The Voyage of the Beagle · Chapter
Keeling Island: Coral Formations explained
Darwin describes the Keeling (Cocos) Islands, a coral atoll in the Indian Ocean.
What happens
Darwin describes the Keeling (Cocos) Islands, a coral atoll in the Indian Ocean. He details the settlement's history involving Malay slaves, the island's scanty flora and fauna, and the dominant role of the coconut tree. The chapter focuses extensively on coral reef formation, presenting his theory of atoll formation through subsidence, and contrasts fringing reefs, barrier reefs, and atolls.
Themes in this chapter
Natural Selection and Adaptation
Darwin observes the scanty flora and fauna, the transport of seeds by sea currents, and the adaptation of species like the land-crab and wading birds to isolated island conditions.
Human Impact on Environment
The introduction of rats from a wrecked ship and the settlement's reliance on the coconut tree highlight human influence on the island's ecology.
Geological Uniformitarianism
Darwin's theory of coral reef formation through slow subsidence and upward coral growth exemplifies uniformitarian processes over vast timescales.
Characters to notice
- Mr. Liesk
An English resident who came off in his boat when the Beagle arrived at Keeling Island.
- Captain Ross
Arrived from England with his family and goods to settle on the island; previously visited in his merchant-ship.
- Captain Fitz Roy
Accompanied Darwin to the settlement on Sunday, April 3rd.
- Mr. Waterhouse
Identified the rats on the islets as identical to the English kind, though smaller and more brightly colored.
- Chamisso
Described the natural history of a lagoon-island in the Radack Archipelago, noting similarities to Keeling Island.
Key passages
“The ring-formed reef of the lagoon-island is surmounted in the greater part of its length by linear islets. On the northern or leeward side, there is an opening through which vessels can pass to the anchorage within.”
The atoll's circular reef is mostly topped with narrow islands, and a passage on the sheltered north side allows ships to enter the lagoon.
Describes the physical structure of the atoll and its navigable entrance.
“We can now perceive how it comes that atolls, having sprung from encircling barrier-reefs, resemble them in general size, form, in the manner in which they are grouped together, and in their arrangement in single or double lines; for they may be called rude outline charts of the sunken islands over which they stand.”
Atolls originate from barrier reefs that once surrounded islands; as the islands sink, the reefs continue growing upward, leaving atolls as rough maps of the submerged land.
Summarizes Darwin's subsidence theory of atoll formation.