1
|
Richardson J, Zuk M. Meta-analytical evidence that males prefer virgin females. Ecol Lett 2024; 27:e14341. [PMID: 37988323 DOI: 10.1111/ele.14341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/23/2023]
Abstract
Males are often predicted to prefer virgin over non-virgin females because of the reduced risk of sperm competition. Does this prediction hold across studies? Our systematic meta-analysis of 138 studies, mainly conducted in invertebrates, confirms that males generally prefer virgin females. However, males preferred virgin females even in species with last male sperm precedence, suggesting that sperm competition alone does not drive male preferences. Furthermore, our results suggest that males may reject mated females even when no alternative exists. Preference for virgins is unlikely to influence female reproductive success since virginity cannot be selected for, but strong preference for virgin females could swamp or reinforce selection on other traits. Our results add to growing evidence that males are not indiscriminate in mating. However, given the unexplained heterogeneity in effect sizes, we urge caution in assuming that males will prefer virgins and recommend considering the natural context of mating decisions.
Collapse
Affiliation(s)
- Jon Richardson
- Department of Ecology, Evolution & Behavior, University of Minnesota, Saint Paul, Minnesota, USA
| | - Marlene Zuk
- Department of Ecology, Evolution & Behavior, University of Minnesota, Saint Paul, Minnesota, USA
| |
Collapse
|
2
|
House CM, Lewis Z, Sharma MD, Hodgson DJ, Hunt J, Wedell N, Hosken DJ. Sexual selection on the genital lobes of male Drosophila simulans. Evolution 2021; 75:501-514. [PMID: 33386741 DOI: 10.1111/evo.14158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/03/2020] [Accepted: 12/11/2020] [Indexed: 12/01/2022]
Abstract
Sexual selection is thought to be responsible for the rapid divergent evolution of male genitalia with several studies detecting multivariate sexual selection on genital form. However, in most cases, selection is only estimated during a single episode of selection, which provides an incomplete view of net selection on genital traits. Here, we estimate the strength and form of multivariate selection on the genitalia arch of Drosophila simulans when mating occurs in the absence of a competitor and during sperm competition, in both sperm defence and offense roles (i.e., when mating first and last). We found that the strength of sexual selection on the genital arch was strongest during noncompetitive mating and weakest during sperm offense. However, the direction of selection was similar across selection episodes with no evidence for antagonistic selection. Overall, selection was not particularly strong despite genitals clearly evolving rapidly in this species.
Collapse
Affiliation(s)
- Clarissa M House
- School of Science, Western Sydney University, Richmond, NSW, Australia
| | - Zenobia Lewis
- School of Life Sciences, University of Liverpool, Liverpool, UK
| | - Manmohan D Sharma
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hodgson
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - John Hunt
- School of Science, Western Sydney University, Richmond, NSW, Australia.,Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - Nina Wedell
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| | - David J Hosken
- Centre for Ecology and Conservation, College of Life & Environmental Sciences, University of Exeter, Cornwall, UK
| |
Collapse
|
3
|
House C, Tunstall P, Rapkin J, Bale MJ, Gage M, Del Castillo E, Hunt J. Multivariate stabilizing sexual selection and the evolution of male and female genital morphology in the red flour beetle. Evolution 2020; 74:883-896. [PMID: 31889313 PMCID: PMC7317928 DOI: 10.1111/evo.13912] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/11/2019] [Accepted: 12/15/2019] [Indexed: 11/28/2022]
Abstract
Male genitals are highly divergent in animals with internal fertilization. Most studies attempting to explain this diversity have focused on testing the major hypotheses of genital evolution (the lock‐and‐key, pleiotropy, and sexual selection hypotheses), and quantifying the form of selection targeting male genitals has played an important role in this endeavor. However, we currently know far less about selection targeting female genitals or how male and female genitals interact during mating. Here, we use formal selection analysis to show that genital size and shape is subject to strong multivariate stabilizing sexual selection in both sexes of the red flour beetle, Tribolium castaneum. Moreover, we show significant sexual selection on the covariance between the sexes for specific aspects of genital shape suggesting that male and female genitalia also interact to determine the successful transfer of a spermatophore during mating. Our work therefore highlights the important role that both male and female genital morphologies play in determining mating success and that these effects can occur independently, as well as through their interaction. Moreover, it cautions against the overly simplistic view that the sexual selection targeting genital morphology will always be directional in form and restricted primarily to males.
Collapse
Affiliation(s)
- Clarissa House
- School of Science and Health and Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia
| | - Philip Tunstall
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - James Rapkin
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - Mathilda J Bale
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| | - Matthew Gage
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Enrique Del Castillo
- Department of Industrial Engineering and Department of Statistics, Pennsylvania State University, State College, Pennsylvania, 16802
| | - John Hunt
- School of Science and Health and Hawkesbury Institute for the Environment, Western Sydney University, Richmond, NSW, 2753, Australia.,Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, TR10 9EZ, United Kingdom
| |
Collapse
|
4
|
House CM, Sharma MD, Okada K, Hosken DJ. Pre and Post-copulatory Selection Favor Similar Genital Phenotypes in the Male Broad Horned Beetle. Integr Comp Biol 2016; 56:682-93. [PMID: 27371390 PMCID: PMC5035384 DOI: 10.1093/icb/icw079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sexual selection can operate before and after copulation and the same or different trait(s) can be targeted during these episodes of selection. The direction and form of sexual selection imposed on characters prior to mating has been relatively well described, but the same is not true after copulation. In general, when male–male competition and female choice favor the same traits then there is the expectation of reinforcing selection on male sexual traits that improve competitiveness before and after copulation. However, when male–male competition overrides pre-copulatory choice then the opposite could be true. With respect to studies of selection on genitalia there is good evidence that male genital morphology influences mating and fertilization success. However, whether genital morphology affects reproductive success in more than one context (i.e., mating versus fertilization success) is largely unknown. Here we use multivariate analysis to estimate linear and nonlinear selection on male body size and genital morphology in the flour beetle Gnatocerus cornutus, simulated in a non-competitive (i.e., monogamous) setting. This analysis estimates the form of selection on multiple traits and typically, linear (directional) selection is easiest to detect, while nonlinear selection is more complex and can be stabilizing, disruptive, or correlational. We find that mating generates stabilizing selection on male body size and genitalia, and fertilization causes a blend of directional and stabilizing selection. Differences in the form of selection across these bouts of selection result from a significant alteration of nonlinear selection on body size and a marginally significant difference in nonlinear selection on a component of genital shape. This suggests that both bouts of selection favor similar genital phenotypes, whereas the strong stabilizing selection imposed on male body size during mate acquisition is weak during fertilization.
Collapse
Affiliation(s)
- Clarissa M House
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
| | - M D Sharma
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
| | - Kensuke Okada
- Laboratory of Evolutionary Ecology, Graduate School of Environmental Science, Okayama University, Tsushima-naka 1-1-1, Okayama, Japan
| | - David J Hosken
- *Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, TR10 9EZ, UK
| |
Collapse
|
5
|
Bath E, Tatarnic N, Bonduriansky R. Asymmetric reproductive isolation and interference in neriid flies: the roles of genital morphology and behaviour. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.08.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
6
|
|