Data from: Incorporating an ontogenetic perspective into evolutionary theory of sexual size dimorphism

Sexual size dimorphism (SSD) describes divergent body sizes of adult males and females. While SSD has traditionally been explained by sexual and fecundity selection, recent advances in physiology and developmental biology emphasize that SSD would occur proximately because of sexual differences in ontogenetic growth trajectories (i.e., growth rate and duration). Notably, these ontogenetic traits are subject to energetic or time constraints and thus traded off with fitness components (e.g., survival and reproduction). To elucidate the importance of such ontogenetic trade-offs in the evolution of SSD, we developed a new theoretical framework by extending quantitative genetic models for the evolution of sexual dimorphism in which we reinterpret the trait as body size and reformulate sex-specific fitness in size-dependent manners. More specifically, we assume that higher growth rate or longer growth duration leads to larger body size and higher reproductive success but incurs the cost of lower survivorship or shorter reproduction period. We illustrate how two sexes would optimize ontogenetic growth trajectories in sex-specific ways and exhibit divergent body sizes. The present framework provides new insights into the evolutionary theory of SSD and predictions for empirical testing.性体型二态性（Sexual size dimorphism, SSD）指成年雌雄个体间存在的体型差异。尽管传统观点认为性体型二态性由性选择与繁殖力选择所塑造，但近年来生理学与发育生物学的研究进展表明，其直接成因源于两性在个体发育生长轨迹（即生长速率与生长持续时间）上的差异。值得注意的是，此类个体发育性状受能量或时间限制，因此与适合度组分（如生存与繁殖）存在进化权衡。为阐明此类个体发育权衡在性体型二态性演化中的重要性，本研究通过拓展性二态性演化的数量遗传模型，构建了全新的理论框架：我们将该性状重新诠释为体型，并以体型依赖的方式重新定义了性别特异性适合度。具体而言，我们假设更高的生长速率或更长的生长持续时间可使个体体型更大、繁殖成功率更高，但同时会付出存活率降低或繁殖周期缩短的代价。我们演示了两性如何以性别特异性的方式优化个体发育生长轨迹，并最终形成体型差异。本框架为性体型二态性的演化理论提供了全新视角，并可为实证检验提供可验证的预测依据。