Prehistoric humans stored bone marrow like tins of soup 400,000 years ago.
Prehistoric humans living in a cave in Israel between 420,000 and 200,000 years ago were storing bone marrow so they could eat it at a later time, scientists have discovered. This shows early hominins understood that food might not be available in the future and had the foresight to do something about it.
The Qesem Cave, which is about 7.5 miles from Tel Aviv, was identified as a site of early human occupation almost 20 years when road construction cut through it. Since then, a huge amount of archaeological evidence has been unearthed, including tens of thousands of animal bones that were processed by our human ancestors.
In a study published in Science Advances, researchers led by Ruth Blasco, from Spain’s National Research Centre on Human Evolution, have now analyzed these bones and carried out experiments on them to show how these occupants had learned to effectively store the bone marrow for weeks and months after the animal had died.
Which hominin species—the group to which modern humans belong—was processing the bones in this way is not known. But Blasco said that whoever they were, they demonstrated many modern behaviors, including regular use of fire, recycling and food roasting. The deferred consumption of bone marrow is now another task to add to that list.
Bone marrow, the tissue found inside some bones, is highly nutritious, being higher in calories than protein or carbohydrates. As a result, it would have been a valued and significant food source for early humans. Some research even suggests that the process of extracting it has shaped our own evolution.
Blasco started working at the Qesem site in 2011. While analyzing faunal materials found there, she realized there were unusual marks on the recovered deer bones. But more evidence was needed.
After analyzing the remains of almost 82,000 animal bones from the site, the team was able to show that bone marrow was being preserved for consumption at a later date. Old, dry flesh and skin is harder to remove from a bone than when it is fresh. As a result, removing it leaves behind specific sawing marks.
“These unusual marks were identified in subsequent experiments and explained by dry skin removal,” Blasco told Newsweek. “Specifically, these marks were generated by the difficulty or effort required to remove dry skin and tendons firmly attached to the bone after a prolonged subaerial exposure of the bones.”
In experiments, researchers showed that these marks could be replicated by removing skin after two or more weeks. They also found skin removal increased after four weeks. This, the team believes, is evidence of deferred consumption of the marrow. Their experiments also show that the nutritional value of bone marrow starts to deteriorate from around six weeks after the animal’s death, Blasco said.
She said the team was surprised by the findings. “The deliberate accumulation of bones for delayed consumption of marrow implies an anticipated concern for future needs. This fact marks a threshold for new modes of Paleolithic adaptation because the foresight capacity surpasses the ‘here and now’ as a means of subsistence in a chronology of more than 300,000 years,” she noted.
Blasco says she believes this is just the start of our understanding of how early prehistoric humans were storing food for later consumption. “We would like to continue exploring the preservation and storage techniques in ancient times and how to detect them in the fossil record. This includes not only the preservation of fat but other perishable products, such as meat,” she said.