Read at : Science Daily
http://www.sciencedaily.com/releases/2009/11/091120000437.htm
Termites Create Sustainable Monoculture Fungus Farming
ScienceDaily (Nov. 22, 2009) — Food production of modern human societies is mostly based on large-scale monoculture crops, but it now appears that advanced insect societies have the same practice. Our societies took just ten thousand years of (mainly cultural) evolution to adopt this habit and we are far from convinced that it is sustainable. Farming ants and termites had tens of millions of years to evolve their fungus farming systems and here monocultures are apparently evolutionary stable.
In a study published in the journal Science, researchers from the Laboratory of Genetics of Wageningen University and the Centre for Social Evolution at the University of Copenhagen take significant steps to resolve this puzzle.
The fungus-growing termites of the old-world tropics build impressive mounds consisting of thousands of workers and soldiers. These societies domesticated African Termitomyces mushrooms more than 30 million years ago and became obligatorily dependent on farming their own fungal food in their often gigantic nest mounds. The termite fungus-farming symbiosis had a single African rain-forest origin and now comprises ca 330 species. It is of major ecological importance for decomposition and mineralcycling.
A colony-founding termite queen and king normally do not acquire their first garden until they have raised the first workers. These helpers collect Termitomyces spores while foraging, together with the plant material that they defecate in the nest to establish a garden substrate. These spores are amply available because the fungus gardens produce large mushrooms once a year on top of the termite mounds.
However, this farming practice offers a paradox: Evolutionary theory predicts that symbioses with multiple lineages per colony should be unstable, because these genotypes can be expected to compete for making mushrooms rather than collaborate to serve the termite farmers.
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Adapted from materials provided by Wageningen University and Research Centre, via AlphaGalileo.
