Eating meat, and hunting, have played a key role in the history of our species, Homo sapiens. Anthropologists think that a diet high in animal protein may have played a central role in fueling the evolution of our large human brains. So, to understand human evolution, anthropologists need to understand the origins of meat eating in the ancestors of our species.
One of those ancestors is Australopithecus. Several kinds of Australopithecus lived in eastern and southern Africa about two to four million years ago. Although these human ancestors walked upright like us, they were shorter than modern humans—only about four and a half feet tall. Their brains were about thirty five percent as big as ours.
In 2025, an international team of researchers published a new study that sheds light on the diet of Australopithecus. The researchers did a chemical analysis of enamel from the teeth of Australopithecus africanus remains found in South Africa’s Sterkfontein caves. They were looking for organic material containing nitrogen. By comparing the amount of two forms of nitrogen found in their samples, the researchers could tell the relative amount of meat in the diet of their subjects.
They compared their results with samples taken from the teeth of the remains of other mammals found in the caves, and teeth of modern African mammals whose diet they knew. Their conclusion was that this particular kind of Australopithecus did not have a diet rich in meat. That may mean that some important human traits, like walking upright and living on the African savanna evolved before our ancestors had a meat rich diet.
A special thanks goes to Dr. Jeremy DeSilva, Professor of Paleoanthropology, Dartmouth College, for reviewing today's episode!
Further reading
- Early human ancestors didn’t regularly eat meat
- When did our ancestors start to eat meat regularly? Fossilized teeth get us closer to the answer
- When human ancestors began eating meat remains a mystery
- Our ancestors were vegetarian three million years ago
T Lüdecke et al. Australopithecus at Sterkfontein did not consume substantial mammalian meat. Science. Vol. 387, January 17, 2025, p. 309.