Darwin's finches

'Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that [...] one species had been taken and modified for different ends.'
Charles Darwin

Some of the most famous birds of all time, Darwin's finches from the Galápagos Islands are the perfect model of evolution in action. The 13 species all look roughly the same - brown or black and sparrow-sized - but their beaks are considerably different, being brilliantly adapted to what they eat.

For example, those feeding on hard-to-crack seeds have big, strong beaks, while those targeting tiny insects have smaller, pointed beaks.

Darwin collected the birds during his five-year voyage on HMS Beagle. His journey inspired him to question how the diversity of life came to be, leading many years later to his book On the Origin of Species.

Yet at first he did not see the significance of these birds, thinking they were a mix of wrens, blackbirds, finches and warblers. It was only when John Gould, the famous English ornithologist, identified all the birds as finches that the pieces came together.

Darwin realised that the birds were related not just to one another, but also to the finches on the South American mainland. He suggested that, rather than being created as they were, they likely descended from common ancestors that had flown to the Galápagos Islands and adapted to their new environment.

Find out more about the birds collected aboard the HMS Beagle >
Explore other key objects related to the theory of evolution >