Abstract
In the natural world, sex prevails, despite its costs. Although much effort has been dedicated to identifying the intrinsic costs of sex (e.g., the cost of males), few studies have identified the ecological fitness consequences of sex. Furthermore, correlated biological traits that differ between sexuals and asexuals may alter these costs, or even render the typical costs of sex irrelevant. We conducted a large-scale, multisite, reciprocal transplant using multiple sexual and asexual genotypes of a native North American wildflower to show that sexual genotypes have reduced lifetime fitness, despite lower herbivory. We separated the effects of sex from those of hybridity, finding that overwinter survival is elevated in asexuals regardless of hybridity, but herbivores target hybrid asexuals more than nonhybrid asexual or sexual genotypes. Survival is lowest in homozygous sexual lineages, implicating inbreeding depression as a cost of sex. Our results show that the consequences of sex are shaped not just by sex itself, but by complex natural environments, correlated traits, and the identity and availability of mates.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 516-529 |
| Number of pages | 14 |
| Journal | Evolution Letters |
| Volume | 4 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 2020 |
Bibliographical note
Funding Information:The authors wish to thank S. Clemens, R. Keith, C.‐R. Lee, M. McMunn, T. Park, K. Putney, E. Raskin, K. Stiff, C. Strock, M. Wagner, and A. Zemenick for their help with field work. We are especially grateful to R.‐M. (Diana) Mao for her work quantifying seed set and pollen viability. We also thank J. Mojica for his statistical expertise and R. Colautti for his help with both statistics and in the field, and J. Willis, M. Noor, M. Rausher, B. Koskella, and M. Windham for useful conversations. We are grateful for the constructive comments of two anonymous reviewers and Associate Editor S. Wright. This work was supported by funding from the National Science Foundation (Graduate Research Fellowship to CAR and DEB‐1311269 to CAR and TM‐O) and the National Institutes for Health (R01 GM086496 to TM‐O). The authors declare no conflicts of interest.
Publisher Copyright:
© 2020 The Authors. Evolution Letters published by Wiley Periodicals, LLC on behalf of Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEB).
Keywords
- Apomixis
- Boechera
- asexuality
- evolution of sex
- herbivory
- hybridization
- reciprocal transplant
- viability selection