Climate Shapes the Geographic Distribution and Introgressive Spread of Color Ornamentation in Common Wall Lizards

Climate can exert an effect on the strength of sexual selection, but empirical evidence is limited. Here, we tested whether climate predicts geographic distribution and introgressive spread sexually selected male color ornamentation across 114 populations common wall lizard, Podarcis muralis. Coloration was highly structured landscape did not reflect genetic differentiation. Instead, consistently exaggerated in hot dry environments, suggesting that climate-driven selection maintains variation spite gene flow. Introgression into a distantly related lineage appears to be ongoing particularly pronounced warm climates with wet winters summers. Combined, these results suggest favored allow prolonged reproductive season high reliable opportunities for lizard activity. This pattern corroborates theoretical predictions such climatic conditions reduce temporal clustering receptive females increase male-male competition, resulting strong selection. In summary, provide compelling importance evolution ornamentation, demonstrate influences introgression this phenotype.