Data from: Nutrition shapes life-history evolution across species

Nutrition is a key component of life-history theory, yet we know little about how diet quality shapes life-history evolution across species. Here, we test whether quantitative measures of nutrition are linked to life-history evolution across 96 species of butterflies representing over 50 independent diet shifts. We find that butterflies feeding on high nitrogen host plants as larvae are more fecund, but their eggs are smaller relative to their body size. Nitrogen and sodium content of host plants are also both positively related to eye size. Some of these relationships show pronounced lineage-specific effects. Testis size is not related to nutrition. Additionally, the evolutionary timing of diet shifts is not important, suggesting that nutrition affects life histories regardless of the length of time a species has been adapting to its diet. Our results suggest that, at least for some lineages, species with higher nutrient diets can invest in a range of fitness-related traits like fecundity and eye size while allocating less to each egg as offspring have access to a richer diet. These results have important implications for the evolution of life histories in the face of anthropogenic changes in nutrient availability.营养是生活史理论（life-history theory）的核心组成部分，但目前学界对饮食质量如何塑造跨物种的生活史演化仍知之甚少。本研究针对涵盖50余次独立宿主饮食转变的96种蝴蝶，检验营养的量化指标是否与跨物种的生活史演化存在关联。研究发现，幼虫取食高氮宿主植物的蝴蝶繁殖力更强，但其所产卵的尺寸相对于体型而言更小；宿主植物的氮与钠含量均与蝴蝶复眼尺寸呈正相关。其中部分关联呈现出显著的谱系特异性效应，而睾丸尺寸则与营养水平并无关联。此外，饮食转变的演化时间节点并不影响上述关联，这表明无论物种适应其当前饮食的时长如何，营养均会对其生活史产生影响。本研究结果表明，至少在部分谱系中，取食高营养饮食的物种可在繁殖力、复眼尺寸等一系列适合度相关性状上投入更多资源，而由于后代可获取更为丰富的食物，其对单枚卵的资源分配则会减少。这些研究结果对人类活动导致营养可获得性改变背景下的生活史演化研究具有重要意义。