Speciation by sexual selection: 20 years of progress

Area of Science:

• Evolutionary Biology
• Speciation Research
• Sexual Selection Studies

Background:

• A foundational 20-year-old paper linked sexual selection to speciation via coordinated signal-preference evolution causing reproductive isolation.
• Recent research necessitates an updated perspective on the role of sexual selection in the speciation process.

Purpose of the Study:

• To review advancements in understanding sexual selection's role in speciation.
• To integrate new findings on mechanisms, the necessity of ecological divergence, and contextual influences on sexual selection's contribution to speciation.

Main Methods:

• Literature review and synthesis of recent empirical data and theoretical advancements.
• Analysis of mechanisms beyond female mate choice.
• Examination of conditions under which sexual selection drives reproductive isolation.

Main Results:

• Multiple mechanisms of sexual selection, beyond female choice, are now recognized as drivers of species origin and maintenance.
• Sexual selection typically requires ecological divergence to cause reproductive isolation, though exceptions exist.
• The contribution of sexual selection to divergence is context-dependent, varying with spatial, temporal, social, ecological, and genomic factors.

Conclusions:

• The role of sexual selection in speciation is more complex than previously understood, involving diverse mechanisms and contextual factors.
• Ecological divergence is often a prerequisite for sexual selection to lead to reproductive isolation.
• Future research should consider the multifaceted nature of sexual selection within specific speciation contexts.