Variation in body size and sexual size dimorphism in the most widely-ranging lizard: testing the effects of reproductive mode and climate

Reproductive mode, ancestry, and climate are hypothesized to determine body-size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species’ range we analysed how sex-specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south-western France) exhibited a smaller female size and ...已有假说提出繁殖模式、谱系背景与气候共同决定爬行动物的体型变异，但相关效应鲜少被同时估算，尤其是在种内层面。胎生蜥蜴（Zootoca vivipara）几乎遍布整个北欧亚大陆，且包含胎生（viviparous）与卵生（oviparous）两大演化支系，因此是开展此类研究的理想模型类群。本研究依托该物种分布范围内72个地理隔离种群的逾10000条个体体长数据，分析了成体性别特异性体型与性别体型二态性（sexual size dimorphism, SSD）与繁殖模式、谱系归属以及多项气候变量之间的关联。雄性体型的变异程度较低，且其变异难以通过本研究的预测变量予以解释。与之相反，雌性体型与SSD的变异程度显著，显示繁殖模式尤其是季节性对其存在显著影响。西部卵生支系的种群（西班牙北部、法国西南部）展现出更小的雌性体型及……