Community-wide genome sequencing reveals 30 years of Darwin’s finch evolution
Erik D. Enbody, Ashley T. Sendell‐Price, C. Grace Sprehn, Carl‐Johan Rubin, Peter M. Visscher, B. Rosemary Grant, Peter R. Grant, Leif Andersson
Abstract
A fundamental goal in evolutionary biology is to understand the genetic architecture of adaptive traits. Using whole-genome data of 3955 of Darwin’s finches on the Galápagos Island of Daphne Major, we identified six loci of large effect that explain 45% of the variation in the highly heritable beak size of Geospiza fortis, a key ecological trait. The major locus is a supergene comprising four genes. Abrupt changes in allele frequencies at the loci accompanied a strong change in beak size caused by natural selection during a drought. A gradual change in Geospiza scandens occurred across 30 years as a result of introgressive hybridization with G. fortis . This study shows how a few loci with large effect on a fitness-related trait contribute to the genetic potential for rapid adaptive radiation.