Scientists watched a species evolve in real time, beak by beak

On a tiny Galapagos island, Peter and Rosemary Grant spent decades measuring every finch by hand, tracking how a single severe drought reshaped the population's average beak size within just a few generations. Natural selection wasn't an abstraction here — it was visible and measurable, and it even partly reversed once the rains returned. It remains one of the most direct demonstrations of evolution ever recorded in the wild.

— Jonathan Weiner, The Beak of the Finch — Pulitzer Prize-winning account (1994)
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