A volcanic archipelago on the Equator, washed by nutrient-rich currents, where giant tortoises live on land and marine iguanas graze algae in the sea. Darwin visited in 1835, and the islands later influenced his evolutionary thinking.
The Galápagos comprise 127 islands, islets and rocks, including 19 large islands, about 1,000 km from Ecuador. Volcanism and converging currents shape an unusual ecosystem with high endemism.
Charles Darwin visited from 15 September to 20 October 1835; Darwin walked these islands in 1835, and the finches are still changing — the radiation did not end with the Beagle. Evolution here did not stop in 1835: long-running finch studies track selection as drought changes seeds, tree daisies carry a plant radiation, and introduced insects keep reshaping island communities.
About 97% of the land is protected as national park, and UNESCO inscribed the islands in 1978. Isolation among islands helped tortoise and finch populations diverge into different living stories.
A 2024 synthesis puts native-reptile endemism at about 72%. Marine iguanas can shrink in length during El Niño food crashes, then later regrow — a measured survival response.
The islands take their name from "galápago", an old Spanish word for a saddle — after the tortoises' curved shells.
A giant tortoise can go about a year without eating or drinking a drop.
The Galápagos formed over a volcanic hotspot.
The marine iguana dives and grazes algae underwater.
After a salty meal these iguanas sneeze out the extra salt, often leaving a white crust on their heads.
Galápagos penguins live and breed around equatorial islands, mainly in the cooler western archipelago.
Field Notes
Darwin's Five Weeks
HMS Beagle reached the Galápagos on 15 September 1835, and Charles Darwin explored until 20 October. About 97% of the land is now national park, and UNESCO inscribed the islands in 1978.
His notes from those weeks later fed his thinking about how isolated populations can change. Evolution here did not stop in 1835: long-running finch studies track selection as drought changes seeds, tree daisies carry a plant radiation, and introduced insects keep reshaping island communities.
Darwin walked these islands in 1835 — and the radiation is still a living process.
Research Report
Where Cold Meets the Equator
The islands sit on the Equator, yet converging currents bring cool, nutrient-rich water — three currents meet here. A marine lizard that dives to graze algae, then basks on lava.
During El Niño food crashes it can shrink in length and later regrow — a measured survival response, not a party trick. The same cool water supports blue-footed boobies and Galápagos penguins around the western archipelago.
The bluer the feet, the better the bird has been eating — females use that colour as a courtship cue.
Expert Dossier
One Family, Many Islands
Isolation among islands helped populations diverge. Giant tortoises of the Galápagos — different living species on different islands, each with its own story — form an island complex, not one badge for every volcano.
Shell shape and living species differ by island. Darwin's finches vary too, and the finches are still changing — the radiation did not end with the Beagle.
A 2024 synthesis puts native-reptile endemism at about 72%. That is why a single endangered label cannot stand for the whole tortoise family.