The adaptive significance of phenotypic changes elicited by environmental conditions experienced early in life has long attracted attention in evolutionary biology. In this study, we used Drosophila melanogaster to test whether the developmental diet produces phenotypes better adapted to cope with similar nutritional conditions later in life. To discriminate among competing hypotheses on the underlying nature of developmental plasticity, we employed a full factorial design with several developmental and adult diets. Specifically, we examined the effects of early- and late-life diets (by varying their yeast and sugar contents) on reproductive fitness and on the amount of energy reserves (fat and glycogen) in two wild-caught populations. We found that individuals that had developed on either low-yeast or high-sugar diet showed decreased reproductive performance regardless of their adult nutritional environment. The lower reproductive fitness might be caused by smaller body size and reduced ovariole number. Overall, these results are consistent with the silver spoon concept, which posits that development in a suboptimal environment negatively affects fitness-associated traits. On the other hand, the higher amount of energy reserves (fat) in individuals that had developed in a suboptimal environment might represent either an adaptive response or a side-effect of compensatory feeding. Our findings suggest that the observed differences in the adult physiology induced by early-life diet likely result from inevitable and general effects of nutrition on the development of reproductive and metabolic organs, rather than from adaptive mechanisms.

中文翻译：

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发育饮食对果蝇繁殖和代谢的影响。

由生命早期经历的环境条件引起的表型变化的适应性意义长期以来一直引起进化生物学的关注。在这项研究中，我们使用黑腹果蝇来测试发育饮食是否会产生更好地适应以后生活中类似营养状况的表型。为了区分关于发育可塑性的潜在性质的竞争假设，我们采用了几种发育和成人饮食的全因子设计。具体来说，我们研究了早期和晚期饮食（通过改变它们的酵母和糖含量）对两个野生捕捞种群的生殖健康和能量储备量（脂肪和糖原）的影响。我们发现，无论成年后的营养环境如何，在低酵母或高糖饮食中发育的个体的生殖能力都会下降。较低的生殖健康可能是由较小的体型和减少的卵巢数量引起的。总体而言，这些结果与银勺概念一致，该概念假设在次优环境中的发展会对与健康相关的特征产生负面影响。另一方面，在次优环境中发育的个体较高的能量储备（脂肪）可能代表适应性反应或补偿性喂养的副作用。