Levine Brenna A, Schuett Gordon W, Clark Rulon W, Repp Roger A, Herrmann Hans-Werner, Booth Warren
Department of Biological Science, The University of Tulsa, Tulsa, OK 74104, USA.
The Chiricahua Desert Museum, Rodeo, NM 88056, USA.
R Soc Open Sci. 2020 Oct 7;7(10):201261. doi: 10.1098/rsos.201261. eCollection 2020 Oct.
Decades of research on sexual selection have demonstrated that 'conventional' Darwinian sex roles are common in species with anisogamous gametes, with those species often exhibiting male-biased sexual selection. Yet, mating system characteristics such as long-term sperm storage and polyandry have the capacity to disrupt this pattern. Here, these ideas were explored by quantifying sexual selection metrics for the western diamond-backed rattlesnake (). A significant standardized sexual selection gradient was not found for males ( = 0.588, = 0.199) or females ( = 0.151, = 0.664), and opportunities for sexual selection ( ) and selection () did not differ between males ( = 0.069, = 0.360) and females ( = 0.284, = 0.424; both > 0.05). Furthermore, the sexes did not differ in the maximum intensity of precopulatory sexual selection (males: = 0.155, females: = 0.080; > 0.05). Finally, there was no evidence that male snout-vent length, a trait associated with mating advantage, is a target of sexual selection ( > 0.05). These results suggest a lack of male-biased sexual selection in this population. Mating system characteristics that could erode male-biased sexual selection, despite the presence of conventional Darwinian sex roles, are discussed.
数十年来对性选择的研究表明，“传统的”达尔文性别角色在具有异形配子的物种中很常见，这些物种通常表现出雄性偏向的性选择。然而，诸如长期精子储存和一妻多夫制等交配系统特征有能力打破这种模式。在此，通过量化西部菱斑响尾蛇的性选择指标来探究这些观点。未发现雄性（= 0.588，= 0.199）或雌性（= 0.151，= 0.664）存在显著的标准化性选择梯度，并且雄性（= 0.069，= 0.360）和雌性（= 0.284，= 0.424；两者均> 0.05）之间的性选择机会（）和选择（）没有差异。此外，在交配前性选择的最大强度方面，两性没有差异（雄性：= 0.155，雌性：= 0.080；> 0.05）。最后，没有证据表明与交配优势相关的雄性吻肛长度是性选择的目标（> 0.05）。这些结果表明该种群中不存在雄性偏向的性选择。本文讨论了尽管存在传统的达尔文性别角色，但可能削弱雄性偏向性选择的交配系统特征。
