The definition of sexual selection

Area of Science:

• Evolutionary Biology
• Reproductive Biology
• Behavioral Ecology

Background:

• Sexual selection, a core evolutionary concept, has faced ongoing debate since Darwin.
• Recent discussions question the fundamental definition and scope of sexual selection.
• Incorporating female-female competition into sexual selection frameworks remains a challenge.

Purpose of the Study:

• To examine the requirements for a robust definition of sexual selection.
• To propose a precise definition of sexual selection.
• To explore the implications of this definition for understanding reproductive competition and resource competition.

Main Methods:

• Literature review and conceptual analysis.
• Examination of Darwin's original ideas and contemporary usage.
• Analysis of alternative definitions, including female competition.
• Testing the proposed definition against various evolutionary scenarios.

Main Results:

• A proposed definition: sexual selection is any selection arising from fitness differences due to nonrandom success in competition for access to gametes for fertilization.
• Distinction made between sexual selection (gamete access) and natural selection (resource access).
• Exploration of complex scenarios where natural and sexual selection may overlap or interact.

Conclusions:

• The proposed definition aligns with Darwin's foundational ideas and current biological understanding.
• While ecological realities are complex, a clear and simple definition of sexual selection is achievable.
• Clarifying the definition aids in understanding the nuances of reproductive competition and evolutionary processes.