The Galapagos Islands are formed of lava piles and dotted with s.... island galapago

The largest of the islands, , is approximately 82 miles (132 km) long and constitutes more than half of the total land area of the archipelago; it contains Mount Azul, at 5,541 feet (1,689 metres) the highest point of the Galapagos Islands. The climate of the Galapagos Islands is characterized by low rainfall, low humidity, and relatively low air and water temperatures. The close affinities of Galapagos animals to the fauna of South and Central America indicate that most of the islands' species originated there. A geologic study published in 1992 suggested that underwater seamounts near the Galapagos had formed islands between 5,000,000 and 9,000,000 years ago; this helped explain the great amount of endemic speciation, which many biologists believe could not have occurred in a lesser amount of time. The existing Galapagos Islands were formed between 700,000 and 5,000,000 years ago, making them geologically young. The islands' human inhabitants, mostly Ecuadorans, live in se! ttlements on , Santa Mar Isabela, and Santa Cruz islands; has an Ecuadoran military base. Steadman and Steven Zousmer, Gal gos: Discovery on Darwin's Islands (1988); and Isabel Castro and Antonia Phillips, A Guide to the Birds of the Gal gos Islands (1996). James (ed.), Gal gos Marine Invertebrates: Taxonomy, Biogeography, and Evolution in Darwin's Islands (1991); Paul Humann, Reef Fish Identification: Gal gos, ed. Lavenberg, The Fishes of the Gal gos Islands (1997). Guidebooks include Barry Boyce, A Traveler's Guide to the Galapagos Islands, 2nd ed. island galapago