Sexual selection and 'species recognition' revisited: serial processing and order-of-operations in mate choice

Area of Science:

• Evolutionary biology
• Animal behavior
• Bioacoustics

Background:

• Mating signals were initially viewed as species recognition traits, later expanded to include sexual selection and mate choice.
• The dual function of signals (recognition vs. quality) was proposed to stem from female preference functions but lacked empirical testing.
• Contrasting properties of recognition (stereotyped, low variation) and quality (condition-dependent, high variation) signals pose a challenge.

Purpose of the Study:

• To test the hypothesis that different mating signal components are evaluated sequentially: first for recognition, then for quality.
• To investigate the relationship between signal variation, female preference, and phylogenetic signal in cricket calls.

Main Methods:

• Analysis of intraspecific variation in male cricket call components.
• Characterization of female preference function shapes for these components.
• Assessment of phylogenetic signal across different call components.

Main Results:

• Early-processed signal components exhibit low intraspecific variation, closed female preference functions, and low phylogenetic signal.
• Later-processed signal components show high intraspecific variation, open preference functions, and high phylogenetic signal.
• These patterns support a sequential 'order-of-operations' in mating signal evaluation.

Conclusions:

• Mating signal processing follows a distinct sequence, prioritizing species recognition before mate quality assessment.
• This 'order-of-operations' model provides a framework for understanding signal evolution across diverse taxa and sensory modalities.