A beak size locus in Darwin's finches facilitated character displacement during a drought

Abstract

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 Galapagos 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.

Published in

Science
2016, volume: 352, number: 6284, pages: 470-474

SLU Authors

• Andersson, Leif

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    
  • Texas A&M University
  • Uppsala University

UKÄ Subject classification

Genetics and Breeding in Agricultural Sciences

Publication identifier

• DOI: https://doi.org/10.1126/science.aad8786

Permanent link to this page (URI)

https://res.slu.se/id/publ/80227