Humans were far from the first creatures to invent either farming or gardening, and new research suggests that we may have been pipped to the pastoral post by termites around 31 million years ago. A study published this week in the journal PLOS One describes how an ancient species of the acid-shooting insects cultivated fungus gardens, farming the mouldy microorganisms as a key source of nutrition.
A similar practice has been noted in modern termites, some species of which have developed highly specialized symbiotic relationships with the fungi in their gardens. The way this works is that the fungi partially digest nitrogen-poor plant material, converting it into a protein-rich food source for the termites.
In return, the termites poop out small pellets called mylospheres, which contain fungal spores and therefore help the fungi colonies to grow. As a result, many underground termite nests contain fungal gardens, or “combs,” where these colonies have been nurtured.
In the new study, researchers describe the discovery of several fossilized termite nests in Tanzania’s Rukwa Rift Basin, three of which contained fungal combs. By analyzing the DNA they were able to extract from this material, the researchers dated the fossil fungus gardens at around 31 million years old.
Not only does this provide some staggering new insights into the age of termite agriculture, but it also yields important clues about how nutrients may have been distributed across Africa since this ancient practice first evolved.
In a statement, study co-author Nancy Stevens explained: “The origin of this behavior likely had a profound effect on how nutrients were concentrated across the landscape, influencing the evolution of Africa's biota.” For instance, because a huge proportion of the decaying wood found in this part of the continent is digested by termites, understanding the processes involved in this digestion over the past several million years could be vital to our understanding of the local history of carbon cycling.
2