University of Sydney, School of Biological Sciences, Heydon-Lawrence Building, AO8, NSW 2006, Australia.
Evolution. 2011 Feb;65(2):574-83. doi: 10.1111/j.1558-5646.2010.01152.x. Epub 2010 Nov 5.
A changing climate is expected to have profound effects on many aspects of ectotherm biology. We report on a decade-long study of free-ranging sand lizards (Lacerta agilis), exposed to an increasing mean mating season temperature and with known operational sex ratios. We assessed year-to-year variation in sexual selection on body size and postcopulatory sperm competition and cryptic female choice. Higher temperature was not linked to strength of sexual selection on body mass, but operational sex ratio (more males) did increase the strength of sexual selection on body size. Elevated temperature increased mating rate and number of sires per clutch with positive effects on offspring fitness. In years when the "quality" of a female's partners was more variable (in standard errors of a male sexual ornament), clutches showed less multiple paternity. This agrees with prior laboratory trials in which females exercised stronger cryptic female choice when male quality varied more. An increased number of sires contributing to within-clutch paternity decreased the risk of having malformed offspring. Ultimately, such variation may contribute to highly dynamic and shifting selection mosaics in the wild, with potential implications for the evolutionary ecology of mating systems and population responses to rapidly changing environmental conditions.
气候变化预计将对许多变温动物生物学的方面产生深远的影响。我们报告了一项长达十年的对自由生活的沙蜥蜴（Lacerta agilis）的研究，这些蜥蜴暴露在不断升高的平均交配季节温度下，并且具有已知的实际性别比例。我们评估了身体大小和交配后精子竞争及隐蔽性雌性选择的年度间的性选择变化。较高的温度与身体质量的性选择强度没有联系，但实际性别比例（更多雄性）确实增加了身体大小的性选择强度。升高的温度增加了交配率和每窝的亲代数量，对后代的适应性有积极影响。在雌性伴侣“质量”变化更大的年份（雄性性装饰的标准误差中），窝卵数显示出较少的多父性。这与先前的实验室试验结果一致，即当雄性质量变化更大时，雌性会表现出更强的隐蔽性雌性选择。增加为窝内亲代做出贡献的亲代数量降低了产生畸形后代的风险。最终，这种变化可能导致在野外高度动态和变化的选择镶嵌体，这可能对交配系统的进化生态学和对快速变化的环境条件的种群反应产生影响。
