Strong phenotypic plasticity limits potential for evolutionary responses to climate change

Abstract

Phenotypic plasticity, the expression of multiple phenotypes from one genome, is a widespread adaptation to short-term environmental fluctuations, but whether it facilitates evolutionary adaptation to climate change remains contentious. Here, we investigate seasonal plasticity and adaptive potential in an Afrotropical butterfly expressing distinct phenotypes in dry and wet seasons. We assess the transcriptional architecture of plasticity in a full-factorial analysis of heritable and environmental effects across 72 individuals, and reveal pervasive gene expression differences between the seasonal phenotypes. Strikingly, intra-population genetic variation for plasticity is largely absent, consistent with specialisation to a particular environmental cue reliably predicting seasonal transitions. Under climate change, deteriorating accuracy of predictive cues will likely aggravate maladaptive phenotype-environment mismatches and increase selective pressures on reaction norms. However, the observed paucity of genetic variation for plasticity limits evolutionary responses, potentially weakening prospects for population persistence. Thus, seasonally plastic species may be especially vulnerable to climate change.

Phenotypic plasticity, but not adaptive tracking, underlies seasonal variation in post‐cold hardening freeze tolerance of Drosophila melanogaster

“…Instead, post‐cold hardening freeze tolerance is highly dependent on a variety of environmental and life history conditions. Understanding the use of plasticity versus adaptive tracking is critical for modeling and predicting how organisms will cope with a changing climate and the associated shifts in environment and habitat range (Hoffmann & Sgrò, ; Merila & Hendry, ; Oostra, Saastamoinen, Zwaan, & Wheat, ; Stoks, Geerts, & Meester, ). Based on our data, we concur with Ayrinhac et al () that the factors that influence plasticity may be more important than standing genetic variation for some organisms facing thermal extremes.…”

Phenology as a process rather than an event: from individual reaction norms to community metrics

“…, but see Oostra et al. ), data on this are sparse across all types of organisms, even for the relatively well‐studied topic of plant flowering time (Ehrlén ). Unfortunately, the relationship between within‐season phenotypic selection on phenology (which is relatively easy to measure) and selection on reaction norms (much harder to measure) is not straightforward.…”

Individual variation in plasticity dulls transgenerational responses to stress

“…This observation is important because it suggests a link between the average strength of plasticity in populations and patterns of individual variance in plasticity (Oostra, Saastamoinen, Zwaan, & Wheat, ; Porlier et al, ). In particular, clonal variation in the direction of transgenerational plasticity could foreshadow strong selection operating on reaction norms and increased potential for the evolution of plasticity (Ghalambor et al, ; Schlichting & Pigliucci, ).…”