Spatial scale and divergent patterns of variation in adapted traits in the ocean

Abstract

Ecology Letters (2012) Abstract The geography of adaptive genetic variation is crucial to species conservation yet poorly understood in marine systems. We analyse the spatial scale of genetic variation in traits that broadly display adaptation throughout the range of a highly dispersive marine species. We conducted common garden experiments on the Atlantic silverside, Menidia menidia, from 39 locations along its 3 000 km range thereby mapping genetic variation for growth rate, vertebral number and sex determination. Each trait displayed unique clinal patterns, with significant differences (adaptive or not) occurring over very small distances. Breakpoints in the cline differed among traits, corresponding only partially with presumed eco‐geographical boundaries. Because clinal patterns are unique to each selected character, neutral genes or those coding for a single character cannot serve as proxies for the genetic structure as a whole. Conservation plans designed to protect essential genetic subunits of a species will need to account for such complex spatial structures.

Transcriptomics and Fitness Data Reveal Adaptive Plasticity of Thermal Tolerance in Oysters Inhabiting Different Tidal Zones

“…Physiological responses of organisms to environmental changes are particularly important given the current scenario of global warming. In addition to the fitness-related trait of growth (Hice et al, 2012; Burford et al, 2014), the responses to acute thermal stress under sublethal and extreme temperatures have been frequently used to evaluate temperature adaptation at whole-organism, cellular, and biochemical levels (Somero, 2012; Yampolsky et al, 2014). Furthermore, in recent studies, molecular phenotypes (such as gene expression) are being increasingly used to identify adaptive divergence in response to a wide range of abiotic stressors, especially temperature (Somero, 2012; Bedulina et al, 2013; Kenkel et al, 2013; Dayan et al, 2015).…”

Long‐term acclimation to reciprocal light conditions suggests depth‐related selection in the marine foundation speciesPosidonia oceanica

“…Patterns of genetic and phenotypic variation of plant and animal populations are closely related to the magnitude of environmental heterogeneity in which they live (Conover, Duffy, & Hice, 2009; Endler, 1977; Hice, Duffy, Munch, & Conover, 2012) and are often independent from geographic distances (Richardson, Urban, Bolnick, & Skelly, 2014). Differential response of distinct populations to local environmental features either can fall within the phenotypic plasticity range of the species (Hall et al., 2007; Pfennig et al., 2010; Schlichting, 1986; Thibert‐Plante & Hendry, 2011) or can be due to evolutionary changes with underlying genetic differentiation among populations (Dowdall et al., 2012; Sanford & Kelly, 2011; Savolainen, Lascoux, & Merilä, 2013).…”

Metapopulation patterns of additive and nonadditive genetic variance in the sea bass (Dicentrarchus labrax)

“…The integration of phenogeography and phylogeography should contribute to better understanding of functional phenotypic evolution, and then fitness performance within and among lineages (Zamudio, Bell, & Mason, 2016). However, phenogeography—with the noticeable exception of counter‐ and cogradient variation studies (Conover, Duffy, & Hice, 2009; Hice, Duffy, Munch, & Conover, 2012) and few Q ST ‐F ST studies (DeFaveri & Merilä, 2013)—remains largely neglected in marine species. Indeed, while studies regarding changes in quantitative phenotypic differences mediated by trait plasticity and/or genetic processes are obviously present in the literature associated to evolutionary ecology of marine species (Conover et al., 2006; Sanford & Kelly, 2011), most studies concentrated at the molecular level (i.e., gene expression studies, population genetics/genomics) rather than on quantitative biological traits aiming to document the causes of variation of an organism phenotype over a large geographic scale, and their impact on fitness.…”