Sexual selection drives asymmetric introgression in wall lizards

Area of Science:

• Evolutionary biology
• Genetics
• Herpetology

Background:

• Hybridization is a significant evolutionary mechanism driving diversification and adaptation.
• Divergence in male secondary sexual characters between lineages can lead to asymmetric reproductive success.

Discussion:

• Asymmetric hybridization occurs when one lineage dominates mating due to superior male competitive ability.
• No negative effects on F1-hybrid survival or reproduction facilitate asymmetric introgression.
• Sexual selection on male traits can dictate the direction and extent of genetic introgression.

Key Insights:

• Male competitive ability and mating success asymmetries drive unidirectional introgression in Podarcis muralis lizards.
• Sexual character divergence dictates the pattern of genetic and phenotypic diversity in contact zones.
• The sub-dominant lineage's sexual characters are displaced due to asymmetric hybridization.

Outlook:

• Understanding trait-driven introgression is crucial for predicting evolutionary trajectories and biodiversity patterns.
• Further research can explore the genetic basis of divergent sexual characters and their impact on hybridization.
• This model can be applied to other species experiencing secondary contact and hybridization.