The debate about when our ancestors started eating meat has taken an unexpected turn. While we’ve long associated early human evolution with meat consumption, a recent study reveals that some of our earliest ancestors stuck to a mostly plant-based diet.
The research was led by Dr. Tina Lüdecke from the Max Planck Institute for Chemistry in Germany in collaboration with researchers from South Africa.
The findings challenge our previous assumptions about early hominin diets.
Teeth hold clues of ancient diets
A team of researchers from the Max Planck Institute for Chemistry in Germany and the University of the Witwatersrand (Wits University) in South Africa analyzed nitrogen isotopes in the fossilized tooth enamel of seven Australopithecus individuals.
These fossils were recovered from the Sterkfontein Caves near Johannesburg, a site rich in early hominin remains.
By comparing these isotopic signatures to those of coexisting animals – including herbivores like antelopes and monkeys, as well as carnivores such as hyenas and big cats – the scientists established the positrons of Australopithecus in the prehistoric food web.
The nitrogen isotope ratios in the Australopithecus teeth were consistently low, closely resembling those of plant-eating animals. This strongly suggests that these early human ancestors primarily consumed a plant-based diet and did not regularly eat meat.
While the researchers acknowledge that Australopithecus may have occasionally consumed animal proteins such as eggs or insects, their findings indicate that meat was not a significant part of their diet.
Plant-based vs. meat diets
The key to this discovery lies in the analysis of nitrogen isotopes, which provide reliable indicators of an animal’s diet. When animals digest food, their bodies process nitrogen in a way that leaves distinct chemical traces.
