They weren’t people. They were termites. An international team led by researchers from James Cook University has discovered fungus gardens within fossil termite nests in Africa’s Great Rift Valley in 25 million-year-old sediments.
Fungus-farming termite colonies cultivate fungi in underground nests or chambers, helping to convert plant material – essentially wood – into a food source they can digest more easily. By looking at the DNA from modern termites, scientists had estimated that this ‘fungus farming’ behaviour could reach back as far as 25 to 30 million years. The new trace fossil evidence from Tanzania pushes this date back to at least 31 million years ago.
The farming behaviour could have significantly modified the environment and landscape and this discovery increases scientific understanding of environmental change and carbon cycling in ancient forests. While the cradle of termite agriculture presumably was in an African rainforest, the transition to fungiculture helped the insects to disperse to less favourable dry savannas and also to migrate out of Africa into Asia. A bit like humans, really.
The research is part of an ongoing study focused on the evolution of a poorly known portion of the Great Rift Valley. It’s another great example of Australia’s credentials as a ‘clever country’ – thanks to research that we can only maintain if universities are properly funded.