The role of transgenerational epigenetic inheritance in diversification and speciation

Abstract

Epigenetic effects -Broadly defined, any phenotypic variations that arise through processes other than those involving alterations in the base-pair nucleotide sequence of DNA.Inheritance -The process by which phenotypic characters (including behaviors) are transmitted from parent to offspring.Isolating mechanism -Any behavioral, morphological, physiological, genetic, or biochemical features of organisms that prevent gene exchange between populations (sensu Dobzhansky [1]). Phenotypic diversification -As used here, the evolution of different traits in different populations. Phenotypic plasticity -The capacity of a single genotype to produce different phenotypes in direct response to varying environmental conditions.Speciation -The process by which barriers to gene flow evolve between populations within an ancestral species, resulting in two or more descendent species. Species -Groups of interbreeding natural populations that are reproductively isolated from other such groups (sensu Mayr [2,3]). Transgenerational epigenetic inheritance -The inheritance of phenotypic characters through processes other than those involving changes in DNA sequence, such as chromatin marking, maternal effects, parasite transmission, and learning (sensu Jablonka and Lamb [4]). Section 1Transgenerational epigenetic inheritance: a challenge for evolutionary biology The importance of inheritance for evolutionA central goal of biology is to explain the diversity of life. Namely, why are there so many different kinds of living things, and why do they tend to differ from each other phenotypically? One hundred and fifty years ago, Darwin provided an answer, which he summarized in the last paragraph of On the Origin of Species [5]:"It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, AbstractInheritance is crucial to the evolutionary process. Although most evolutionary biologists assume that inheritance occurs exclusively through changes in DNA base sequence, it has long been known that inheritance can also occur through epigenetic mechanisms, such as chromatin marking, maternal effects, parasite transmission, or learning. In recent years, the possibility that such transgenerational epigenetic inheritance mechanisms can mediate long-term evolutionary change has received increased attention. Here, we consider the potential contribution of transgenerational epigenetic inheritance in driving diversification and speciation. As we describe, a growing body of theoretical and empirical studies suggests that epigenetic inheritance can accelerate the likelihood that genetic change will occur and thereby facilitate speciation. Additionally, evolution and diversification can p...

Epigenetic divergence as a potential first step in darter speciation

“…Only recently has divergence in DNA methylation been proposed as a possible aid in speciation (Flatscher et al . ; Pfenning & Servedio ; Smith & Ritchie ), and several cases in the literature support this hypothesis (Shaposhnikov ; Field et al . ; Anway et al .…”

“…Epigenetic contributions to speciation, and reproductive isolation specifically, are poorly understood, but have seen increased interest in recent years (reviewed in Smith & Ritchie ; Pfenning & Servedio ; Lafon‐Placette & Köhler ; Skinner ). Perhaps the best‐studied epigenetic contributors to reproductive isolation in animals are learning (reviewed in Verzijden et al .…”

Within-generation and transgenerational plasticity of mate choice in oceanic stickleback under climate change

“…body size, ornamentation, condition) and mating preferences for these traits can be altered by G Â E and parental effects [18]. However, empirical studies explicitly demonstrating the interaction between parental environment, offspring environment and offspring mate choice are scarce (but see examples of sexual imprinting [19,20]).…”

Evolutionary ecology of microorganisms: from the tamed to the wild

“…Justification for this 410 approach is as follows: in general, rDNA is a stable molecule that is widely used to infer the presence (and potential activity) of a population. In contrast, rRNA is an ephemeral molecule 412 that is only produced by growing cells, which require ribosomes for protein synthesis (95 Last, epigenetic processes can also affect the temporal scale of eco-evolutionary 420 processes by allowing organisms to rapidly respond to environmental signals and pass this response on to its offspring (99). Epigenetic processes refer to non-genetic mechanisms (i.e., not 422 directly related to differences in nucleotide sequence) that cause variability in gene expression that can result in phenotypic variation subject to natural selection.…”