Epigenetics in invasive species. Because invasive species are able to adapt to novel, sometimes stressful environments with limited genetic variation or through hybridization, epigenetic effects could be an important source of phenotypic variation (Bossdorf, Richards & Pigliucci 2008 Ecology Letters). Several recent studies have demonstrated that epigenetic effects can be altered in response to extreme environmental stress and that epigenetic processes are an important component of hybridization events. Working in Massimo Pigliucci’s lab at Stony Brook University, we showed that several invasive Fallopia populations have invaded novel salt marsh habitat with virtually no AFLP diversity, but maintain extensive phenotypic variation under greenhouse (Richards et al. 2008 AJB) and field conditions (Richards & Pigliucci in review). Therefore, epigenetic effects may be an important source of variation and Fallopia could be a model system for the study of epigenetic differentiation in the evolution of invasiveness. Understanding the degree and structure of epigenetic variation could help to explain how this and other plants invade novel habitats. I am pursuing this with an extensive survey of methylation sensitive AFLP (Richards, Bailey & Pigliucci in progress).

Experimental epigenetics in Arabidopsis. My colleagues and I have also recently completed a study on Arabidopsis thaliana, which demonstrates that response to nutrient environment by different ecotypes is affected by manipulating methylation with 5-aza-cytidine.  This response is dramatic considering that some ecotypes respond positively, while others respond negatively, to artificial demethylation (Bossdorf et al. in prep). We suspect, therefore, that natural epigenetic variation may play a key role in the ecology and evolution of plant species and that experiments should be designed to investigate this role (Bossdorf, Richards and Pigliucci 2008).

What role, if any, does heritable epigenetic variation play in phenotypic evolution? NESCent catalysis meeting April 1-3 2009 organized by Richards, Bossdorf and Pigliucci. To advance our understanding of the ecological and evolutionary relevance of heritable epigenetic variation, this meeting will bring together (1) molecular biologists studying epigenetic processes, (2) evolutionary ecologists with expertise in the experimental study of phenotypic variation and evolution in wild populations, and (3) theoretical population and quantitative geneticists that are experienced in the modeling of evolutionary processes. The aim of the meeting is to explore the phenomenon of inherited epigenetic variation from different perspectives, discuss possibilities for collaborative research between molecular biologists and evolutionary ecologists, and work towards the development of a general research agenda for ecological and evolutionary epigenetics.