in this video Dr. Miki Ben-Dor explains why we are carnivores.
🎙️ Dr. Miki Ben-Dor is a paleoanthropologist, researching the association between diet during the Paleolithic era and human evolution. He has a Ph.D. in Archaeology from the University of Tel Aviv, a B.A. in Economics, and an MBA. He is an author and researcher with over 15 published studies.
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Summary
In this comprehensive lecture, the speaker explores whether humans are biologically adapted to be carnivores and what implications this has for protein consumption. Using a variety of scientific data including evolutionary biology, anthropology, genetics, and physiology, the talk challenges commonly held views about human diets, particularly the reliance on ethnographic studies of recent hunter-gatherers that do not reflect Paleolithic conditions. Key evidence points to humans’ physiological and morphological adaptations that align more closely with carnivorous rather than herbivorous or omnivorous traits.
The speaker highlights a dramatic decrease in the size of prey animals over the last 2.5 million years, largely coinciding with the rise of Homo species, indicating that humans have impacted carnivore guilds significantly by hunting large game. This has influenced dietary patterns as large animals are rich in fat, which was a critical component for survival since protein intake has biological upper limits.
Physiological adaptations discussed include the structure of the human gut (shorter large intestine and longer small intestine), the ability to run and throw projectiles effectively (traits linked to hunting), and special fat metabolism traits that differ from other primates. Genetic adaptations such as variation in the salivary amylase gene suggest a secondary, more recent adaptation to starch consumption but not a primary driver of evolutionary diet.
The lecture also critiques the use of ethnographic data from modern hunter-gatherers like the Hadza, whose diets are shaped by modern ecological changes, such as the diminished presence of large game due to human activity. Archaeological data and nitrogen isotope analysis of human remains consistently show humans consuming high-trophic-level diets similar to carnivores.
The speaker concludes that humans have consumed a protein-rich diet—35 to 50 percent of calories from protein—for around a million and a half years, often limited by fat availability rather than protein. This has significant implications for modern dietary recommendations, suggesting that higher protein intakes are safe and may be closer to our evolutionary norm, contrasting with contemporary lower protein consumption levels.
Highlights
- 🦴 Human evolutionary history shows a decline in large prey size coinciding with human hunting impact.
- 🔬 Nitrogen isotope studies place humans at the trophic level of carnivores.
- 🍖 Human gut morphology favors digestion of animal protein and fat over fibrous plants.
- 🏃♂️ Adaptations to endurance running and throwing support a predatory lifestyle.
- 🧬 Genetic adaptation to starch consumption is recent and variable, secondary to primary carnivorous traits.
- 🦛 Modern hunter-gatherer diets are not representative of Paleolithic diets due to ecological changes.
- 🍽️ Protein intake ranging 35–50% of calories was typical and is safe for humans based on evolutionary evidence. Key Insights
🦕The Dramatic Decrease in Prey Size Reflects Human Hunting Pressure Over the past 2.5 million years, average terrestrial prey size dropped by more than 80%, likely due to humans outcompeting or hunting large carnivores and herbivores. This reshaped food availability and forced humans to exploit a narrower, fat-rich subset of prey, underscoring their role as apex predators.
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Genomic Differences Highlight Dietary Flexibility but Not Reversal from Carnivory Humans’ range in salivary amylase gene copies (2 to 16) is a sign of recent adaptation towards starch digestion, but these genes are not fixed as would be expected if plant-based diets were an ancient specialization. This suggests that starch consumption is a secondary trait layered atop a fundamentally carnivorous biology.
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Physiological and Anatomical Adaptations Show Specialization Towards Carnivory The shorter large intestine relative to small intestine and specialized teeth confirm humans are not adapted to digest large quantities of fibrous plants but are optimized for protein and fat from animals. The shoulder morphology facilitating throwing, and fat cell composition further support a predator lifestyle.
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Protein Intake is Biologically Limited but Historically High Humans face a protein ceiling (35–50% of daily calories) beyond which excess protein causes negative health effects (rabbit starvation). Paleolithic humans maximized fat extraction from large prey to maintain energy balance, indicating a diet rich in both protein and fat but limited by protein’s upper bounds.
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Archaeological Evidence of Specialized Fat Extraction Techniques Demonstrates Reliance on Animal Fat The complex process of bone grease extraction late in the Paleolithic signals fat scarcity in prey and underscores how critical fat was to energy needs, beyond just meat consumption, further illustrating that plant fats were insufficient substitutes.
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Modern Hunter-Gatherer Data Are Poor Proxies for Paleolithic Nutrition Ethnographic records, such as those of the Hadza people, are misleading due to their limitation to much smaller prey. Changes in ecosystems over time (decline of elephants, baobab trees affected by elephant populations) mean they do not reflect ancestral dietary conditions.
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Implications for Modern Diet: Higher Protein Consumption is Safe and Evolutionarily Supported Contemporary diets with 10–15% protein do not reflect human evolutionary history where twice that intake was common and safe. This challenges current dietary guidelines and suggests revising protein quotas upward could align better with our biology and health outcomes.
This detailed exploration synthesizes multidisciplinary evidence, strongly advocating that humans are biologically adapted to a carnivorous diet with significant reliance on animal fat and protein, which carries important implications for understanding our evolutionary past and optimizing current nutrition strategies.
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