The role of epigenetics in plant adaptation

Recent work in the field of plant epigenetics is adding to a growing understanding of how epigenetic variation can be an important source of phenotypic variation in natural populations. Therefore, it has the potential to play a major role in adaptation to environmental change. Most epigenetic variation is reset between generations, however, in some instances environmentally-induced epigenetic variation can result in heritable phenotypic plasticity that invokes Lamarkian-like inheritance. Epigenetic variation can also be the result of random epimutations that can have both higher mutation and reversal rates than DNA sequence mutations. We discuss several examples documenting epigenetic variation in wild populations. We also discuss laboratory studies that investigate the rate of epimutations and reversals, and how that has been incorporated into evolutionary theory. We suggest that modern evolutionary theory will benefit from the incorporation of epigenetics, but it is not in need of a complete revision, as has been suggested.