The evolution of hemoglobin function in the transition from water‐ to air‐breathing has been highly debated but remains unresolved. Here, we characterized the hemoglobin function in five closely related water‐ and air‐breathing catfishes. We identify distinct directions of hemoglobin evolution in the clades that evolved air‐breathing, and we show strong selection on hemoglobin function within the catfishes. These findings show that the lack of a general direction in hemoglobin function in the transition from water‐ to air‐breathing may have resulted from divergent selection on hemoglobin function in independent clades of air‐breathing fishes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.