The effects of selective history and environmental heterogeneity on inbreeding depression in experimental populations of Drosophila melanogaster

Inbreeding depression varies considerably among populations, but only some aspects of this variation have been thoroughly studied. Because inbreeding depression requires genetic variation, factors that influence the amount of standing variation can affect the magnitude of inbreeding depression. Environmental heterogeneity has long been considered an important contributor to the maintenance of genetic variation, but its effects on inbreeding depression have been largely ignored by empiricists. Here we compare inbreeding depression, measured in two environments, for 20 experimental populations of Drosophila melanogaster that have been maintained under four different selection regimes, including two types of environmentally homogeneous selection and two types environmentally heterogeneous selection. In line with theory, we find considerably higher inbreeding depression in populations from heterogeneous selection regimes. We also use our data set to test whether inbreeding depression is cor...

近交衰退（inbreeding depression）在不同种群间差异显著，但目前仅对该差异的部分方面开展了深入研究。由于近交衰退的发生依赖于遗传变异，因此影响现存遗传变异总量的各类因素，均可对近交衰退的强度产生影响。长期以来，环境异质性被视作维持遗传变异的关键因素，但其对近交衰退的影响却在很大程度上被实验研究者所忽视。本文针对20个经四种不同选择方案（selection regimes）长期维持的黑腹果蝇（Drosophila melanogaster）实验种群展开研究，该四种选择方案包括两种环境均质选择与两种环境异质选择，并对比了两种环境下测得的近交衰退水平。与理论预期一致，我们发现源自异质选择方案种群的近交衰退程度显著更高。此外，我们还利用本数据集检验近交衰退是否与……