This is prompted by niallhaslam's answer to this question [Since Darwinian times, has there been any striking/notable effects of evolution on humans?]. A comment by Alan Boyd asks whether epigenetic changes count as evolution.
Transgenerational epigenetic inheritance can occur, and does increase the natural variation of a species (although this review is more about plants, this does apply to animals too) . Based on this alone I'm inclined to say that epigenetics can affect the fitness of a species, and thus could contribute to evolution.
I am interested to know if, in practise, this does occur, and whether epigenetics have been shown to affect the reproductive success of a species? Because the changes are not permanent I could imagine that they actually have very little impact "species-wide", as environmental effects (infections, toxic exposures) also affect epigenetics. So, is there any evidence for epigenetics affecting the reproductive success of a species? This also includes whether epigenetics can influence traits enough to create a new sub-species.
- Becker, C., & Weigel, D. (2012). Epigenetic variation: origin and transgenerational inheritance. Current opinion in plant biology. doi:10.1016/j.pbi.2012.08.004.