Pipoly Ivett, Bókony Veronika, Gaillard Jean-Michel, Lemaître Jean-François, Székely Tamás, Liker András
HUN-REN-PE Evolutionary Ecology Research Group, University of Pannonia, Veszprém, Hungary.
Behavioral Ecology Research Group, Center for Natural Sciences, Faculty of Engineering, University of Pannonia, Veszprém, Hungary.
PLoS Biol. 2025 May 12;23(5):e3003156. doi: 10.1371/journal.pbio.3003156. eCollection 2025 May.
Sex chromosomes can determine male and female phenotypes, and the resulting sex differences may have significant impacts on ecology and life history. One manifestation of this link is that ZW/ZZ sex-determination systems are associated with more male-skewed adult sex ratio (ASR, proportion of males in the adult population) than XX/XY systems across tetrapods (amphibians, reptiles, birds, and mammals). Here, we investigate four demographic processes: male and female offspring production, sex differences in juvenile and adult mortalities and in timing of maturation that can contribute to ASR variation between XX/XY and ZW/ZZ systems, using phylogenetic analyses of a large dataset collected from tetrapod species in the wild. We show that sex differences in adult mortality reliably predict ASR that is also more male-biased in XX/XY species than in ZW/ZZ species. Sex differences in juvenile mortality and in maturation time also contribute to ASR skews, but do not differ consistently between XX/XY and ZW/ZZ systems. Phylogenetic path analyses confirm an influence of sex-determination system on ASR through sex-biased adult mortalities. Together these results infer that sex chromosomes can impact, via demographic pathways, frequency-dependent selection emerging from the relative number of males and females. We call for follow-up studies to uncover the potentially complex web of associations between sex determination, population dynamics, and social behavior.
性染色体能够决定雄性和雌性表型，而由此产生的性别差异可能会对生态和生活史产生重大影响。这种联系的一种表现是，在四足动物（两栖动物、爬行动物、鸟类和哺乳动物）中，ZW/ZZ性别决定系统比XX/XY系统与更偏向雄性的成年性别比（ASR，成年种群中雄性的比例）相关联。在这里，我们研究了四个种群统计学过程：雄性和雌性后代的产生、幼年和成年死亡率的性别差异以及成熟时间的差异，这些过程可能导致XX/XY和ZW/ZZ系统之间的ASR变化，我们使用从野生四足动物物种收集的大型数据集进行系统发育分析。我们表明，成年死亡率的性别差异能够可靠地预测ASR，并且在XX/XY物种中ASR比ZW/ZZ物种中更偏向雄性。幼年死亡率和成熟时间的性别差异也会导致ASR偏差，但在XX/XY和ZW/ZZ系统之间并没有一致的差异。系统发育路径分析证实了性别决定系统通过偏向性别的成年死亡率对ASR产生影响。这些结果共同推断，性染色体可以通过种群统计学途径影响由雄性和雌性相对数量产生的频率依赖选择。我们呼吁开展后续研究，以揭示性别决定、种群动态和社会行为之间潜在的复杂关联网络。
