Rewriting Prehistory: Archaeologists Discover Our Ancestors Were Mostly Vegetarian

A recent study has provided evidence that could rewrite our understanding of the diet of early human ancestors. Researchers from the Max Planck Institute for Chemistry and the University of Witwatersrand in South Africa analyzed the fossilized tooth enamel of seven individuals from the species Australopithecus africanus, who lived between 3.7 and 3.3 million years ago in southern Africa. Using an innovative technique to measure nitrogen isotopes in tooth enamel, the scientists found that these hominins relied primarily on a plant-based diet, with little to no evidence of meat consumption.

This discovery challenges previous theories suggesting that meat consumption was a key factor in brain development and human evolution. While Australopithecus has been associated with the use of stone tools and cut marks on bones, the new isotopic evidence indicates their diet resembled that of herbivores, suggesting that significant meat intake may have occurred at later stages of human evolution. 

The technique used in this study is particularly noteworthy because, during fossilization, organic material and nitrogen often disappear, making it difficult to analyze ancient diets. However, the new method allowed researchers to determine nitrogen isotope ratios in tooth enamel millions of years old, providing a "chemical fingerprint" of the diet of these early hominins. 

It is important to note that, although evidence points to a predominantly vegetarian diet, occasional consumption of protein sources such as eggs or insects cannot be entirely ruled out. However, the lack of significant evidence for regular meat consumption among these individuals suggests that the consistent inclusion of meat in the human diet occurred later in evolutionary history.

This discovery has significant implications for our understanding of human evolution, suggesting that the transition to a carnivorous diet, and the potential benefits it brought in terms of brain development and adaptation, occurred at a later stage. Additionally, the technique developed for this study could be applied to other fossils, helping answer key questions about the diet and evolution of our ancestors. 

In summary, the research suggests that early human ancestors, such as Australopithecus africanus, were largely vegetarian, and that significant meat consumption, with its possible implications for human evolution, happened later in our evolutionary history.