• New research suggests that early humans may have eaten little to no animal-based food.
• By studying nitrogen isotopes found in fossilised Australopithecus teeth, it was determined that the diet of this species was largely plant-based.
• While Australopithecus may have eaten some animal-based protein this would have been limited to eggs and termites.

There is a common belief that the addition of meat to the diet of early humans helped catalyse our evolution but new research throws that theory into a tail spin.

Scientists from the University of the Witwatersrand (Wits) and the Max Planck Institute for Chemistry in Germany published new research in the journal Science last week that suggests our ancestors may not have eaten meat at all and lived off of a vegetarian diet.

The researchers examined teeth from Australopithecus fossils in Southern Africa, and found little evidence of these early humans eating meat.

Mrs Ples, an iconic fossil discovered in Sterkfontein, is a member of this early hominid family. This was determined by analysing isotope data from the tooth enamel of these ancient people. This data was compared to animals that lived alongside our ancestors including money, antelope and large predators such as hyenas, jackals and big cats.

As an article from Wits explains, herbivores tend to have a high nitrogen isotope ratio in their fossils due to their diet of nitrogen rich foods while carnivores have an even higher nitrogen isotope as their prey is loaded with nitrogen.

These isotope levels can be observed in fossils but until recently observing this isotopes was tough given that organic material degrades over time. That is, unless the isotopes are protected by an extraordinarily tough substance.

“Tooth enamel is the hardest tissue of the mammalian body and can preserve the isotopic fingerprint of an animal’s diet for millions of years,” says geochemist Tina Lüdecke, lead author of the study.

Studying the levels of nitrogen isotopes in the teeth of Australopithecus fossils, the researchers discovered that nitrogen isotope levels were consistent with those found in herbivores and not carnivores.

This is not to say that our ancestors ate no animal-based protein as they may have sought out eggs or insects such as termites but the nitrogen isotope levels suggest that the diet of these early humans was largely plant based.

“This work represents a huge step in extending our ability to better understand diets and trophic level of all animals back into the scale of millions of years. The research provides clear evidence that its diet did not contain significant amounts of meat. We are honoured that the pioneering application of this new method was spearheaded at Sterkfontein, a site that continues to make fundamental contributions to science even 89 years after the first hominin fossils were discovered there by Robert Broom,” says Professor Dominic Stratford, Director of Research at the Sterkfontein Caves and co-author of the paper.

This research is bound to trigger more research into our history as a species as researchers try to narrow down when exactly early humans began eating meat as a core part of their diet. That may have been Homo habilis, a species that closely resembled Australopithecus but came later in our evolution.

We’ll leave that research to smarter folks than ourselves.

[Image – Hung Diesel from Pixabay]