Rapid adaptive evolution of the diapause program during range expansion of an invasive mosquito

Abstract

In temperate climates, the recurring seasonal exigencies of winter represent a fundamental physiological challenge for a wide range of organisms. In response, many temperate insects enter diapause, an alternative developmental program, including developmental arrest, that allows organisms to synchronize their life cycle with seasonal environmental variation. Geographic variation in diapause phenology contributing to local climatic adaptation is well documented. However, few studies have examined how the rapid evolution of a suite of traits expressed across the diapause program may contribute to climatic adaptation on a contemporary timescale. Here, we investigate the evolution of the diapause program over the past 35 years by leveraging a “natural experiment” presented by the recent invasion of the Asian tiger mosquito, Aedes albopictus, across the eastern United States. We sampled populations from two distinct climatic regions separated by 6° of latitude (∼700 km). Using common‐garden experiments, we identified regional genetic divergence in diapause‐associated cold tolerance, diapause duration, and postdiapause starvation tolerance. We also found regional divergence in nondiapause thermal performance. In contrast, we observed minimal regional divergence in nondiapause larval growth traits and at neutral molecular marker loci. Our results demonstrate rapid evolution of the diapause program and imply strong selection caused by differences in winter conditions.

Local environment‐driven adaptive evolution in a marine invasive ascidian (Molgula manhattensis)

“…Additionally, both the rate and range of environmental changes during biological invasions are often orders of magnitude faster and greater than what species experience in natural processes (e.g., seasonal fluctuations) in their native habitats (Lin et al, 2017). In order to cope with various environmental challenges, some invasive species have considerable potentials for rapid adaptation (Batz et al, 2020;Lee, 2002). Such a common feature indicates that invasive species can provide promising materials to investigate how organisms adapt to changing environments (Bock et al, 2015;Zhan et al, 2015).…”

Maternally Instigated Diapause in Aedes albopictus: Coordinating Experience and Internal State for Survival in Variable Environments

“…Although our understanding of the mechanisms of diapause termination are incomplete, Ae. albopictus embryos terminate maternally instigated diapause after a period of time to enter the “quiescence” phase, in which they become responsive to cues that signal the return of favorable conditions and development resumes ( Batz et al, 2020 ). If unfavorable conditions persist, development may remain suppressed in post-diapause quiescence but this form of dormancy is distinguishable from diapause because it can be terminated immediately upon exposure to favorable conditions ( Tauber and Tauber, 1976 ).…”

Indications for rapid evolution of trait means and thermal plasticity in range‐expanding populations of a butterfly

“…While there is accumulating evidence for adjustments in thermal tolerance during range expansions (e.g. Batz et al, 2020; Titelboim et al, 2019), little is known about the relative contribution of increased baseline tolerance versus plasticity, and the few existing studies yielded mixed results (Lancaster et al, 2015; Leonard & Lancaster, 2020; Nguyen et al, 2019). Moreover, even fewer studies considered developmental plasticity (long‐term acclimation to thermal conditions during the developmental period) as potential driver of ectotherm thermotolerance (Bowler & Terblanche, 2008; Diamond et al, 2017) and for increasing fitness‐related traits in range‐expanding species (Carbonell & Stoks, 2020).…”