School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TU, UK.
Proc Biol Sci. 2021 Nov 24;288(1963):20211787. doi: 10.1098/rspb.2021.1787.
Dietary restriction (DR) improves survival across a wide range of taxa yet remains poorly understood. The key unresolved question is whether this evolutionarily conserved response to temporary lack of food is adaptive. Recent work suggests that early-life DR reduces survival and reproduction when nutrients subsequently become plentiful, thereby challenging adaptive explanations. A new hypothesis maintains that increased survival under DR results from reduced costs of overfeeding. We tested the adaptive value of DR response in an outbred population of fruit flies. We found that DR females did not suffer from reduced survival upon subsequent re-feeding and had increased reproduction and mating success compared to their continuously fully fed (FF) counterparts. The increase in post-DR reproductive performance was of sufficient magnitude that females experiencing early-life DR had the same total fecundity as continuously FF individuals. Our results suggest that the DR response is adaptive and increases fitness when temporary food shortages cease.
饮食限制（DR）改善了广泛的分类群的生存，但仍知之甚少。关键的未解决问题是，这种对暂时缺乏食物的进化保守反应是否具有适应性。最近的工作表明，早期 DR 会降低当营养物质随后变得丰富时的生存和繁殖能力，从而对适应性解释提出挑战。一个新的假设认为，DR 下的生存增加是由于过度喂养的成本降低所致。我们在一个杂交的果蝇种群中测试了 DR 反应的适应性价值。我们发现，DR 雌蝇在随后的重新喂养时并没有因生存能力降低而受到影响，并且与持续完全喂养（FF）的对应物相比，繁殖和交配成功率更高。DR 后生殖性能的提高幅度足以使经历早期 DR 的雌蝇与持续 FF 的个体具有相同的总生育率。我们的结果表明，当暂时的食物短缺停止时，DR 反应是适应性的，并能提高适应性。
