Simulated evolution of mating signal diversification in a primate radiation

Area of Science:

• Evolutionary biology
• Speciation research
• Primate evolution

Background:

• Phenotypic diversity is often driven by divergence in allopatry and reinforcement of mating signals upon secondary contact.
• Observing these evolutionary processes directly is challenging, necessitating the use of simulations.
• Guenons, a primate radiation, display diverse face patterns hypothesized to maintain reproductive isolation through mate choice.

Purpose of the Study:

• To investigate the evolutionary drivers of phenotypic diversity in mating signals using simulations.
• To model the evolution of primate face patterns under varying scenarios of allopatry and sympatry.
• To identify key parameters influencing evolutionary outcomes in speciation.

Main Methods:

• Developed evolutionary simulations of mating signal evolution in phenotype space.
• Modeled mate recognition signals in guenons, focusing on face pattern evolution.
• Simulated periods of allopatry and sympatry to analyze evolutionary trajectories.

Main Results:

• Diversification in allopatry coupled with assortative mate choice during secondary contact rapidly drives phenotypic diversification.
• Distinctive (between-species) and stereotyped (within-species) face patterns emerge, mirroring extant guenons.
• Strong selection against hybrids is essential for diversification; low hybrid fitness leads to population merging.

Conclusions:

• Reinforcement by assortative mating plays a key role in maintaining species diversity.
• Simulation results support the hypothesis that this process explains the striking diversity in guenon face patterns.
• The study highlights the power of simulated evolution in understanding complex evolutionary phenomena.