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Published on: August 22, 2013
Sexual selection and the differential effect of polyandry
Julie Collet1, David S Richardson, Kirsty Worley
1Department of Zoology, Edward Grey Institute, University of Oxford, Oxford OX1 3PS, United Kingdom.
Summary
Female promiscuity, known as polyandry, impacts male sexual selection. This study in red junglefowl reveals polyandry weakens overall sexual selection but strengthens postcopulatory selection, altering male mating dynamics.
Area of Science:
- Evolutionary Biology
- Behavioral Ecology
- Animal Reproduction
Background:
- Polyandry, or female promiscuity, presents opportunities for male sexual selection.
- Understanding how polyandry influences pre- and postcopulatory sexual selection is crucial but challenging.
- Previous research requires comprehensive mating and paternity data for accurate analysis.
Purpose of the Study:
- To investigate the effects of polyandry on pre- and postcopulatory sexual selection in red junglefowl (Gallus gallus).
- To determine how variation in mating behavior under polyandry influences male mating success and sexual selection intensity.
- To explore the role of male social status in sexual selection within different levels of polyandry.
Main Methods:
- Utilizing replicate seminatural groups of red junglefowl to observe mating behaviors.
- Collecting extensive data on mating patterns and paternity across the male population.
- Analyzing the variance in male mating success and its relationship with polyandry levels.
Main Results:
- Polyandry reduced variance in male mating success, thereby weakening overall sexual selection intensity.
- Conversely, polyandry increased the relative strength of postcopulatory sexual selection.
- In low-polyandry groups, male social status was strongly selected pre-copulation; in high-polyandry groups, selection for status shifted to post-copulation.
Conclusions:
- Polyandry acts as a significant modulator of sexual selection, dynamically altering its pre- and postcopulatory components.
- The findings highlight the complex interplay between mating systems and the intensity and nature of sexual selection.
- Male social status's role in sexual selection is significantly influenced by the degree of polyandry within a population.
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