoinen, 2022).…”

DNA methylation dynamics in response to stress : An insight into stress-induced and stably inherited DNA methylation variants in asexual and sexual plants

“…By obtaining close to four new generations within a week, L. minor allows us to easily study the dynamics of DNA methylation across a large number of generations. Additionally, it is hypothesised that adaptive plasticity (and thus epigenetic variation) is expected to be more prominent in species that live in heterogeneous yet predictable environmental conditions (Halali & Saastamoinen, 2022;Leung et al, 2016Leung et al, , 2020Leung et al, , 2022Postuma et al, 2020). This is believed to be of particular importance in species with short generation time, whose offspring are more likely to experience the same environmental conditions as their parents (Burgess & Marshall, 2014;Leung et al, 2022;Postuma et al, 2020).…”