Important human traits such as large brains emerged in Homo erectus about two million years ago. According to the widespread “meat made us human” hypothesis in Paleoanthropology, the evolutionary transition to modern humans is often linked to a major dietary shift involving an increase in meat consumption.
However, new research led by the George Washington University calls into question this hypothesis, by arguing that the increase in archeological evidence for meat eating can largely be explained by greater research attention to that time period rather than fundamental shifts in hominid behavior.
“Generations of paleoanthropologists have gone to famously well-preserved sites in places like Olduvai Gorge looking for – and finding – breathtaking direct evidence of early humans eating meat, furthering this viewpoint that there was an explosion of meat eating after two million years ago,” said study lead author W. Andrew Barr, an assistant professor of Anthropology at the George Washington University.
“However, when you quantitatively synthesize the data from numerous sites across eastern Africa to test this hypothesis, as we did here, that ‘meat made us human’ evolutionary narrative starts to unravel.”
By compiling and analyzing data from nine major research areas in eastern Africa, including 59 sites dating between 2.6 and 1.2 million years ago, Professor Barr and his colleagues have found no sustained increase in the relative amount of evidence for a major shift to meat eating with the emergence of Homo erectus. These results suggest that previous intensive archeological sampling of places where meat eating played a large role, rather than overall changes in human behavior, could explain the prevalence of the “meat made us human” hypothesis in Anthropology.
“I’ve excavated and studied cut marked fossils for over 20 years, and our findings were still a big surprise to me,” said study co-author Briana Pobiner, a research scientist in the Human Origins Program at the Smithsonian’s National Museum of Natural History.
“This study changes our understanding of what the zooarchaeological record tells us about the earliest prehistoric meat-eating. It also shows how important it is that we continue to ask big questions about our evolution, while we also continue to uncover and analyze new evidence about our past.”
“I would think this study and its findings would be of interest not just to the paleoanthropology community but to all the people currently basing their dieting decisions around some version of this meat-eating narrative. Our study undermines the idea that eating large quantities of meat drove evolutionary changes in our early ancestors,” concluded Professor Barr.
The study is published in the journal Proceedings of the National Academy of Sciences.