What did prehistoric humans consume?

Washington: Researchers have uncovered evidence of the storage and delayed consumption of animal bone marrow by prehistoric humans some 400,000 years ago. The study, which was published in the Science Advances, was led by Dr Ruth Blasco of TAU's Department of Archaeology and Ancient Near Eastern Civilisations and Centro Nacional de Investigacion Sobre la Evolucion Humana (CENIEH) and her TAU colleagues Prof Ran Barkai and Prof Avi Gopher.

"Bone marrow constitutes a significant source of nutrition and as such was long featured in the prehistoric diet," explained Professor Barkai. "Until now, evidence has pointed to the immediate consumption of marrow following the procurement and removal of soft tissues. In our paper, we presented evidence of storage and delayed consumption of bone marrow at Qesem Cave."

"This is the earliest evidence of such behaviour and offers insight into the socioeconomics of the humans who lived at Qesem," added Dr Blasco. "It also marks a threshold for new modes of Paleolithic human adaptation."

"Prehistoric humans brought to the cave selected body parts of the hunted animal carcasses. The most common prey was fallow deer, and limbs and skulls were brought to the cave while the rest of the carcass was stripped of meat and fat at the hunting scene and left there," Professor Barkai explained.

We found that the deer leg bones, specifically the metapodials, exhibited unique chopping marks on the shafts, which are not characteristic of the marks left from stripping fresh skin to fracture the bone and extract the marrow," Professor Barkai added.

The researchers contend that the deer metapodials were kept at the cave covered in the skin to facilitate the preservation of marrow for consumption in a time of need. The researchers evaluated the preservation of bone marrow using an experimental series on deer, controlling exposure time and environmental parameters, combined with chemical analyses.

The combination of archaeological and experimental results allowed them to isolate the specific marks linked to dry skin removal and determine a low rate of marrow fat degradation of up to nine weeks of exposure.

"We discovered that preserving the bone along with the skin, for a period that could last for many weeks, enabled early humans to break the bone when necessary and eat the still nutritious bone marrow," added Dr Blasco.

"The bones were used as 'cans' that preserved the bone marrow for a long period until it was time to take off the dry skin, shatter the bone and eat the marrow," Professor Barkai emphasised.

Until recently, it was believed that the Paleolithic people were hunter-gatherers who lived hand-to-mouth (the Stone Age version of farm-to-table), consuming whatever they caught that day and enduring long periods of hunger when food sources were scarce.

"We show for the first time in our study that 420,000 to 200,000 years ago, prehistoric humans at Qesem Cave were sophisticated enough, intelligent enough and talented enough to know that it was possible to preserve particular bones of animals under specific conditions, and, when necessary, remove the skin, crack the bone and eat the bone marrow," Professor Gopher explained.