New research published in the Proceedings of the National Academy of Sciences provides the first evidence for diet and subsistence practices of Neolithic East African pastoralists.
The development of pastoralism is known to have transformed human diets and societies in grasslands worldwide. Cattle-herding has been — and still is — the dominant way of life across the vast East African grasslands for thousands of years.
This is indicated by numerous large and highly fragmentary animal bone assemblages found at archaeological sites across the region, which demonstrate the importance of cattle, sheep and goat to these ancient people.
Today, people in these areas, such as the Maasai and Samburu of Kenya, live off milk and milk products from their animals, gaining 60-90% of their calories from milk.
Milk is crucial to these herders and milk shortages during droughts or dry seasons increase vulnerabilities to malnutrition, and result in increased consumption of meat and marrow nutrients.
Yet we do not have any direct evidence for how long people in East Africa have been milking their cattle, how herders prepared their food or what else their diet may have consisted of.
Significantly though, we do know they have developed the C-14010 lactase persistence allele, which must have resulted from consumption of whole milk or lactose-containing milk products. This suggests there must be a long history of reliance on milk products in the area.
To address this question, Dr. Katherine Grillo from the University of Florida and colleagues examined ancient potsherds from four sites in Kenya and Tanzania, covering a 4,000-year timeframe (from 5,000 to 1,200 years ago), known as the Pastoral Neolithic.
The researchers analyzed organic lipid residues left in the pottery and were able to see evidence of milk, meat and plant processing.
“This is the first direct evidence we’ve ever had for milk or plant processing by ancient pastoralist societies in eastern Africa,” Dr. Grillo said.
“The milk traces in ancient pots confirms the story that bones have been telling us about how pastoralists lived in eastern Africa 5,000 to 3,000 years ago — an area still famous for cattle herding and the historic way of life of people such as Maasai and Turkana,” added Washington University’s Professor Fiona Marshall.
“Most people don’t think about the fact that we are not really designed to drink milk as adults — most mammals can’t. People who had mutations that allowed them to digest fresh milk survived better, we think, among herders in Africa. But there’s a lot we don’t know about how, where and when this happened.”
“It’s important because we still rely on our genetics to be able to drink fresh cow’s milk once we are adults.”
The study shows, for the first time, that herders who specialized in cattle — as opposed to hunting the abundant wildlife of the Mara Serengeti — were certainly drinking milk.
“One of the reasons pastoralism has been so successful around the world is that humans have developed lactase persistence — the ability to digest milk due to the presence of specific alleles,” Dr. Grillo said.
Katherine M. Grillo et al. Molecular and isotopic evidence for milk, meat, and plants in prehistoric eastern African herder food systems. PNAS, published online April 13, 2020; doi: 10.1073/pnas.1920309117
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