Suffolk Reporter

An international team of researchers has discovered that Australopithecus, an ancient human ancestor living over three million years ago in South Africa, primarily consumed plant-based foods. This finding, published in the journal Science, comes from an analysis of tooth enamel from seven Australopithecus fossils. The study is significant as it narrows down the timeline for when regular animal consumption increased and brain size grew among hominins.

Dominic Stratford, PhD, from Stony Brook University and the University of the Witwatersrand in South Africa, along with colleagues from the Max Planck Institute for Chemistry in Germany and other institutions, conducted this research. They analyzed stable nitrogen isotope data (15N/14N) from tooth enamel found at the Sterkfontein Caves, a site known for its rich collection of early hominin fossils.

The ratio of stable nitrogen isotopes is used to determine an animal's position in the food chain. Enrichment of 15N typically indicates a higher trophic level and consumption of animal tissue. However, conventional methods using bone collagen or dentin are limited to about 300,000 years due to decay. Recent advancements now allow for sampling enamel, which can preserve dietary isotopic fingerprints for millions of years.

Stratford explains that this advancement provided "the first direct evidence of the diet of ancient hominin fossils" and allowed exploration into when meat eating began among hominins. By comparing isotopic data from Australopithecus fossils with those of contemporary animals like monkeys and big cats, researchers concluded that while occasional meat consumption was possible, Australopithecus mainly followed a plant-based diet.

The findings suggest that changes in behavior observed in Australopithecus may not be linked to increased meat consumption. Instead, regular meat eating likely emerged later or elsewhere geographically. Stratford notes: “Overall, this work provides clear evidence that Australopithecus in South Africa did not eat significant amounts of meat three million years ago.”