Archaeological research once again dispells the widespread belief that our Paleolithic ancestors were primarily meat-eaters, revealing instead that they were sophisticated plant food processors who thrived on a diverse diet thousands of years before the advent of agriculture. The study, published in the Journal of Archaeological Research by researchers from the Australian National University and the University of Toronto Mississauga, demonstrates that early humans were grinding wild seeds, pounding starchy tubers, and detoxifying bitter nuts as far back as 170,000 years ago.
"We often discuss plant use as if it only became important with the advent of agriculture," explained Dr. Anna Florin, co-author of the study titled "The Broad Spectrum Species: Plant Use and Processing as Deep Time Adaptations." According to Phys.org, the research fundamentally challenges the popular narrative of Paleolithic humans as hyper-carnivorous hunters.
However, new archaeological discoveries from around the world are telling us our ancestors were grinding wild seeds, pounding and cooking starchy tubers, and detoxifying bitter nuts many thousands of years before this," Florin added.
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Grinding stones were a 'major evolutionary success' as they allowed people to unlock the energy in plants by making flour. (José-Manuel Benito Álvarez/ CC BY-SA 2.5)
The Broad Spectrum Species Hypothesis
The research introduces a compelling alternative to the traditional Broad Spectrum Revolution hypothesis, which suggested that humans only diversified their diets around 10,000 years ago due to environmental pressures and population growth. Instead, the study proposes the "broad-spectrum species" hypothesis, arguing that dietary flexibility and plant food processing have been fundamental human characteristics throughout our evolutionary history. This ability to process plant foods allowed early humans to unlock essential calories and nutrients, enabling them to colonize and thrive in diverse environments across the globe.
Dr. Monica Ramsey, the study's other co-author, emphasized that processed plant foods were crucial to early human survival. "This ability to process plant foods allowed us to unlock key calories and nutrients, and to move into, and thrive in, a range of environments globally," Ramsey stated in a press release. She colorfully summarized the findings:
"Our species evolved as plant-loving, tool-using foodies who could turn almost anything into dinner."
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Archaeological Evidence of Ancient Food Processing
One of the primary challenges in recognizing the importance of plant foods in ancient diets has been the preservation bias in the archaeological record. Animal remains, particularly bones, survive far better than plant materials over millennia. However, recent discoveries across multiple continents have revealed extensive evidence of sophisticated plant food processing dating back far earlier than previously imagined. Researchers have analyzed plant macrofossil assemblages that show evidence of diverse processing techniques, including cooking, peeling, fat extraction, pounding, and roasting.
These processing activities were often employed in multi-step, labor-intensive sequences that demonstrate remarkable technological sophistication. By processing plant foods through various methods, early humans were able to extract nutrients and energy more efficiently, improve palatability, and enhance digestibility. The thermal processing of plant foods has been documented at early human and Neanderthal sites in Africa, Southwest Asia, and southern Europe dating back as far as 170,000 years ago.
Map of all archaeological sites with direct evidence for early plant food use, dating from ≥35 kya, as well as, Ohalo II; listed in chronological order. (Florin & Ramsey/Journal of Archaeological Research)
Implications for Human Evolution and Modern Diets
The findings have profound implications for understanding human evolution and the popular modern "paleo diet" movement. Contrary to the meat-centric narrative often promoted by paleo diet advocates, the research demonstrates that humans have never been hyper-carnivores. Instead, our ancestors exhibited remarkable dietary flexibility, adapting their food choices to available resources and environmental changes. This adaptability, particularly the ability to process diverse plant foods, directly contributed to our evolutionary success as a species.
The research team's work reveals that processed plant foods were not a late addition to human diets prompted by agricultural development, but rather a fundamental component of human nutrition throughout our existence. This challenges the premise of strict paleo diet interpretations that emphasize heavy meat consumption while minimizing the importance of plant-based foods, particularly those requiring processing. The evidence suggests that our ancestors were omnivorous opportunists who skillfully exploited whatever food resources their environments provided, using innovative technologies to make these resources more nutritious and accessible.
Top image: Tribe of Prehistoric Hunter-Gatherers Wearing Animal Skins Grilling and Eating Meat in Cave. Source: Hunman/Adobe Stock
By Gary Manners
References
Florin, S.A., et al. 2025. The Broad Spectrum Species: Plant Use and Processing as Deep Time Adaptations. Journal of Archaeological Research. Available at: https://link.springer.com/article/10.1007/s10814-025-09214-z
Phys.org. 2025. Archaeological study challenges paleo diet, revealing humans have long eaten 'processed plant foods'. Available at: https://phys.org/news/2025-12-archaeological-paleo-diet-revealing-humans.html
Discover Magazine. 2025. Early Humans Mastered Plant Processing 170,000 Years Ago, Challenging the Paleolithic Meat-Eater Myth. Available at: https://www.discovermagazine.com/early-humans-mastered-plant-processing-170-000-years-ago-challenging-the-paleolithic-meat-eater-myth-48340
