Genomic architecture of adaptive radiation and hybridization in Alpine whitefish

In this genomic study on Alpine whitefish radiations, the authors reveal details on the genetic architecture underlying the repeated eco-morphological diversification and the role of hybridization in the evolution of endemic whitefish species. Adaptive radiations represent some of the most remarkable explosions of diversification across the tree of life. However, the constraints to rapid diversification and how they are sometimes overcome, particularly the relative roles of genetic architecture and hybridization, remain unclear. Here, we address these questions in the Alpine whitefish radiation, using a whole-genome dataset that includes multiple individuals of each of the 22 species belonging to six ecologically distinct ecomorph classes across several lake-systems. We reveal that repeated ecological and morphological diversification along a common environmental axis is associated with both genome-wide allele frequency shifts and a specific, larger effect, locus, associated with the gene edar. Additionally, we highlight the possible role of introgression between species from different lake-systems in facilitating the evolution and persistence of species with unique trait combinations and ecology. These results highlight the importance of both genome architecture and secondary contact with hybridization in fuelling adaptive radiation.

Automated summary

This study on genomic research of Alpine whitefish radiations reveals the role of genetic architecture and hybridization in diversification and evolution. The results show that ecological and morphological diversification is associated with genome-wide allele frequency shifts and a specific gene edar, while highlighting the importance of introgression between species from different lake-systems in the evolution and persistence of unique traits and ecology.