Abstract
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 (Crotalus atrox). A significant standardized sexual selection gradient was not found for males (β SS = 0.588, p = 0.199) or females (β SS = 0.151, p = 0.664), and opportunities for sexual selection (I s) and selection (I) did not differ between males (I s = 0.069, I = 0.360) and females (I s = 0.284, I = 0.424; both p > 0.05). Furthermore, the sexes did not differ in the maximum intensity of precopulatory sexual selection (males: s′ max = 0.155, females: s′ max = 0.080; p > 0.05). Finally, there was no evidence that male snout-vent length, a trait associated with mating advantage, is a target of sexual selection (p > 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.
Original language | English |
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Article number | 201261 |
Journal | Royal Society Open Science |
Volume | 7 |
Issue number | 10 |
DOIs | |
State | Published - 1 Oct 2020 |
Keywords
- Bateman principles
- Crotalus atrox
- anisogamy
- mating system
- rattlesnake
- reproductive success