Data from: A general description of additive and non-additive elements of sperm competitiveness and their relation to male fertilization success

A complete understanding of male reproductive success, and thus sexual selection, often requires an insight into male success in sperm competition. Genuine conclusions on male sperm competitiveness can only be made in real competitive situations. However, statistical analyses of sperm competitiveness from fertilization success data have been shown to be problematic. Here, I first outline a comprehensive general description of the different additive and non-additive elements relevant for the outcome of sperm competition staged between two males. Based on this description, I will highlight two main problems that are frequently encountered in experiments aiming at estimating sperm competitiveness. First, I focus on potential problems when using standardized competitors vs. random mating trials, because trials with standardized competitors do not allow generalization if male-male interactions are important. Second, I illustrate the necessity to analyse data on the logit scale rather than on raw proportions, because only the logit scale allows a clean separation of additive and non-additive effects (i.e. male×male- and female×male interactions).

要全面认知雄性繁殖成功率，进而理解性选择，通常需要洞悉雄性在精子竞争（sperm competition）中的表现。唯有在真实的竞争场景中，才能得出关于雄性精子竞争力的严谨结论。然而，已有研究证实，基于受精成功率数据开展的精子竞争力统计分析存在诸多局限。本文首先系统梳理了与人为设置的两雄精子竞争结局相关的各类加性与非加性影响因子。基于上述梳理，本文将点明当前评估精子竞争力的实验中普遍存在的两大核心问题：其一，探讨采用标准化竞争者与随机交配试验时的潜在缺陷——若雄雄互作发挥关键作用，则使用标准化竞争者的试验无法实现研究结论的外推推广；其二，阐明相较于原始比例数据，在logit尺度（logit scale）下开展数据分析的必要性，因为唯有logit尺度能够清晰区分加性与非加性效应（即雄雄互作与雌雄互作效应）。