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Sex differences, sexual selection, and ageing: an experimental evolution approach.
Alexei A Maklakov1, Russell Bonduriansky, Robert C Brooks
1Evolution & Ecology Research Centre and School of Biological, Earth and Environmental Sciences, The University of New South Wales, Kensington, Sydney 2052, Australia. Alexei.Maklakov@ebc.uu.se
Evolution; International Journal of Organic Evolution
|June 13, 2009
Summary
Life-history selection drives changes in reproduction and mortality, but sexual selection has minimal impact on these adaptive traits. Sex differences in life history, shaped by past sexual selection, are crucial for responding to new environmental challenges.
Area of Science:
- Evolutionary Biology
- Life-History Theory
- Sexual Selection
Background:
- Life-history theory posits a trade-off between reproduction and somatic maintenance, influencing aging and lifespan.
- Sexual selection and conflict impact reproductive strategies, potentially affecting lifespan and aging evolution.
- Previous research on sexual selection's role in aging evolution yielded equivocal results.
Purpose of the Study:
- To investigate if sexual selection influences the adaptive evolution of age-specific life-history traits.
- To examine the impact of sexual selection on the evolution of age at reproduction and associated traits.
Main Methods:
- A novel selection experiment was conducted on the seed beetle Callosobruchus maculatus.
- Populations were selected for early or late reproduction, with and without sexual selection.
- Age-specific reproduction and mortality rates were measured to assess evolutionary changes.
Main Results:
- Life-history selection successfully evolved age-specific reproduction and mortality patterns.
- Sexual selection did not significantly alter these life-history adaptations.
- Sexual selection negatively impacted overall reproductive performance and adaptation.
- Sex differences in trait evolution were observed, suggesting historical influences of sexual selection.
Conclusions:
- Current sexual selection appears to have limited importance in promoting rapid adaptation to environmental changes.
- Sex differences in life-history traits, a legacy of past sexual selection, are vital for responding to novel selective pressures.
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