Strongly selected characters can be transferred from one lineage to another with limited genetic exchange, resulting in asymmetric introgression and a mosaic genome in the receiving population. However, systems are rarely sufficiently well studied to link the pattern of introgression to its underlying process. Male common wall lizards in western Italy exhibit exaggeration of a suite of sexually selected characters that make th...

Many populations are small and isolated with limited genetic variation and high risk of mating with close relatives. Inbreeding depression is suspected to contribute to extinction of wild populations, but the historical and demographic factors that contribute to reduced population viability are often difficult to tease apart. Replicated introduction events in non‐native species can offer insights into this problem because they...

Hybridisation is increasingly recognised as an important cause of diversification and adaptation. Here, we show how divergence in male secondary sexual characters between two lineages of the common wall lizard ( Podarcis muralis ) gives rise to strong asymmetries in male competitive ability and mating success, resulting in asymmetric hybridisation upon secondary contact. Combined with no negative effects of hybridisation on su...