We are interested in determining how phenotypic plasticity and diversity are driven by natural and spontaneous epigenetic variation. Recent advances in genomic technologies are enabling acquisition of sequence-level data at an unprecedented rate and resolution. As a result, genomes for thousands of individuals are being analyzed to determine the total genetic variation present within a species and to determine the impact these variants have on phenotypic variation. Missing from these efforts is the identification of environmentally induced, spontaneous and natural epigenetic alleles (epialleles). We apply epigenomic approaches to populations to study the impact that epialleles have on life history traits and to understand their role in establishing responses to the environment. These epialleles are often associated with changes in their DNA methylation status making their identification possible. Systematically identifying these epialleles, understanding their patterns of heritability, their interaction with genetic variants and their specific roles in controlling gene expression is necessary for a comprehensive understanding of phenotypic variation.