The relationship between the termites and the cultivated fungus represents an impressive example of mutualistic symbiosis. The termites use chewed plant material, such as wood and dry grass, to feed the fungus and allow it to flourish, while the fungus converts otherwise indigestible plant material into nutrients the termites can utilize. Earlier work had shown that in the evolutionary past, a single, unreversed, transition to agriculture occurred in which termites domesticated a single lineage of fungi, represented today by the genus Termitomyces, a white rot fungus. These fungi are some of the few organisms that can digest the plant component lignin. Within the termite colonies, which can grow very large, the fungus grows on a special structure called the comb, which is maintained by the termites by the continual addition of new plant material.
Researchers Duur Aanen (University of Copenhagen) and Paul Eggleton (The Natural History Museum London), having sampled 58 colonies of fungus-cultivating termites (representing 49 species) in Senegal, Cameroon, Gabon, Kenya, South Africa, Madagascar, India, Sri Lanka, Thailand and Malaysian Borneo, now provide strong evidence that termite agriculture originated in African rain forest. Their reconstruction of ancestral habitats is based on the habitat of living species and analysis of DNA-based reconstructions of termite relationships.<