gestation may last across the lifespan. Stable and long-lasting epigenetic alterations in the brain also has been suggested to cause some psychiatric disorders (Feinberg et al., 2007; Gardner et al. 2007; Simmons 2009), leading to the hypothesis that many adult diseases with epigenetic underpinnings have fetal origins (Bezek et al. 2008; Doherty et al. 2009). In this way, epigenetics may shape human behaviors, and environmental events may have heritable impact on the genes.
