A beak size locus in Darwin's finches facilitated character displacement during a drought.
Ecological character displacement is a process of morphological divergence that reduces competition for limited resources. We used genomic analysis to investigate the genetic basis of a documented character displacement event in Darwin's finches on Daphne Major in the Galápagos Islands: The medium ground finch diverged from its competitor, the large ground finch, during a severe drought. We discovered a genomic region containing the HMGA2 gene that varies systematically among Darwin's finch species with different beak sizes. Two haplotypes that diverged early in the radiation were involved in the character displacement event: Genotypes associated with large beak size were at a strong selective disadvantage in medium ground finches (selection coefficient s = 0.59). Thus, a major locus has apparently facilitated a rapid ecological diversification in the adaptive radiation of Darwin's finches.
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Sangeet
S
Lamichhaney
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Fan
F
Han
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Jonas
J
Berglund
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Chao
C
Wang
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Markus Sällman
MS
Almén
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
Matthew T
MT
Webster
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
B Rosemary
BR
Grant
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA.
Peter R
PR
Grant
Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden. Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden. Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA. leif.andersson@imbim.uu.se.
Leif
L
Andersson
D000818:Animals; D001502:Beak / Q000033:anatomy & histology*; D049628:Body Size / Q000235:genetics; D055864:Droughts; D004484:Ecuador; D005260:Female; D046369:Finches / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics*; D023281:Genomics; D005838:Genotype; D025743:HMGA2 Protein / Q000235:genetics; D006239:Haplotypes; D009929:Organ Size / Q000235:genetics; D010802:Phylogeny; D040641:Quantitative Trait Loci; D012641:Selection, Genetic
D025743:HMGA2 Protein