Data for: Sexual Selection and the Non-random Union of Gametes: Retesting for Assortative Mating by Fitness in Drosophila melanogaster

While numerous theoretical population genetic models indicate that mating assortatively by genetic ‘quality’ in a species can enhance the efficiency of purging of deleterious mutations and/or the spread of beneficial alleles in the gene pool, empirical studies looking to quantify the extent of assortative mating by quality are surprisingly rare and largely inconclusive. Here, we set out to examine whether fruit flies (Drosophila melanogaster) engage in assortative mating by body-size phenotype, a composite trait strongly associated with both reproductive success and survival, and is considered a reliable indicator of natural genetic quality. Male and female flies of different body-size sizes classes (large and small) were obtained under the typical culture conditions to which they were adapted and placed into competitive reproductive conditions, so that their interactions and mating patterns could be measured. We found that flies engaged in assortative courting and mating behaviours and that they produced more offspring with similar sized individuals. Subsequent assays of offspring fitness indicated that assortative mating produced sons and daughters that had greater or equal reproductive success than those produced from disassortative mating. Together, these results validate theoretical predictions and demonstrate that assortative mating sexual selection can enhance the effects of natural selection and consequently the rate of adaptive evolution. The datasets archived here contain the observations on courtship rates, mating speeds, copulation durations, and offpring production that were obtained in our two sets of experiments. The data represents the results of experiments examining behaviour and reproductive success of fruit flies, Drosophila melanogaster. They are saved in .csv format.

尽管诸多理论种群遗传学模型均表明，物种中基于遗传‘质量’进行选型交配（assortative mating），可提升有害突变（deleterious mutation）清除的效率，并促进有益等位基因（beneficial allele）在基因库（gene pool）中的扩散，但旨在量化基于质量的选型交配程度的实证研究（empirical study）却极为稀少，且整体尚无定论。本研究旨在探究黑腹果蝇（Drosophila melanogaster）是否会基于体型表型（body-size phenotype）进行选型交配：体型作为一类与繁殖成功率（reproductive success）及生存能力均紧密相关的复合性状（composite trait），被视为自然遗传质量的可靠指示指标。我们在果蝇适应的标准培养条件下，获取了分为大型、小型两个体型等级的雌雄果蝇，并将其置于竞争性繁殖环境中，以观测其交互行为与交配模式。研究结果显示，果蝇会表现出选型求偶与交配行为，且与体型相近的个体交配时，其产生的后代数量更多。后续针对后代适合度（offspring fitness）的检测表明，通过选型交配产生的雌雄后代，其繁殖成功率均高于或等同于非选型交配（disassortative mating）所产生的后代。综上，本研究结果验证了相关理论预测，并证实选型交配这一性选择策略可强化自然选择的作用，进而提升适应性进化（adaptive evolution）的速率。本研究存档的数据集包含两项实验中获取的求偶率、交配速度、交尾持续时长以及后代产出量观测数据。该数据集涵盖了针对黑腹果蝇行为与繁殖成功率的实验结果，以.csv格式存储。