By Irene Esteban & Paloma de la Peña Alonso - The Conversation
There is a fair amount of archaeological evidence that indicates complex behaviour among our ancestors. For instance, there are bone tools that were used as hunting projectiles, for working leather or for processing plants. Ochre remnants were used for body and rock painting. But plants and their products have rarely been reported to embody this type of complex behaviour.
Now a multidisciplinary, international team of archaeologists has presented evidence that more than 200,000 years ago, at the dawn of our species (Homo sapiens sapiens) groups of humans inhabiting a cave in South Africa used grasses to create comfortable areas for sleeping and working. They also, our research suggests, understood the benefits of using ash underneath the grass to repel insects and pests.