Problem
• Various environmental factors, such as diet/nutrition, parental care, and social interaction have been shown to influence the epigenome and ultimately behavior in many different species, including insects, rodents, and humans. Choose a specific behavior that probably evolved biologically but varies in different people. Suggest at least one environmental factor that could account for variation in this behavior. Is there evidence to support an epigenetic link to variations in this behavior?
• Gene by environment interactions (or gene x environment interactions) are ways in which specific genotypes, after exposure to different environmental factors, show variation in the phenotype. For example, different alleles of the serotonin transporter are associated with individual stress susceptibility and risk of developing mood-related disorders (e.g., depression, anxiety). Why do you think the environment can modulate genes associated with brain structure and function? Comment on whether these interactions evolved to enhance our survival.