Abstract
Evolutionary biologists commonly seek explanations for how selection drives the emergence of novel traits. Although trait loss is also predicted to occur frequently, few contemporary examples exist. In Hawaii, the Pacific field cricket (Teleogryllus oceanicus) is undergoing adaptive sexual signal loss due to natural selection imposed by eavesdropping parasitoids. Mutant male crickets (“flatwings”) cannot sing. We measured the intensity of sexual selection on wing phenotype in a wild population. First, we surveyed the relative abundance of flatwings and “normal-wings” (nonmutants) on Oahu. Then, we bred wild-mated females’ offspring to determine both female genotype with respect to the flatwing mutation and the proportion of flatwing males that sired their offspring. We found evidence of strong sexual selection favoring the production of song: females were predominantly homozygous normal-wing, their offspring were sired disproportionately by singing males, and at the population level, flatwing males became less common following a single sexual selection event. We report a selection coefficient describing the total (pre- and postcopulatory) sexual selection favoring normal-wing males in nature. Given the maintenance of the flatwing phenotype in Hawaii in recent years, this substantial sexual selection additionally suggests an approximate strength of opposing natural selection that favors silent males.
Original language | English (US) |
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Pages (from-to) | 1482-1489 |
Number of pages | 8 |
Journal | Evolution |
Volume | 73 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2019 |
Bibliographical note
Funding Information:JCT and ES collected the data. JCT analyzed the data and wrote the manuscript. All authors contributed to the design of the study and edited the manuscript. We thank John T. Rotenberry for his assistance with sampling crickets in the field; Nathan Indresano and Patrick O'Hare for cricket care; and Mounica Kota, Susan Balenger, and Justa Heinen-Kay for logistical support. Funding for this project was provided by a Theodore J. Cohn Research Grant from the Orthopterists? Society to ES and by the University of Minnesota Department of Ecology, Evolution, and Behavior. JCT was supported by an NSF Graduate Research Fellowship under grant number 00039202 and a Ford Foundation Pre-Doctoral Fellowship. MZ is supported by the National Science Foundation (US).
Funding Information:
We thank John T. Rotenberry for his assistance with sampling crickets in the field; Nathan Indresano and Patrick O’Hare for cricket care; and Mounica Kota, Susan Balenger, and Justa Heinen-Kay for logistical support. Funding for this project was provided by a Theodore J. Cohn Research Grant from the Orthopterists’ Society to ES and by the University of Minnesota Department of Ecology, Evolution, and Behavior. JCT was supported by an NSF Graduate Research Fellowship under grant number 00039202 and a Ford Foundation Pre-Doctoral Fellowship. MZ is supported by the National Science Foundation (US).
Publisher Copyright:
© 2019 The Author(s). Evolution © 2019 The Society for the Study of Evolution.
Keywords
- Acoustic communication
- eavesdropping
- rapid evolution
- selection coefficient
- sexual selection
- trait loss