Scientists have discovered that ancient Clovis people thrived on mammoth meat during North America’s Ice Age. Photo: Shutterstock According to scientists, the first humans who spread across North America during the last Ice Age prioritised mammoths as a primary food source. This conclusion comes from the first direct evidence of the diet of these ancient people.
Researchers analysed the diet of a woman who lived 12,800 years ago, using chemical clues found in the bones of her son, discovered in the US state of Montana. Since the 18-month-old was still nursing at the time of his death, his bones reflected the chemical signatures of his mother’s diet.
The diet break-up
Researchers found that her diet primarily consisted of meat from megafauna, the largest animals in an ecosystem, particularly mammoths. Megafauna made up 96 per cent of her diet, with mammoths accounting for about 40 per cent. The remainder of her diet included elk, bison, camels and horses. Contributions from small mammals and plants were minimal.
“Megafauna, especially the massive Columbian mammoths, offered substantial amounts of meat and energy-rich fat. One mammoth could support a community of children, caregiving women, and less mobile elders for days or even weeks while the hunters looked for their next kill,” explained archaeologist James Chatters from Applied Paleoscience, an archaeological consultancy based in Bothell, Washington.
He is the co-lead author of the study that made this discovery published last month in the journal Science Advances.
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The Clovis culture
The mother and child were discovered to be part of the Clovis culture, which dates back 13,000 years. This highly mobile and nomadic group is known for artefacts such as large stone spear points designed for hunting massive prey and big stone knives for removing meat from bones.
“These results also help us understand megafaunal extinctions at the end of the last Ice Age, indicating humans may have played a more important role than is sometimes thought,” said Ben Potter, an archaeologist at the University of Alaska Fairbanks and co-lead author of the study.
The Clovis people lived in North America during the final stages of the Ice Age, a time when a warming climate was shrinking habitats for mammoths and other large herbivores. While these animals were accustomed to predators like sabre-toothed and scimitar-toothed cats, they had never encountered human hunters before.
The Clovis people were highly skilled hunters who refined their abilities over 10,000 years while hunting megafauna.
When they arrived in North America, south of the glacial ice, they encountered prey unfamiliar to human hunters. By emphasising megafauna in their diet, these newcomers contributed to that stress, increasing the likelihood of extinction, Chatters stated.
How scientists studied the diet
Pieces of the skull and other bones from the child, informally called Anzick Boy, were discovered in 1968. Researchers conducted stable isotope analysis to investigate the protein portion of his mother’s diet, focusing on various isotopes of carbon and nitrogen.
The combination of isotopes from these elements can provide a chemical signature that indicates the type of food consumed – beef or peas, for instance. The researchers estimated that the boy’s diet consisted of two-thirds nursing and one-third solid food.
They compared the mother’s diet, as revealed by the analysis, to various omnivores and carnivores from the same period, including big cats, bears and wolves. Her diet resembled that of Homotherium, a now-extinct scimitar-toothed cat that hunted mammoths.
What are stable isotopes and what can they tell us?
Isotopes are atoms of the same element that have the same number of protons but a different number of neutrons. Stable isotopes do not decay into other elements.
They are found everywhere in our environment. The isotopes found in the food we eat and the water we drink become part of all our tissues, including our bones. By studying isotopes, scientists can understand a person’s diet and the environment they lived in.
For example, stable nitrogen isotopes can reveal what sort of diet they had (see graphic).