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Authors: Loren Cordain
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that human beings were meant to be vegetarians runs contrary to every shred of evolutionary evidence from the fossil and anthropological record. We owe a huge debt to lean meat. In fact, scientific evidence overwhelmingly suggests that if our ancient ancestors had eaten a meatless diet, we wouldn’t be where we are today. I wouldn’t have become a scientist, you wouldn’t be reading this book, and we would all look a lot more like our nearest animal relative—the chimpanzee.
How can this be? Chimps are hairy, and they have a big gut. They swing from trees. Well, yes, but about 5 to 7 million years ago, so did our prehuman ancestors. The evidence is that the family tree forks—and humans moved into a category all their own. But genetically speaking, we are only about 1.7 percent different from the chimp.
Chimps are mostly vegetarians (although they do eat a few insects, bird eggs, and the occasional small animal), and they have the big, protruding belly characteristic of vegetarian animals (horses and cows, for example, have big bellies, too). Apes need large, active guts to extract the nutrients from their fiber-filled, plant-based diet.
About 2.5 million years ago, our ancestors began trading in their big guts for bigger brains—to the point where today our bellies are about 40 percent smaller than those of chimps and our brains are about three times larger. The turning point came when our ancestors figured out that eating animal food (meat and organs) gave them much more energy. Over the years, their bellies began to shrink—because they didn’t need the extra room to process all that roughage. All the energy formerly needed by the gut was diverted to the brain, which doubled and then tripled in size. Without nutrient-dense animal foods in the diet, the large brains that make us human never would have had the chance to develop. Meat and animal foods literally shaped our genome.
Interestingly, just before the same period when human brains began to expand, something new came on the scene: tools—crude stone weapons, and knives that our ancestors used to butcher animal carcasses and later to hunt. We know this because of telltale cut marks that have been found on the bones of fossilized animals and from evidence (a classic example is the 125,000-year-old spear crafted from a yew tree found embedded between the ribs of an extinct straight-tusked elephant in Germany) compiled at thousands of archaeological sites worldwide.
At first, humans were not terribly good hunters. They started out as scavengers who trailed behind predators such as lions and ate the leftovers remaining on abandoned carcasses. The pickings were slim; ravenous lions don’t leave much behind, except for bones. But with their handy tools (stone anvils and hammers), our early ancestors could crack the skulls and bones and still find something to eat—brains and fatty marrow.
Marrow fat was the main concentrated energy source that enabled the early human gut to shrink, while the scavenged brains contained a specific type of omega 3 fat called “docosahexaenoic acid” (DHA), which allowed the brain to expand. Docosahexaenoic acid is the building block of our brain tissue.
Without a dietary source of DHA, the huge expansion of our brain capacity could never have happened. Without meat, marrow, and brains, our human ancestors never would have been able to walk out of tropical Africa and colonize the colder areas of the world. If these people had depended on finding plant foods in cold Europe, they would have starved. In a landmark series of studies, my colleague Mike Richards, at Oxford University, studied the bones of Paleolithic people who lived in England some 12,000 years ago. Their diet, Richards confirmed, was almost identical to that of top-level carnivores, such as wolves and bears.
Hunting Big Game
Why would any sane person get close enough to poke a spear into a sharp-hoofed, kicking, and snorting 600-pound horse—much less a raging
How can this be? Chimps are hairy, and they have a big gut. They swing from trees. Well, yes, but about 5 to 7 million years ago, so did our prehuman ancestors. The evidence is that the family tree forks—and humans moved into a category all their own. But genetically speaking, we are only about 1.7 percent different from the chimp.
Chimps are mostly vegetarians (although they do eat a few insects, bird eggs, and the occasional small animal), and they have the big, protruding belly characteristic of vegetarian animals (horses and cows, for example, have big bellies, too). Apes need large, active guts to extract the nutrients from their fiber-filled, plant-based diet.
About 2.5 million years ago, our ancestors began trading in their big guts for bigger brains—to the point where today our bellies are about 40 percent smaller than those of chimps and our brains are about three times larger. The turning point came when our ancestors figured out that eating animal food (meat and organs) gave them much more energy. Over the years, their bellies began to shrink—because they didn’t need the extra room to process all that roughage. All the energy formerly needed by the gut was diverted to the brain, which doubled and then tripled in size. Without nutrient-dense animal foods in the diet, the large brains that make us human never would have had the chance to develop. Meat and animal foods literally shaped our genome.
Interestingly, just before the same period when human brains began to expand, something new came on the scene: tools—crude stone weapons, and knives that our ancestors used to butcher animal carcasses and later to hunt. We know this because of telltale cut marks that have been found on the bones of fossilized animals and from evidence (a classic example is the 125,000-year-old spear crafted from a yew tree found embedded between the ribs of an extinct straight-tusked elephant in Germany) compiled at thousands of archaeological sites worldwide.
At first, humans were not terribly good hunters. They started out as scavengers who trailed behind predators such as lions and ate the leftovers remaining on abandoned carcasses. The pickings were slim; ravenous lions don’t leave much behind, except for bones. But with their handy tools (stone anvils and hammers), our early ancestors could crack the skulls and bones and still find something to eat—brains and fatty marrow.
Marrow fat was the main concentrated energy source that enabled the early human gut to shrink, while the scavenged brains contained a specific type of omega 3 fat called “docosahexaenoic acid” (DHA), which allowed the brain to expand. Docosahexaenoic acid is the building block of our brain tissue.
Without a dietary source of DHA, the huge expansion of our brain capacity could never have happened. Without meat, marrow, and brains, our human ancestors never would have been able to walk out of tropical Africa and colonize the colder areas of the world. If these people had depended on finding plant foods in cold Europe, they would have starved. In a landmark series of studies, my colleague Mike Richards, at Oxford University, studied the bones of Paleolithic people who lived in England some 12,000 years ago. Their diet, Richards confirmed, was almost identical to that of top-level carnivores, such as wolves and bears.
Hunting Big Game
Why would any sane person get close enough to poke a spear into a sharp-hoofed, kicking, and snorting 600-pound horse—much less a raging
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