As early as 100,000 years ago, wild olive trees provided food and fuel for early Mediterranean people, according to investigations into deposits in two caves in northern Morocco. They suggest that Stone Age residents ate olive fruit there and then smashed the pits. They then used the high-energy fragments together with olive wood for long-lasting and little smoking fires in the caves, the researchers suspect.
The olive tree is almost a symbol of the Mediterranean region: the ancient crop has retained its importance to this day and is part of the cultural heritage of the people there. For millennia, it has provided them with food, fuel, and substances used medicinally or cosmetically. It is well known that the tree or olive oil also played an important role in mythology and religions. The earliest evidence of its targeted agricultural use and breeding goes back to around 6000 years ago. The extent to which the wild form of the olive tree (Olea europaea) was used by humans before that, however, is more of a mystery.
100,000 year old cremation remains
As for the era of the last Ice Age, it seems clear that the heat-demanding plant could not exist in most of its current range. During the cold period, areas of retreat apparently formed on the Atlantic coast of what is now Morocco. This is now also documented by the plant remains reported by the international research team led by Laurent Marquer from the Institute of Botany at the University of Innsbruck. But the significance of the findings goes beyond paleobotany, as they come from two caves in the Rabat-Temaria region of northern Morocco that are already known as anthropological sites: bones and stone tools used by early modern humans from the period have been found there more than 100,000 years ago.
As part of their study, Marquer and his colleagues examined remains of burned wood and charred fragments of plant cores extracted from sediments in the caves. Apparently, these are traces of the fires that once warmed the inhabitants of the caves and were used to prepare food. The dating results showed that they burned around 100,000 years ago. More detailed analyzes of the material then revealed which plants the material came from: it was therefore mostly olive tree wood and the fragments of the plant pits turned out to be olive pits without a doubt. It is thus becoming apparent that people used to collect twigs or wood from the wild olive trees as fuel – and also the olives.
Food and ideal fuel?
While scientists cannot definitively prove that the pulp was eaten by the hunter-gatherers, it is likely. For why should they have left this nutritious fare unused? “It seems possible that entire olive branches were thrown into the fire and the fruit hanging from them simply burned,” says Marquer. “However, we would have had to find whole cores instead of the many fragments. So everything suggests that people first ate the fruit and then consciously broke the pits in order to burn them more efficiently,” says the scientist.
As he explains, this method seems plausible due to the special burning properties of the nuclei. Because of their high oil and lignin content, broken olive pits produce a particularly slow-burning fire that is very suitable for cooking. The dried core fragments also produce smokeless flames, which the scientists say would have been of great benefit to the cave dwellers.
According to them, the findings now provide interesting information about life and the use of resources by people in Northwest Africa 100,000 years ago. “And they complete the story of the iconic Mediterranean olive tree,” conclude Marquer and his colleagues.
Source: University of Innsbruck, specialist article: Nature Plants, doi: 10.1038/s41477-022-01109-x