Maladaptive plasticity facilitates evolution of thermal tolerance during an experimental range shift

Aoife M. Leonard*, Lesley T. Lancaster

*Corresponding author for this work

Research output: Contribution to journalArticle

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Abstract

Background
Many organisms are responding to climate change with dramatic range shifts, involving plastic and genetic changes to cope with novel climate regimes found at higher latitudes. Using experimental lineages of the seed beetle Callosobruchus maculatus, we simulated the initial phase of colonisation to progressively cooler and/or more variable conditions, to investigate how adaptation and phenotypic plasticity contribute to shifts in thermal tolerance during colonisation of novel climates.

Results
We show that heat and cold tolerance rapidly evolve during the initial stages of adaptation to progressively cooler and more variable climates. The evolved shift in cold tolerance is, however, associated with maladaptive plasticity under the novel conditions, resulting in a pattern of countergradient variation between the ancestral and novel, fluctuating thermal environment. In contrast, lineages exposed to progressively cooler, but constant, temperatures over several generations expressed only beneficial plasticity in cold tolerances and no evolved response.

Conclusions
We propose that thermal adaptation during a range expansion to novel, more variable climates found at high latitudes and elevations may typically involve genetic compensation arising from maladaptive plasticity in the initial stages of adaptation, and that this form of (countergradient) thermal adaptation may represent an opportunity for more rapid and labile evolutionary change in thermal tolerances than via classic genetic assimilation models for thermal tolerance evolution (i.e., selection on existing reaction norms). Moreover, countergradient variation in thermal tolerances may typically mask cryptic genetic variability for these traits, resulting in apparent evolutionary stasis in thermal traits.
Original languageEnglish
Article number47
Number of pages11
JournalBMC Evolutionary Biology
Volume20
DOIs
Publication statusPublished - 23 Apr 2020

Keywords

  • Countergradient variation
  • Maladaptive plasticity
  • Thermal fluctuations
  • Range-shifts
  • Genetic compensation
  • Callosobruchus maculatus
  • PHENOTYPIC PLASTICITY
  • CLIMATE-CHANGE
  • VARIABILITY
  • HEAT
  • RESPONSES
  • TEMPERATURE
  • ADAPTATION
  • COUNTERGRADIENT VARIATION
  • GENE-EXPRESSION
  • STRESS

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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