Department of Biological Sciences, Ohio Wesleyan University, Delaware, OH 43015, USA.
Department of Evolutionary Biology, San Diego State University, San Diego, CA 92182, USA.
J Exp Biol. 2024 Sep 15;227(18). doi: 10.1242/jeb.248014. Epub 2024 Sep 20.
An animal's morphology influences its ability to perform essential tasks, such as locomoting to obtain prey or escape predators. While morphology-performance relationships are well-studied in lizards, most conclusions have been based only on male study subjects, leaving unanswered questions about females. Sex-specific differences are important to understand because females carry the bulk of the physiological demands of reproduction. Consequently, their health and survival can determine the fate of the population as a whole. To address this knowledge gap, we sampled introduced populations of common wall lizards (Podarcis muralis) in Ohio, USA. We measured a complete suite of limb and body dimensions of both males and females, and we measured sprint speeds while following straight and curved paths on different substrates. Using a multivariate statistical approach, we identified that body dimensions relative to snout-to-vent length in males were much larger compared with females and that body dimensions of P. muralis have changed over time in both sexes. We found that sprint speed along curved paths increased with relative limb size in both males and females. When following straight paths, male speed similarly increased as body dimensions increased; conversely, female speed decreased as body dimensions increased. Female sprint speed was also found to have less variation than that of males and was less affected by changes in body size and hindfoot length compared with males. This study thus provides insights into how selective pressures might shape males and females differently and the functional implications of sexual dimorphism.
动物的形态结构会影响其完成基本任务的能力，例如移动以获取猎物或逃避捕食者。虽然蜥蜴的形态与性能关系已经得到了充分研究，但大多数结论仅基于雄性研究对象，而雌性的问题仍未得到解答。性别特异性差异很重要，因为雌性承担着繁殖过程中大部分的生理需求。因此，它们的健康和生存可以决定整个种群的命运。为了解决这一知识空白，我们在美国俄亥俄州采集了引入的普通壁蜥（Podarcis muralis）种群。我们测量了雄性和雌性的肢体和身体尺寸的完整套件，并在不同基质上沿着直线和曲线跟踪时测量了冲刺速度。使用多元统计方法，我们确定了雄性的身体尺寸相对于吻肛长的比例与雌性相比要大得多，并且 P. muralis 的身体尺寸在两性中都随时间发生了变化。我们发现，雄性和雌性在曲线路径上的冲刺速度都随相对肢体尺寸的增加而增加。当沿着直线路径追踪时，雄性的速度随着身体尺寸的增加而相似增加；相反，雌性的速度随着身体尺寸的增加而减小。还发现，雌性的冲刺速度比雄性的变化更小，并且与雄性相比，身体尺寸和后足长度的变化对其影响较小。因此，这项研究深入了解了选择压力如何以不同的方式塑造雄性和雌性，以及性别二态性的功能意义。
