The coconut (the fruit of the palm Cocos nucifera) provides a high-calorie food, potable water, fibre that can be spun into rope, a hard shell that can be turned into charcoal - and until it is needed for some other purpose it serves as a handy flotation device.
     So extensively is the history of the coconut interwoven with the history of people travelling the oceans, that Kenneth Olsen - a plant evolutionary biologist - didn't expect to find much geographical structure to coconut genetics. He was in for a surprise. It turns out there are two different populations of coconuts, strongly suggesting the coconut was brought under cultivation in two separate locations - one in the Pacific and the other in the Indian Ocean. What's more, coconut genetics also preserve a record of prehistoric trade routes and of the colonisation of the Americas.
     One exception to the general Pacific/Indian Ocean split is the western Indian Ocean, where coconuts are a genetic mixture of the two types. Olsen adds that a recent study of rice varieties found in Madagascar shows a similar mixing of rice varieties from Southeast Asia and India. The Indian Ocean coconut was transported to the New World by Europeans - from the Indian Ocean to the west coast of Africa, into the Caribbean and also to coastal Brazil.
     On the Pacific side of the New World tropics, however, the coconuts are Pacific Ocean coconuts. Some appear to have been transported there in pre-Columbian times by ancient Austronesians. During the colonial period, the Spanish brought coconuts to the Pacific coast of Mexico from the Philippines.
     This is why, Olsen says, you find Pacific type coconuts on the Pacific coast of Central America and Indian type coconuts on the Atlantic coast.

Edited from Past Horizons (28 June 2011)