Early Human Ancestors Had Plant-Based Diets, Research Suggests

A significant revelation about the dietary habits of early human ancestors suggests a strong reliance on plant-based foods rather than meat consumption. Evidence from fossilised teeth of Australopithecus africanus has provided a clearer picture of their dietary preferences. These findings, based on the chemical composition of tooth enamel, indicate that this early bipedal species, existing over 3 million years ago, may have subsisted largely on vegetation and possibly other non-meat sources of energy.

Study Analyses Fossilised Teeth for Clues

According to a study published in Science, researchers analysed nitrogen-bearing organic material within the enamel of fossilised teeth from Australopithecus africanus. A total of 43 specimens from the Sterkfontein caves in South Africa, including seven individuals of the species, were examined. The nitrogen isotopic ratios present in the samples were compared to those of other extinct mammals from the same site and to modern African mammals. These comparisons revealed that the early humans' diet was variable but lacked a significant proportion of mammalian meat.

Implications for Early Human Evolution

As explained by Dr Tina Lüdecke, geochemist at the Max Planck Institute for Chemistry, to Science News, the findings provide insights into the dietary behaviours of early ancestors. The absence of a meat-rich diet suggests that adaptations such as bipedalism, shorter snouts, and the ability to thrive in savanna ecosystems likely preceded the consumption of high-protein meat. These traits are believed to have played a role in early human survival and ecological success.

Possible Protein Sources Beyond Meat

Dr Lüdecke further noted that occasional consumption of meat or energy-rich termites by A. africanus cannot be ruled out. Termites, being a reliable food source, might have contributed to their diet without influencing the nitrogen isotopic markers significantly. Observations of modern apes fishing for termites reinforce this possibility.

This research lays the groundwork for future investigations into dietary transitions among later human species, potentially shedding more light on the role of diet in human evolution.