Eddie Gonzales Jr. – AncientPages.com – No evidence of meat consumption inhuman ancestors like Australopithecus, shows a new research published in the scientific journal Science.
Left: One of the sampled molars. Source; Right: Australopithecus africanus male (replica) “Enfant de Taung”; Discovered in Botswana 1924 by Raymond Dart. CC BY-SA 3.0
Researchers from the Max Planck Institute for Chemistry in Germany and the University of the Witwatersrand in South Africa (Wits University) looked at carbon and nitrogen isotopes bound to tooth enamel in fauna from an approximately 3.5-million-year-old site that includes several Australopithecus fossils.
These early hominins – researchers analyzed seven Australopithecus individuals – primarily relied on plant-based diets, with little to no evidence of meat consumption. Australopithecus that lived in southern Africa between 3.7 and 3.3 million years ago.
Animal resource consumption, especially meat, is a crucial turning point in human evolution. This protein-rich food is linked to increased brain volume and tool development. However, direct evidence of when and how early ancestors began consuming meat remains elusive.
Tooth enamel from Australopithecus was discovered in the Sterkfontein cave near Johannesburg, within South Africa’s “Cradle of Humankind,” known for early hominin fossils. Researchers compared isotopic data from Australopithecus with tooth samples from coexisting animals like monkeys, antelopes, hyenas, jackals, and big cats.
Tooth enamel preserved dietary signatures
“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. Lüdecke has led the “Emmy-Noether Junior Research Group for Hominin Meat Consumption” at the Mainz-based Max Planck Institute for Chemistry since 2021 and is an Honorary Research Fellow at the Evolutionary Studies Institute of the University of the Witwatersrand in Johannesburg.
Hand-drawn illustration of one of the seven sampled molars (StW-148) of Australopithecus. Dom Jack, Max Planck Institute for Chemistry
She regularly travels to Africa to sample fossilized teeth for her analysis. Wits University owns the Sterkfontein Caves and is the custodian of the Australopithecus fossils.
When animals digest food, biochemical reactions favor the “light” isotope of nitrogen (14N). As a result, their degradation products contain high proportions of 14N. Excreting these “light” nitrogen compounds through urine, feces, or sweat increases the ratio of “heavy” nitrogen (15N) in the body compared to their food.
This means that herbivores have a higher nitrogen isotope ratio than the plants they consume, while carnivores in turn have a higher nitrogen isotope ratio than their prey.
Nitrogen isotope ratios have long been used to study the diets of modern animals and humans in hair, claws, bones and many other organic materials. However, in fossil material, these measurements have previously been limited to samples that are only a few tens of thousands of years old due to the degradation of organic material over time.
Lüdecke used a technique from Alfredo Martínez-García’s lab at the Max Planck Institute for Chemistry to measure nitrogen isotope ratios in fossilized tooth enamel millions of years old.
Evidence of mostly plant-based food
Researchers found that nitrogen isotope ratios in Australopithecus tooth enamel were consistently low, akin to herbivores and much lower than carnivores. They conclude the diet was largely plant-based, unlike Neanderthals who hunted large mammals later. While occasional consumption of animal protein like eggs or termites cannot be ruled out, evidence points to a predominantly vegetarian diet.
Further research on fossilized tooth enamel
Lüdecke’s team plans to expand their research to other sites in eastern and southern Africa, collecting more data from different hominin species and time periods.
“This method opens exciting possibilities for understanding human evolution and can answer crucial questions, such as when our ancestors began eating meat and if this was linked to increased brain volume,” according to Alfredo Martínez-García from the Max Planck Institute for Chemistry.
“This work is a major step in understanding animal diets and trophic levels over millions of years. The research shows clear evidence that its diet lacked significant meat. We are honored this pioneering method was applied at Sterkfontein, a site contributing to science 89 years after Robert Broom discovered the first hominin fossils,” commented Professor Dominic Stratford, Director of Research at the Sterkfontein Caves and co-author of the paper.
Written by Eddie Gonzales Jr. – AncientPages.com – MessageToEagle.com Staff Writer
