Substantially adaptive potential in polyploid cyprinid fishes: evidence from biogeographic, phylogenetic and genomic studies

Whole genome duplication is commonly believed to play key roles in vertebrate evolution. However, nowadays polyploidy exists in a few fish, amphibian, and reptile groups only, and seems to be an evolutionary dead-end in vertebrates. We investigate the evolutionary significance of polyploidization in Cyprinidae – a fish family that contains more polyploid species than any other vertebrate groups with integrating biogeographic, phylogenetic, and genomic analyses. First, polyploid species are found to be significantly frequent in higher altitude and lower mean annual temperature areas compared to diploid species in Cyprinidae. Second, a polyploidy-related diversification rate shift is observed in Cyprinidae. It is that increased net diversification rate is only seen in three polyploid lineages, and other polyploid lineages have similar net diversification rate as well as diploid lineages in Cyprinidae. Interestingly, significant ‘lag-times’ existed between polyploidization and radiation in...