Key facts

• The wildlife and the theory of natural selection: the tameness of Galápagos wildlife is as important as its diversity — the animals of the Galápagos evolved in the absence of mammalian predators; land iguanas, marine iguanas, tortoises, sea lions, and most bird species show no fear of humans — a masked booby will sit on its nest while you photograph it from 50 cm; a sea lion will swim with you in the shallows; a marine iguana will stare at you while you lie on the rocks beside it; Charles Darwin arrived on HMS Beagle on 15 September 1835 and spent 5 weeks collecting specimens; his observations of the Galápagos finches (13 species on different islands, each with a beak shape uniquely adapted to the food sources available on that island; the finches all share a common ancestor that arrived from South America; their diversification into different food niches across the islands is one of the clearest demonstrations of adaptive radiation) were central to his formulation of the theory of natural selection in On the Origin of Species (1859); the Galápagos mockingbirds (4 species, each endemic to a different set of islands) were actually more significant for Darwin’s thinking than the finches, though the finches became the iconic symbol of evolution
• The marine iguana (Amblyrhynchus cristatus): the only seagoing lizard on Earth and the most bizarre reptile in the Galápagos — the marine iguana (endemic to the Galápagos; largest males up to 1.4 kg; the only lizard that feeds in the sea; they dive to 10 metres and graze on marine algae on underwater rocks; they can remain submerged for up to 30 minutes; they lose heat rapidly while diving in the cold Humboldt Current water and need to bask in the sun for several hours after feeding to restore body temperature; while basking, they expel excess salt from glands in their nostrils — a visible stream of white crystalline salt secreted from the nostril is the characteristic behaviour of a basking marine iguana; the iguanas are colonial — beaches and rocky areas may host hundreds of individuals stacked on top of each other in basking piles; they run no faster than walking pace and will not move away from you unless you step over them)
• The Galápagos giant tortoise: the largest living tortoise and the iconic symbol of the islands — the Galápagos giant tortoise (Chelonoidis niger; different species or subspecies exist on different islands; the total population was reduced to approximately 3,000 individuals by the early 20th century due to hunting by whalers and pirates who used them as a live food source — giant tortoises can survive without food or water for months and were stored upside-down in ships’ holds; the total population has recovered to approximately 10,000–15,000 individuals; the most famous individual was Lonesome George, the last Pinta Island tortoise, who died on 24 June 2012 at approximately 100 years of age; a captive breeding programme at the Charles Darwin Research Station on Santa Cruz has been breeding tortoise species from various islands and releasing the hatchlings into the wild since the 1970s; the saddle-back shell shape (found on islands where vegetation is sparse and ground-level; the long neck and raised shell front allow the tortoise to reach overhead cactus pads) vs. the domed shell shape (found on islands with abundant low vegetation; the dome shell and shorter neck are adapted to grazing low) are a famous example of adaptation within a single genus)
• Heritage: UNESCO World Heritage Site (Galápagos Islands), inscribed 1978 (inaugural list)
• GPS: -0.6667° S, -90.5500° W