Schematic illustration of the evolution of the Big Bird lineage on the Daphne Major island in the Galápagos archipelago. Initially an immigrant large cactus finch male (Geospiza conirostris) bred with a medium ground finch female (Geospiza fortis). Their offspring bred with each other and established the Big Bird lineage.
Photos © K. Thalia Grant for G. conirostris and Peter R. Grant for the remainder. Reproduced with permission from K. Thalia Grant, and Princeton University Press, which first published the remaining images in 40 Years of Evolution (P. R. Grant & B. R. Grant, 2014).