Epigenetics in natural animal populations

Abstract

Phenotypic plasticity is an important mechanism for populations to buffer themselves from environmental change. While it has long been appreciated that natural populations possess genetic variation in the extent of plasticity, a surge of recent evidence suggests that epigenetic variation could also play an important role in shaping phenotypic responses. Compared with genetic variation, epigenetic variation is more likely to have higher spontaneous rates of mutation and a more sensitive reaction to environmental inputs. In our review, we first provide an overview of recent studies on epigenetically encoded thermal plasticity in animals to illustrate environmentally-mediated epigenetic effects within and across generations. Second, we discuss the role of epigenetic effects during adaptation by exploring population epigenetics in natural animal populations. Finally, we evaluate the evolutionary potential of epigenetic variation depending on its autonomy from genetic variation and its transgenerational stability. Although many of the causal links between epigenetic variation and phenotypic plasticity remain elusive, new data has explored the role of epigenetic variation in facilitating evolution in natural populations. This recent progress in ecological epigenetics will be helpful for generating predictive models of the capacity of organisms to adapt to changing climates.

A mother’s legacy: the strength of maternal effects in animal populations

“…Moreover, important proximate maternal effects are stronger in plants than animals (e.g. transgenerational chromatin marking; Hu & Barrett ). Our estimates for the cumulative influence of maternal effects should therefore be viewed as conservative for the broader diversity of eukaryotes as well.…”

Genome‐scale sampling suggests cryptic epigenetic structuring and insular divergence in Canada lynx

“…DNA methylation has been implicated in mediating ecologically relevant traits in response to varied environmental conditions (Artemov et al, ; Baerwald et al, ; Lea, Altmann, Alberts, & Tung, ), primarily due to its regulatory relationship with gene expression, particularly around CpG islands that are dense clusters of cytosine‐guanine dinucleotides (Fujita et al, ; Lorincz, Dickerson, Schmitt, & Groudine, ; Maunakea et al, ). If heritable epigenetic modifications are imparted by specific environments, and these modifications increase fitness regardless of underlying genetic sequence (Herman & Sultan, ), then these epigenetic loci have important long‐term evolutionary consequences (Hu & Barrett, ). However, the relationship between epigenetic modifications and underlying genetic sequence is difficult to disentangle, where epigenetic modifications fall on a spectrum of complete dependency on a genetic variant, semi‐dependency where genetic variation does not explain the entirety of the phenotypic variation, or autonomy where epigenetic modifications exist independently of genetic variation (Richards, ).…”

Dynamic changes in DNA methylation during embryonic and postnatal development of an altricial wild bird

“…There is increasing interest among ecologists and evolutionary biologists in the potential for epigenetic mechanisms to shape environmentally induced phenotypic responses (Angers, Castonguay, & Massicotte, 2010;Bossdorf, Richards, & Pigliucci, 2008;Hu & Barrett, 2017;Verhoeven, VonHoldt, & Sork, 2016). Accumulating evidence demonstrates that epigenetic marks can be induced or removed in response to environmental cues in natural populations of plants and animals (Gugger, Fitz-Gibbon, Pellegrini, & Sork, 2016;Herrera & Bazaga, 2011;Lea, Altmann, Alberts, & Tung, 2016).…”