Patterns and determinants of geographic variation in adult body size and sexual size dimorphism in two widespread lizard species

系统发育的小影响和相当大范围的环境条件的有利组合，使分布广泛的物种种群之间的地理差异成为检验适应性假说的一个有前途的模型。然而，对分布广泛的物种的地理变异进行全面的全范围研究--即使是像体型这样根本上重要的特征--也很少见。在这个项目中，我将记录两种广泛分布和广域共生的蜥蜴物种--大蜥蜴和胎生动物在体型、性大小二型性和雌性生殖输出方面的宏观地理和区域模式。在仔细考虑潜在的混杂因素的情况下，我将调查这些模式与环境(气候)、与系统发育以及彼此之间的关系。特别是，达尔文的生育优势假说的几个预测将被检验，两个突出的和目前正在辩论的体型变化模式--伯格曼规则和伦施规则--将被讨论。

A favourable combination of a small effect of phylogeny and a considerable range of environmental conditions makes geographic variation among populations of widespread species a promising model for testing adaptive hypotheses. However, comprehensive range-wide studies of geographic variation in widespread species – even for so fundamentally important trait as body size - are rare. During this project I will document macrogeographic and regional patterns of variation in body size, sexual size dimorphism, and female reproductive output in two widely distributed and broadly sympatric lizard species, Lacerta agilis and Zootoca vivipara. Under careful consideration of potential confounding factors I will investigate relationships of these patterns with the environment (climate), with phylogeny, and among each other. In particular, several predictions of Darwin's fecundity-advantage hypothesis will be tested, and two prominent and currently debated patterns of body size variation, Bergmann’s rule and Rensch’s rule, will be addressed.