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Published on: August 22, 2013
Postcopulatory sexual selection: Darwin's omission and its consequences
1Smithsonian Tropical Research Institute and Escuela de Biologia, Universidad de Costa Rica, San José, Costa Rica. william.eberhard@gmail.com
Summary
Darwin overlooked postcopulatory sexual selection, including sperm competition and cryptic female choice within females. This hidden competition drives diverse traits in sperm, genitalia, and reproductive behaviors.
Area of Science:
- Evolutionary Biology
- Reproductive Biology
- Sexual Selection
Background:
- Charles Darwin's theory of sexual selection primarily focused on pre-copulatory events.
- Male-male competition and female choice extend beyond copulation, occurring internally within the female reproductive tract.
Purpose of the Study:
- To highlight Darwin's oversight regarding postcopulatory sexual selection.
- To explore the implications of internal sexual competition on diverse biological phenomena.
Main Methods:
- Review of existing literature on sexual selection and reproductive strategies.
- Analysis of morphological and behavioral adaptations related to postcopulatory competition.
Main Results:
- Identified postcopulatory sexual selection mechanisms: sperm competition and cryptic female choice.
- Documented elaborate and paradoxical adaptations in male genitalia, sperm, and non-genitalic structures.
- Highlighted the influence of seminal products on female physiology and behavior.
- Observed post-copulatory courtship behaviors and complex interactions between gametes and reproductive tissues.
Conclusions:
- Postcopulatory sexual selection is a significant evolutionary force, shaping diverse reproductive traits.
- Understanding internal sexual competition offers new insights into the evolution of reproductive systems and behaviors across species.
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