Spatial variation in gene flow across a hybrid zone reveals causes of reproductive isolation and asymmetric introgression in wall lizards

Weizhao Yang, Nathalie Feiner, Hanna Laakkonen, Roberto Sacchi, Marco Zuffi, Stefano Scali, Geoffrey M. While, Tobias Uller

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Hybrid zones provide insights into the evolution of reproductive isolation. Sexual selection can contribute to the evolution of reproductive barriers, but it remains poorly understood how sexual traits impact gene flow in secondary contact. Here, we show that a recently evolved suite of sexual traits that function in male-male competition mediates gene flow between two lineages of wall lizards (Podarcis muralis). Gene flow was relatively low and asymmetric in the presence of exaggerated male morphology and coloration compared to when the lineages share the ancestral phenotype. Putative barrier loci were enriched in genomic regions that were highly differentiated between the two lineages and showed low concordance between the transects. The exception was a consistently low genetic exchange around ATXN1, a gene that modulates social behavior. We suggest that this gene may contribute to the male mate preferences that are known to cause lineage-assortative mating in this species. Although female choice modulates the degree of reproductive isolation in a variety of taxa, wall lizards demonstrate that both male-male competition and male mate choice can contribute to the extent of gene flow between lineages.

Original languageEnglish
JournalEvolution
Volume74
Issue number7
Pages (from-to)1289-1300
Number of pages12
ISSN0014-3820
DOIs
Publication statusPublished - 24 May 2020
Externally publishedYes
MoE publication typeA1 Journal article-refereed

Fields of Science

  • CHEMICAL COMMUNICATION
  • DIVERGENCE
  • GENOME
  • HISTORY
  • INFERENCE
  • LOCI
  • POPULATION-STRUCTURE
  • Podarcis muralis
  • SECONDARY CONTACT
  • SEXUAL SELECTION
  • SPECIATION
  • barrier loci
  • genomic cline analysis
  • hybrid zone
  • introgression
  • sexual selection
  • 1181 Ecology, evolutionary biology

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