Darwin's Finches: Evolution Visible in the Galápagos
The 18 species of Darwin's finches in the Galápagos — each with a beak adapted to a different food source — are the most famous example of adaptive radiation in nature; Puerto Ayora's gardens and the island's forests display all the species clearly
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Adaptive Radiation
The 18 Darwin's fin maps all descended from a single ancestral species that colonized the Galápagos 2-3 million years ago; the diversification of beak size and shape in response to different food sources (seeds, insects, cactus, blood) is the clearest example of natural selection in the world
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Medium Ground Finch
The medium-sized ground finch - the most common species, found everywhere in Puerto Ayora - has a medium-sized beak for cracking seeds; it was this species, combined with the cactus finch, that Darwin observed most closely; the beak variation within the species is the textbook example of natural selection
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Woodpecker
The woodpecker – which uses a cactus spine as a tool to extract insects from bark – is one of the few documented tool-using birds; The Galápagos finch's tool use, discovered in the 1960s, challenged the assumption that tool use was uniquely human
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Vampire Finch
The Wolf Island vampire finch - which pecks at the skin of its breasts to drink their blood when other food is scarce - is the most extreme example of dietary flexibility in the finch family; the behavior, an extension of parasite removal, shows how new ecological strategies evolve incrementally
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Peter Grant's research
Princeton biologists Peter and Rosemary Grant spent 40 years studying Darwin's finches on Daphne Major Island - measuring beak sizes after years of drought showed natural selection in real time; their research is the definitive proof that evolution occurs on observable time scales
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Finch observation in Puerto Ayora
Puerto Ayora Gardens, Darwin Station, and the Tortuga Bay Trail are all excellent for spotting multiple fin maps; the different species often feed side by side, making direct beak comparison possible; experience transforms the abstract concept of evolution into direct observation