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.

营养获取是动物维持机体机能、生长发育与繁殖的核心基础。因此，唯有当动物能够将觅食注意力投向契合自身当前营养需求的食物时，其适合度（fitness）才能实现最大化。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，但针对饮食偏好本身的潜在遗传架构——尤其是其对选择压力的响应程度——的认知仍较为有限。本研究通过整合进化数量遗传学（evolutionary quantitative genetics）与营养几何学（nutritional geometry）方法，以黑腹果蝇（Drosophila melanogaster）为模式生物，探究了性特异性适合度曲面的形态特征，以及宏量营养素（macronutrient）偏好的遗传方差可利用性。通过整合上述分析结果，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（microevolutionary potential）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）的主轴高度吻合。此外，本研究还发现该系统中存在性拮抗遗传约束（sexually antagonistic genetic constraint）的潜在可能：两性间最大化适合度的宏量营养素混合物存在显著差异，且其摄食行为的跨性遗传相关（cross-sex genetic correlations）为正相关。但两性均偏离了其摄食最适点（feeding optima），这使得雄性与雌性受到了相似的定向选择（directional selection），综合效应为：当前该种群的饮食偏好受性特异性遗传约束的影响极小。