New study unravels the ‘meat made us smarter’ theory

By Georgia Lambert via SWNS

How important meat was in our ancestors' evolution into modern humans has been questioned by scientists.

The evolution of human history has been well-documented and human-like traits like large brains first appear in Homo erectus nearly two million years ago.

This occurrence is often linked to the major shift in diet preferences and how meat seemed to become more prevalent.

While archaeological evidence for meat-eating strengthens dramatically after Homo erectus enters the picture, the authors of the new study claim this increase could be because there has been greater attention to this.

They added that this has "effectively skewed" the evidence in favor of the "meat made us human" theory.

Lead author, Andrew Barr, an assistant professor of anthropology from George Washington University, said: "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.

“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.”

Professor Barr and his colleagues compiled a collection of published data from nine major research areas in eastern Africa, including 59 site levels, dating back to 1.2 and 2.6 million years ago.

They then used several metrics to track hominin carnivory - the number of zooarchaeological sites preserving animal bones that have cut marks made by stone tools - along with the total count of animal bones with cut marks across sites, and the number of separately reported stratigraphic levels.

The researchers discovered that there was no sustained increase in the evidence for carnivory after the appearance of Homo erectus.

Co-author, Briana Pobiner, a research scientist in the Human Origins Program at the Smithsonian’s National Museum of Natural History, said: "I’ve excavated and studied cut marked fossils for over 20 years, and our findings were still a big surprise to me.

“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.”

The authors went on to add: "While the raw abundance of modified bones and the number of zooarchaeological sites and levels all demonstrably increased after the appearance of Homo erectus, the increases were mirrored by a corresponding rise in sampling intensity, suggesting that intensive sampling – rather than changes in human behavior – could be the cause."

In future studies, the researchers stressed the need for an alternative explanation for why certain anatomical and behavioral traits associated with modern-day humans were unearthed.

Possible alternative theories include the provisioning of plant foods by grandmothers and the development of fire for increasing the supply of nutrients through cooking.

Professor Barr said: “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.”

The study was published in the Proceedings of the National Academy of Sciences journal.