Which islands inspired Darwin's theory of evolution?

The Galápagos Islands, in the Pacific Ocean about 1,000 km off the coast of Ecuador, famously inspired Charles Darwin’s thinking about evolution. Darwin spent about five weeks there in 1835 during the voyage of HMS Beagle.

Islands That Inspired Darwin's Theory of Evolution

What Darwin noticed

Animal	Observation
Mockingbirds	Different species on different islands; these struck Darwin first
Finches	Beaks shaped for different foods, from seeds to insects
Giant tortoises	Locals could tell which island a tortoise came from by its shell; see the largest tortoise

Back in England, ornithologist John Gould told Darwin the finches were all separate species. Darwin realized they likely shared a common ancestor and had adapted to different islands. He published his theory in 1859; see what evolution is and what ship Darwin sailed on.

Wildlife found nowhere else

Marine iguanas, the only lizards that feed in the sea
Galápagos penguins, the only penguins living at the equator
Flightless cormorants
Blue-footed boobies, famous for their mating dance
Galápagos sea lions and giant tortoises

Many animals show little fear of people because they evolved without land predators.

Evolution still happening

Biologists Peter and Rosemary Grant studied finches on the tiny island of Daphne Major for decades. They measured beak sizes changing after droughts within just a few generations, direct evidence of natural selection.

Volcanic islands

The islands were formed by volcanoes above a hotspot, and some are still active. They have never been connected to the mainland, so animals arrived by swimming, flying or floating on rafts of vegetation.

Protecting the islands

About 97% of the land is a national park, created in 1959. Visitors must travel with licensed guides, and strict rules control tourism. Introduced goats, rats and plants are among the biggest threats. Darwin’s co-discoverer of natural selection worked in Asia; see who was Alfred Russel Wallace.