Introgression catalyzing plumage evolution and speciation in an Asian songbird complex.

Introgression of melanin-related genes from T. ruficollis into Nau is linked to rapid plumage and genomic divergence in Asian thrushes.

• Why it matters: Understanding how gene flow influences speciation and phenotypic diversity addresses gaps in knowledge about mechanisms driving rapid divergence in closely related species.
• What they did: The study used a de novo chromosome-level genome and resequencing data from 66 individuals to analyze differentiation and introgression among Nau, Eun, and Ruf species.
• The result: Introgression of three melanin-related genes (ASIP, OCA2, HERC2) into Nau correlates with plumage similarity to Ruf, suggesting adaptive introgression as a driver of rapid divergence and speciation.