With genes and environments now operating in parallel to shape our RNA-driven bodies, the integration of those two streams of influence has become a central challenge in biological analyses of human health and behavior. The regulatory paradigm outlined in Figure 1 provides a framework for analyzing their interplay in the context of Gene x Environment interactions. For example, variations in the DNA sequence of the promoter regulating the serotonin transporter gene (5HTT) can affect the binding of environmentally sensitive transcription factors, and thereby buffer the effects of adverse social environments on the risk of depression and other affective behaviors (Caspi et al., 2003; Champoux et al., 2002). These effects extend into the realm of immune response and survival (Capitanio et al., 2008), and thus may also shape the evolutionary trajectory of our DNA genome at a population level. In integrating the molecular biology of gene structure, the environmental control of gene expression, and the social biology of individual behavior and survival, the 5HTT promoter polymorphism exemplifies the new “environmentally conscious” conception of genetics in which cellular and organismic behavior constitute
