Contribution of maternal effects to dietary selection in Mediterranean fruit flies.

Individual responses to dietary variation represent a fundamental component of fitness, and nutritional adaptation can occur over just a few generations. Maternal effects can show marked proximate responses to nutrition, but whether they contribute to longer-term dietary adaptation is unclear. Here we tested the hypotheses that maternal effects: (i) contribute to dietary adaptation, (ii) diminish when dietary conditions are constant between generations, (iii) are trait-specific and (iv) interact with high- and low-quality food. We used experimental evolution regimes in the medfly (Ceratitis capitata) to test these predictions by subjecting an outbred laboratory-adapted population to replicated experimental evolution on either constant high calorie sugar (‘A’) or low-calorie starch (‘S’) larval diets, with a standard adult diet across both regimes. We measured the contribution of maternal effects by comparing developmental and adult phenotypes of individuals reared on their own diet with...