Can reinforcement occur with a learned trait?

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Genetics

Background:

• Reinforcement is a key evolutionary process driving speciation.
• Socially learned traits, like birdsong, pose unique challenges to reinforcement.
• Understanding the interplay between genetic predisposition and learned traits is crucial for evolutionary studies.

Purpose of the Study:

• To investigate if reinforcement can occur when female mating preference is genetically determined for a socially learned male trait.
• To model the conditions under which population-specific songs are maintained alongside mating preferences.

Main Methods:

• Using birdsong as a model system.
• Simulating secondary contact between populations with distinct song dialects.
• Analyzing the spread of mating preference alleles under varying genetic predispositions for song learning.

Main Results:

• Reinforcement based on song does not occur when genetic predispositions for song learning are weak and fixed within a population.
• When some individuals have strong predispositions, limiting song phenotype overlap, reinforcement is only slightly inhibited compared to purely genetic models.
• Socially learned signals generally inhibit reinforcement, but it can still happen if some individuals genetically acquire trait phenotypes.

Conclusions:

• Socially learned traits can impede reinforcement, potentially slowing speciation.
• Genetic predispositions play a critical role in enabling reinforcement for learned signals.
• Partial genetic determination of learned traits may allow reinforcement to occur, albeit with reduced efficiency.