Evidence for stronger sexual selection in males than in females using an adapted method of Bateman's classic study of Drosophila melanogaster

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Natasha Davies - , University of Sussex (Author)
  • Tim Janicke - , TUD Dresden University of Technology, University of Montpellier (Author)
  • Edward H. Morrow - , University of Sussex, Karlstad University (Author)

Abstract

Bateman's principles, originally a test of Darwin's theoretical ideas, have since become fundamental to sexual selection theory and vital to contextualizing the role of anisogamy in sex differences of precopulatory sexual selection. Despite this, Bateman's principles have received substantial criticism, and researchers have highlighted both statistical and methodological errors, suggesting that Bateman's original experiment contains too much sampling bias for there to be any evidence of sexual selection. This study uses Bateman's original method as a template, accounting for two fundamental flaws in his original experiments, (a) viability effects and (b) a lack of mating behavior observation. Experimental populations of Drosophila melanogaster consisted of wild-type focal individuals and nonfocal individuals established by backcrossing the brown eye (bw-) eye-color marker - thereby avoiding viability effects. Mating assays included direct observation of mating behavior and total number of offspring, to obtain measures of mating success, reproductive success, and standardized variance measures based on Bateman's principles. The results provide observational support for Bateman's principles, particularly that (a) males had significantly more variation in number of mates compared with females and (b) males had significantly more individual variation in total number of offspring. We also find a significantly steeper Bateman gradient for males compared to females, suggesting that sexual selection is operating more intensely in males. However, female remating was limited, providing the opportunity for future study to further explore female reproductive success in correlation with higher levels of remating.

Details

Original languageEnglish
Pages (from-to)2420-2430
Number of pages11
JournalEvolution
Volume77
Issue number11
Publication statusPublished - Nov 2023
Peer-reviewedYes

Keywords

Keywords

  • Bateman's principles, Drosophila melanogaster, mating, reproductive success, sexual selection