Key questions in the genetics and genomics of eco-evolutionary dynamics

Abstract

Increasing acceptance that evolution can be 'rapid' (or 'contemporary') has generated growing interest in the consequences for ecology. The genetics and genomics of these 'eco-evolutionary dynamics' will be-to a large extent-the genetics and genomics of organismal phenotypes. In the hope of stimulating research in this area, I review empirical data from natural populations and draw the following conclusions. (1) Considerable additive genetic variance is present for most traits in most populations. (2) Trait correlations do not consistently oppose selection. (3) Adaptive differences between populations often involve dominance and epistasis. (4) Most adaptation is the result of genes of small-to-modest effect, although (5) some genes certainly have larger effects than the others. (6) Adaptation by independent lineages to similar environments is mostly driven by different alleles/genes. (7) Adaptation to new environments is mostly driven by standing genetic variation, although new mutations can be important in some instances. (8) Adaptation is driven by both structural and regulatory genetic variation, with recent studies emphasizing the latter. (9) The ecological effects of organisms, considered as extended phenotypes, are often heritable. Overall, the study of eco-evolutionary dynamics will benefit from perspectives and approaches that emphasize standing genetic variation in many genes of small-to-modest effect acting across multiple traits and that analyze overall adaptation or 'fitness'. In addition, increasing attention should be paid to dominance, epistasis and regulatory variation.

The other 96%: Can neglected sources of fitness variation offer new insights into adaptation to global change?

“…While the evolutionary roles of nonadditive genetic and maternal environmental effects remain controversial, theory and data argue that they can substantially alter evolutionary trajectories, as well as magnitudes and effects of gene flow (Dey, Proulx, & Teotónio, 2016; Hendry, 2013; Kirkpatrick & Lande, 1989; Rasanen & Kruuk, 2007; Wade, 2002; Wang et al., 1998). Little is known, however, of their relative contributions to fitness variation in natural populations, and even less of their multivariate, multi‐environment impacts that might exacerbate or ameliorate global‐change stressors.…”

“…These scenarios, of course, assume that nonadditive genetic effects are to an extent stable across generations. However, growing evidence of their effects on population differentiation following environmental change (Carroll, 2007; Hendry, 2013) suggests some capacity for this to occur, particularly when populations undergo decline or subdivision (Roff & Emerson, 2006; Wade, 2002). If such is the case for Galeolaria , then cross‐environment covariation in nonadditive genetic effects on fitness could potentially influence the evolutionary dynamics of our study population under global change.…”

Genomic tools for new insights to variation, adaptation, and evolution in the salmonid fishes: a perspective for charr

“…As genomic data can be collected more readily, the greatest gains in mining the genomics of adaptive traits will come from environment and phenotype matching, as well as increasing levels of biological replication (populations and individuals) (Elmer & Meyer, 2011;Hendry, 2013;Roesti et al, 2014). Future research will also benefit from direct and indirect functional validation, for example, the comparisons possible with the growing available genomic resources for salmonids (Pavey et al, 2012;Primmer et al, 2013).…”

Adaptation in marine invasion: a genetic perspective

“…Such case studies in rapid adaptation are likely based largely on standing genetic variation rather than new mutations, as was the case with repeated marine to freshwater transitions in the extensively-studied stickleback system (Colosimo et al 2005;Jones et al 2012). Standing variation is believed to be particularly important when genetic diversity is relatively high and selective pressures are not novel (reviewed in Hendry 2013). While bottlenecking may reduce diversity in invasive populations, multiple introductions-as demonstrated in several prominent invasions-can increase diversity and produce populations with standing genetic variation that reflects a broader range of past selective environments than was present in any single native population (reviewed in Roman and Darling 2007).…”