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Research article - Peer-reviewed, 2021

A multispecies BCO2 beak color polymorphism in the Darwin's finch radiation

Enbody, Erik D.; Sprehn, C. Grace; Abzhanov, Arhat; Bi, Huijuan; Dobreva, Mariya P.; Osborne, Owen G.; Rubin, Carl-Johan; Grant, Peter R.; Grant, B. Rosemary; Andersson, Leif


Carotenoid-based polymorphisms are widespread in populations of birds, fish, and reptiles,(1) but generally little is known about the factors affecting their maintenance in populations.(2) We report a combined field and molecular-genetic investigation of a nestling beak color polymorphism in Darwin's finches. Beaks are pink or yellow, and yellow is recessive.(3) Here we show that the polymorphism arose in the Galapagos half a million years ago through a mutation associated with regulatory change in the BCO2 gene and is shared by 14 descendant species. The polymorphism is probably a balanced polymorphism, maintained by ecolog- ical selection associated with survival and diet. In cactus finches, the frequency of the yellow genotype is correlated with cactus fruit abundance and greater hatching success and may be altered by introgressive hybridization. Polymorphisms that are hidden as adults, as here, may be far more common than is currently recognized, and contribute to diversification in ways that are yet to be discovered.

Published in

Current Biology
2021, volume: 31, number: 24, pages: 5597-+
Publisher: CELL PRESS

Authors' information

Enbody, Erik D.
Uppsala University
Sprehn, C. Grace
Uppsala University
Abzhanov, Arhat
Imperial College London
Bi, Huijuan
Uppsala University
Dobreva, Mariya P.
Imperial College London
Osborne, Owen G.
Bangor University
Rubin, Carl-Johan
Uppsala University
Grant, Peter R.
Princeton University
Grant, B. Rosemary
Princeton University
Andersson, Leif
Uppsala University
Andersson, Leif
Swedish University of Agricultural Sciences, Department of Animal Breeding and Genetics
Andersson, Leif
Texas A&M University

UKÄ Subject classification

Evolutionary Biology

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