Sensory trade-offs predict signal divergence in Surfperch

Area of Science:

• Evolutionary biology
• Animal behavior
• Sensory ecology

Background:

• Receiver bias models predict unidirectional male trait evolution in sexual selection.
• Empirical tests have explored these models across various taxa.
• This study investigates an alternative, bidirectional pattern of trait evolution.

Purpose of the Study:

• To identify and explain the bidirectional pattern of male trait evolution.
• To test the sensory drive model by examining sensory constraints and signal evolution.
• To quantify the coevolution of communication traits driven by sensory trade-offs.

Main Methods:

• Combined species-specific measurements and ancestral estimates.
• Utilized visual detection modeling to analyze sensory biases.
• Examined visual pigments and male signal reflectance in five fish species.

Main Results:

• Sensory systems with detection trade-offs generate bidirectional biases.
• Species-specific visual pigments correlate with environmental changes, creating divergent sensory biases (luminance vs. chromatic detection).
• Male signal divergence aligns with predicted sensory biases, favoring either chromatic or luminance detection.

Conclusions:

• Sensory trade-offs in visual detection drive bidirectional signal evolution.
• Environmental factors shape sensory biases, leading to coevolution of communication traits.
• This study provides a quantitative example of sensory drive shaping signal evolution in a bidirectional manner.