Data from: Sex-specific fitness consequences of nutrient intake and the evolvability of diet preferences

The acquisition of nutrients is fundamental for the maintenance of bodily functions, growth, and reproduction in animals. As a result, fitness can be maximized only when animals are able to direct their attention to foods that reflect their current nutritional needs. Despite significant literature documenting the fitness consequences of nutrient composition and preference, less is known about the underlying genetic architecture of the dietary preferences themselves, specifically, the degree to which they can respond to selection. We addressed this by integrating evolutionary quantitative genetics and nutritional geometry to examine the shape of the sex-specific fitness surfaces and the availability of genetic variance for macronutrient preferences in the fruit fly Drosophila melanogaster. Combining these analyses, we found that the microevolutionary potential of carbohydrate and protein preference was above average in this population, because the expected direction of selection was relatively well aligned with the major axis of the genetic variance-covariance matrix, G. We also found that potential exists for sexually antagonistic genetic constraint in this system; macronutrient blends maximizing fitness differed between the sexes, and cross-sex genetic correlations for their consumption were positive. However, both sexes were displaced from their feeding optima, generating similar directional selection on males and females, with the combined effect being that minimal sex-specific genetic constraints currently affect dietary preferences in this population.

养分获取是维持动物机体功能、生长与繁殖的基础。唯有当动物能够将注意力导向契合当前营养需求的食物时，其适合度才能达到最大化。尽管已有大量文献阐释了营养成分与饮食偏好对适合度的影响，但针对饮食偏好自身的潜在遗传结构——尤其是其对选择的响应程度——的研究仍相对匮乏。
本研究通过整合进化数量遗传学与营养几何学，以黑腹果蝇（Drosophila melanogaster）为实验对象，探究了性特异性适合度曲面的形态，以及宏量营养素偏好的遗传方差可利用性。综合上述分析，我们发现该种群中碳水化合物与蛋白质偏好的微进化潜力高于平均水平，这是因为预期的选择方向与遗传方差-协方差矩阵G的主轴契合度较高。
我们还发现该系统中存在性拮抗遗传约束的潜力：不同性别最大化适合度的宏量营养素配比存在差异，且二者取食行为的跨性别遗传相关为正值。然而，两性均偏离了各自的取食最适点，这对雌雄个体产生了相似的定向选择，综合效应为当前该种群的饮食偏好仅受到极弱的性特异性遗传约束。