Human intellect, say scientists, developed when we moved away from our all-vegetarian diet. Until we began eating protein and carbohydrate-rich meat, our metabolic resources were absorbed by energy-demanding digestive systems that had to process vast amounts of vegetation.
About 1.8 million years ago, we stopped being vegetation foragers, and began eating meat, fat and bone marrow.
“Such easily digested foods need small stomachs and intestines, which use less energy. That surplus fed our brains, which began to grow significantly,” say researchers Dr Leslie Aiello of London’s University College, and professor Peter Wheeler of John Moores University at Liverpool. second wave of human brain increases began around 400,000 to 500,000 years ago when we began to use fire.
“Cooking is technological way of externalising part of the digestive process,” say the researchers. “Cooked food requires even less digesting and this further reduced the size of our guts, permitting greater increases in brain size,” they add. What does it all mean?
Now of course, we’re clever enough to choose to be vegetarians.
Agri experts warn New Zealand’s food and fibre future could arrive by default rather than by design
Management Editorial Team
June 24, 2026
Despite near universal optimism in the rural sector, a panel of New Zealand’s leading food and agri minds say the sector must be intentional about its future path if it’s to successfully navigate the social, economic, environmental and technological forces impacting its operating environment.
