The research was done by an international group of scientists, led by researchers from the University of Bristol in the United Kingdom and including Kathleen Ryan of the University of Pennsylvania Museum of Archaeology and Anthropology.
The research was done by analyzing fatty acids that were extracted from unglazed pottery excavated from an archaeological site in Libya. The researchers found that dairy fats had been processed in the pottery vessels. This is the first definite identification of dairying practices in the African continent, by prehistoric Saharan herders. It can be very accurately dated to the fifth millennium B.C.E.
10,000 years ago, what is now the Sahara Desert, was a wet, green place; there were early hunter-gatherer people there living a semi-sedentary life. These people used pottery, hunted wild animals, and gathered wild grains. Around 7,000-5,000 years ago, the region became drier, and then the people took on a more nomadic, pastoral way of life, “as suggested by the presence of cattle bones in cave deposits and river camps.”
Domesticated animals were clearly significant to these people. Engraved and painted rock art found everywhere across the region show many vivid representations of domesticated animals, particularly cattle. Domesticated animals appeared to be very important to these people, but until now there was no clear proof that these cattle were milked.
“Researchers from the University of Bristol’s School of Chemistry, with colleagues at Sapienza, University of Rome, studied unglazed pottery dating from around 7,000 years ago, found at the Takarkori rock shelter in the Tadrart Acacus Mountains in Libya.”
Kathleen Ryan, who is a consulting scholar in the Penn Museum’s African Section, and one of the authors of this study, “had previously collected data on reference animal fats and plant remains from Kenya.”
“Though the Kenyan remains have so far not turned up any evidence of dairying there, they were valuable in that they served as controls in our study of the Libyan samples,” Ryan said.
These reference samples were used by the researchers “to inform lipid biomarker and stable carbon isotope analyses of preserved fatty acids held within the fabric of the pottery.”
“Without this collection the project would not have come to fruition in the way it has,” said Richard Evershed, a professor in Bristol’s School of Chemistry and co-author on the paper.
The researchers found that one half of the vessels had definitely been used for the processing of dairy fats. This is the first confirmation of the importance of milk to these prehistoric pastoral people, and of its early use.
“We already know,” said Julie Dunne, a doctoral student in Bristol’s School of Chemistry and lead author of the study, “how important dairy products such as milk, cheese, yogurt and butter, which can be repeatedly extracted from an animal throughout its lifetime, were to the people of Neolithic Europe, so it’s exciting to find proof that they were also significant in the lives of the prehistoric people of Africa.
“As well as identifying the early adoption of dairying practices in Saharan Africa, these results also provide a background for our understanding of the evolution of the lactase persistence gene which seems to have arisen once prehistoric people started consuming milk products.
“The gene is found in Europeans and across some Central African groups, thus supporting arguments for the movement of people, together with their cattle, from the Near East into eastern African in the early to middle Holocene, around 8,000 years ago,” she said.
“While the remarkable rock art of Saharan Africa contains many representations of cattle – including, in a few cases, depictions of the actual milking of a cow – it can rarely be reliably dated,” Evershed said. “Also, the scarcity of cattle bones in archaeological sites makes it impossible to ascertain herd structures, thereby preventing interpretations of whether dairying was practiced.
“Molecular and isotopic analysis of absorbed food residues in pottery, however, is an excellent way to investigate the diet and subsistence practice of early peoples. It’s an approach my colleagues and I have previously applied to successfully determine the chronology of dairying, beginning in the Fertile Crescent of the Near East and spreading across Europe.”
Image Credits: Roberto Ceccacci, The Archaeological Mission in the Sahara, Sapienza University of Rome; Jennifer Chiappardi for Penn Museum)