Developmental origins of adult function and health: Evolutionary hypotheses

Many biological systems have critical periods that overlap with the age of maternal provisioning via placenta or lactation. As such, they serve as conduits for phenotypic information transfer between generations and link maternal experience with offspring biology and disease outcomes. This review critically evaluates proposals for an adaptive function of these responses in humans. Although most models assume an adult function for the metabolic responses to nutritional stress, these specific traits have more likely been tailored for effects during fetal life and infancy. Other biological functions are under stronger evolutionary selection later in life and thus are better candidates for predictive plasticity. Given the long human life cycle and environmental changes that are unpredictable on decadal timescales, plastic responses that evolved to confer benefits in adolescence or adulthood likely rely on cues that integrate matrilineal experiences prior to gestation. We conclude with strategies for testing the timescale and adaptive significance of developmental responses to early environments.