Peter & Rosemary Grant's Groundbreaking Galápagos Finch Research

Evolutionary biologists Peter and Rosemary Grant have studied Darwin's finches on the Galápagos Islands since the 1970s, providing real-time evidence of natural selection.

Key Findings

• Beak-size variation among finch species correlates with seed size: longer beaks crack large seeds; shorter beaks handle small seeds.
• Rapid evolutionary change observed in medium ground finches (Geospiza fortis) on Daphne Major after a severe 1977 drought. With small seeds scarce, larger-beaked birds survived and reproduced more, increasing average beak size and fitness within just a few years.

Their decades-long field work demonstrated evolution occurring on a contemporary, observable timescale.