Data from: Ontogenetic timing as a condition-dependent life history trait: high-condition males develop quickly, peak early and age fast

Within-population variation in ageing remains poorly understood. In males, condition-dependent investment in secondary sexual traits may incur costs which limit ability to invest in somatic maintenance. Moreover, males often express morphological and behavioural secondary sexual traits simultaneously, but the relative effects on ageing of investment in these traits remain unclear. We investigated the condition-dependence of male life history in the neriid fly Telostylinus angusticollis. Using a fully factorial design, we manipulated male early-life condition by varying nutrient content of the larval diet and, subsequently, manipulated opportunity for adult males to interact with rival males. We found that high-condition males developed more quickly and reached their reproductive peak earlier in life, but also experienced faster reproductive ageing and died sooner than low-condition males. By contrast, interactions with rival males reduced male lifespan but did not affect male reproductive ageing. High condition in early life is therefore associated with rapid ageing in T. angusticollis males, even in the absence of damaging male-male interactions. Our results show that abundant resources during the juvenile phase are used to expedite growth and development and enhance early-life reproductive performance at the expense of late-life performance and survival, demonstrating a clear link between male condition and ageing.种群内部的衰老差异仍未得到充分解析。在雄性个体中，对第二性征的条件依赖性投入往往会产生相应代价，进而限制其在体细胞维持方面的投入能力。此外，雄性通常同时展现形态学与行为学层面的第二性征，但目前尚不明确对这些特征的投入对衰老的相对影响程度。本研究以窄眼蝇科（Neriidae）昆虫宽颈窄眼蝇（Telostylinus angusticollis）为实验材料，探究了雄性生活史的条件依赖性特征。研究采用完全析因设计，通过改变幼虫饲料的营养含量来调控雄性个体的早期发育条件，并在此后调控成年雄性与同性竞争对手互动的机会。结果显示，发育条件优越的雄性个体发育速度更快，且在生命早期即达到生殖峰值，但相较于发育条件较差的雄性，其生殖衰老速度更快、寿命更短。与之形成鲜明对比的是，与竞争对手的互动仅缩短了雄性的寿命，并未对其生殖衰老进程产生影响。因此，即便不存在具有伤害性的雄性间互作，宽颈窄眼蝇雄性的早期优越发育条件仍与其快速衰老密切相关。本研究结果表明，幼年阶段获取的充足资源会被用于加速生长发育并提升早期生殖表现，却以后期生理表现与生存能力为代价，清晰揭示了雄性个体发育条件与衰老之间的内在关联。