Darwin’s finches are the Galápagos birds that helped inspire Darwin’s ideas about evolution.
The name refers to a group of small passerine birds native to the Galápagos Islands and nearby Cocos Island. Their ancestors likely arrived from mainland South America, after which isolated island populations diverged. Differences in beak size and shape are associated with different diets and feeding strategies.
Darwin collected specimens during the voyage of HMS Beagle, but he did not immediately understand the evolutionary importance of every finch. Later comparisons helped him recognize that related island forms could have descended from a common ancestor. The birds became an especially clear example of adaptive radiation.
They are not all true finches in the strict taxonomic sense; they belong mainly to the tanager family Thraupidae. Modern research also shows that their evolution is dynamic, with hybridization and changing selection contributing to variation.