Non-genetic inheritance in evolutionary theory - the importance of plant studies

Abstract

AbstractEmerging evidence points to a causal role for epigenetic variation in evolution, but evolutionary biologists have been reluctant to incorporate epigenetics into modern evolutionary theory. Part of this ambivalence comes from the assumption that epigenetic inheritance is only relevant to the evolution of plants, which is perpetuated by a comparative lack of evolutionary studies in animals. However, although most of the evidence for epigenetic inheritance comes from plants, plants and animals share many homologous epigenetic mechanisms, and plants provide a more tractable system for investigating the causal role of epigenetic mechanisms underlying phenotypic variation and its relationship with fitness. The insights from studies of epigenetic inheritance in plants may be applicable across a broad range of taxa once we establish commonalities and differences in epigenetic machinery. In this paper we present evidence for a role of epigenetic mechanisms in the evolutionary process and discuss common objections to incorporating epigenetics into evolutionary theory. This review is not exhaustive, but is meant to demonstrate that epigenetic inheritance can be incorporated into current evolutionary theory without overhauling its foundations.