Data from: Reproductive and post-reproductive life history of wild-caught Drosophila melanogaster under laboratory conditions

The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random ‘add-on’ at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation.黑腹果蝇（Drosophila melanogaster）的生活史已得到充分解析，但学界极少通过追踪单一个体的全生命周期来测定其适合度组分（fitness components），这限制了对终生繁殖成功、生殖衰老（reproductive senescence）及生殖后寿命（post-reproductive lifespan）的认知。此外，多数现有研究以长期传代的实验室品系为研究对象，而非野外新捕获的个体，因此可能因果蝇适应实验室饲养环境、近交（inbreeding）或突变积累（mutation accumulation）而产生实验混淆。本研究追踪了源自3个新近捕获、未适应实验室环境的黑腹果蝇野生种群的雌性个体生活史。结果显示，不同种群在多项生活史性状上存在显著差异，包括卵巢小管数（ovariole number）、繁殖力（fecundity）、孵化率（hatchability）与寿命。为描述个体的年龄特异性繁殖力（age-specific fecundity）模式，我们开发了一种全新模型，可将雌性个体的生命划分为四个阶段：生殖成熟（reproductive maturation）阶段，随后依次为繁殖力的线性下降期与指数下降期，最终进入产卵后期（post-ovipository period）。单个雌性个体展现出清晰的繁殖力峰值，这与既往研究结论存在明显差异；且峰值后的繁殖力下降速率与雌性个体的寿命长短无关。值得注意的是，雌性个体拥有显著的生殖后寿命，平均占总寿命的40%。不同种群间的生殖后寿命并无显著差异，且与繁殖适合度组分无相关性，这支持如下假说：该阶段是繁殖生命末期高度可变的随机"附加阶段"，而非与繁殖适合度选择相关的性状。多数生活史性状呈正相关，这一模式可能源于野生果蝇被引入全新实验室环境后产生的基因型-环境互作（genotype by environment interactions），但不太可能由近交或突变积累引发的正向突变协方差（mutational covariance）所解释。