Did eating meat give humans bigger brains? New study reveals when our ancestors started consuming it

A reconstructed model of Australopithecus sediba displayed at the Neanderthal Museum in Germany. (Image: Neanderthal-Museum, Mettmann/ Wikimedia Commons)

Scientists have long debated how humans evolved larger brains. A new study suggests early ancestors may not have relied on meat as much as believed. The answer lies in ancient teeth.

Researchers examined fossil teeth from Australopithecus species in South Africa. These fossils, around 3.5 million years old, were found in Sterkfontein Caves. Scientists studied nitrogen isotopes in the enamel to determine diet patterns.

Nitrogen-14 and nitrogen-15 occur naturally but in different amounts. Predators accumulate more nitrogen-14 than plant-eaters. By analysing these isotopes, researchers assessed how much meat early hominins consumed.

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Mostly plant-based diet
Results showed early hominins had nitrogen levels similar to herbivores. This suggests their diet was largely plant-based with minimal meat consumption. However, researchers noted occasional meat-eating could not be ruled out.

Earlier studies suggested regular meat consumption began around 2 million years ago. Evidence includes stone tools used for butchering and animal bones with cut marks. The oldest known butchering site dates back 2.9 million years in Kenya.

Revisiting evolution theories
The study challenges the idea that eating meat was essential for human brain development. Neanderthals, who emerged 250,000 years ago, were top-level carnivores. However, early hominins may not have relied on meat as much.

Researchers stress that more studies are needed. Their findings could reshape views on how diet influenced human evolution.