2016年2月22日，国际知名学术期刊《PLOS ONE》在线发表中国科学院成都生物研究所崔建国博士发表锯腿小树蛙对配偶身体大小选择偏好的研究论文，研究表明雌性锯腿小树蛙偏好中等大小的雄性，并不是越大越好。唐业忠课题组朱弼成为论文共同第一作者，崔建国博士为论文通讯作者。

传统的性选择理论认为大个体雄性在雄性竞争和雌性选择中占有优势，性选择倾向于更大的雄性，这方面的实验证据很多。然而，关于性选择限制雄性身体大小的证据却寥寥无几。从求偶场到繁殖场，雌性锯腿小树蛙(Philautus odontotarsus)需要背负雄性配偶相对较长的距离。背负大个体雄性意味着要消耗更多的能量，雌蛙的活动敏捷性也会随之降低，被捕食的风险增高。因此我们推测雌性的背负代价是一种限制雄性身体大小进化的选择压力，并提出假设雌蛙不会选择大个体的雄性。

自然条件下，无尾两栖类主要通过鸣叫的方式求偶，因此必须用雌性趋声的方法验证其对配偶身体大小的偏好选择规律。实验分为以下三步：1)分析锯腿小树蛙身体大小与鸣叫结构的相关性，发现其广告鸣叫的主频与体重呈负相关性;2)制作高中低三个不同主频的刺激音频，进行雌性趋声性实验，结果证明不同体重的雌蛙均偏好选择中等主频的广告鸣叫(对应中等大小体重)，暗示雌性锯腿小树蛙偏好中等大小的雄性;3)比较自然条件下成功抱对雄蛙和未抱对雄蛙的体重分布情况，发现成功抱对雄蛙的体重更集中于中间水平，印证了趋声性实验结果。

文章首次揭示了大个体雄蛙在繁殖成功上没有优势，并证明雌性选择限制了雄性体重向更夸张的方向进化，稳定选择导致种群中中等大小的雄性居多，对性选择理论做了新的补充。

原文摘要：Most species are believed to evolve larger body sizes over evolutionary time. Previous studies have suggested that sexual selection, through male-male competition and female choice, favors larger males. However, there is little evidence of selection against large size. The female serrate-legged small treefrogs (Philautus odontotarsus) must carry passive males from leks to breeding grounds over relatively long distances after amplexus to find a suitable place to lay eggs. The costs of large male size may therefore decrease mating success due to reduced agility and/or higher energy requirements. Thus, we hypothesized that selection would not favor larger males in P. odontotarsus. Females can assess male body size on the basis of the dominant frequency of male calls in frogs. To assess female P. odontotarsus preferences for a potential mate’s body size, male calls of high, average and low dominant frequency were played back to the females in phonotaxis experiments. Results showed that most females prefer the advertisement call with average dominant frequency. In addition, we compared the body mass distribution of amplectant males with that of single males in nature. The body masses of amplectant males are more narrowly distributed in the intermediate range than that of single males. The phonotaxis results and the data of actual female preferences in the field show that females strongly prefer potential mates of mean body sizes, consistent with the view that, in this species at least, larger males are not always perceived as better by females. In the present study, P. odontotarsus provides an example of an amphibian species in which large size does not have an advantage in mating success for males. Instead, our results provide evidences that stabilizing selection favors the optimal intermediate size of males.