Meat is BAD FOR YOU! It doesn’t make evolutionarily sense…
This is another post where I question the meat vilification narrative and I delve further into a point I made on human evolution in a previous post. The meat vilification narrative doesn’t make much sense from a human evolutionary perspective.
In William Von Hippel’s book, The Social Leap, he shows how human anatomy evolved corollary with certain hunting techniques. Humans are physically weaker and slower than many animals and apes but over time early humans compensated with a greater capacity to cooperate with other humans, coupled with anatomical dexterity. This became a potent combination evolutionarily. The theory is known as the Throwing Hypothesis and originates back to when our ancestor species were forced from the dense jungles of central Africa towards the savanna, due to tectonic changes that led to vast areas of jungle drying out.
At the same time our ancestor species were evolving greater dexterity in their hands, which allowed for them to make primitive labour maximising tools. Coupled with this, the evolutionary pressure on the savanna led to Australopithecus becoming bipedal.
Bipedality combined with primitive labour maximising tools, meant australopithecus was a much better thrower. Being bipedal means you can better rotate your hips to generate power; your wrists become more flexible because the need for stiff wrists and strong arms is not needed anymore because they are not up in the trees all the time which chimpanzees are and that’s why they have very stiff wrists and strong arms.
Throwing is evolutionarily very significant to our species — it represents the capacity to kill at a distance. No other animal has that capacity. And with this capacity our early ancestors could successfully hunt animals much larger and stronger than themselves. For example, a single human cannot take down a lion or elephant by throwing rocks, but a group of humans all throwing rocks in synchronicity can take down a lion or an elephant. This method also worked very well when scavenging meat.
The fossil evidence also supports this, showing early humans hunted large animals, larger than themselves, whereas other primates only hunt smaller animals than themselves.
Paleoanthropologist Leslie Aiello, puts forth the hypothesis that eating meat led to our modern brain development*. The idea is called the Expensive Tissue Hypothesis (ETH). The hypothesis argues that around 1.5 million years ago early humans began to eat more meat; meat is a compact, high-energy source of calories that does not require a large intestinal system — think of a cows intestinal system. Leslie explains there was a definite dietary change in our ancestors to foods of higher nutritional value, which were easy to digest.
A growing brain size presented a metabolic problem for our ancestors. The brain is the most metabolically expensive tissue in the body. A gram of brain tissue takes 22 times more energy to grow and maintain than a gram of tissue from a kidney, heart, or liver. Gut tissue is the second most metabolically expensive tissue. So as our ancestor’s brains grew, their gut sizes shrank. Thus it’s likely that meat eating made it possible for humans to evolve a larger brain.
It was not just meat eating that influenced brain size growth — it was also that meat was cooked. Cooking food allowed for foods of high nutritional value to be eaten and digested more efficiently compared to other primary food sources, which are eaten by other primates. For example, meat makes up only about 3% of the average chimpanzee’s diet. Other primates spend most of their day sitting around eating and digesting, whereas early humans didn’t has this need which freed up time, and with a larger brain, due to a cooked diet may “…have been a major positive driving force to the rapid increases in brain size in human evolution”.
The fossil evidence of dental and facial structures of early humans further supports the aforementioned hypotheses. Other primate species and early hominids had strong jaws and molar-like teeth but later species were more like modern humans, with weaker jaws, smaller faces, and smaller teeth. These dental and facial structural changes correlate with the rate of cooked food that was consumed. Cooking food softens food, and therefore, strong jaws, like those in primates that eat a predominantly vegetarian diet, are not needed.
On top of this, macronutrients such as fat and protein are hard to come by — unlike vegetarian foods — in the environments where chimpanzees and other primates live. Whereas in meat they are plentiful and are essential for brain function and metabolic health. Important nutrients in meat include vitamins A and K, calcium, sodium, and potassium, but also iron, zinc, vitamin B6, and vitamin B12. These nutrients are present only in small quantities in plants and they are not as easily assimilated when in plant form, unless processed properly e.g. fermented, sprouted or slow cooked — evolutionarily this took time to learn.
Parasite historians have found through genetic analysis of a wide variety of tapeworm species that early humans and carnivores such as lions and hyenas were infected with the same types of tapeworm. This suggests lions, hyenas and early humans hunted and scavenged the same food — meat. It was originally thought tapeworms infected humans when they domesticated livestock around 10,000 years ago. However, the life cycle of tapeworms disproves this; the predator (carnivore) carries the adult tapeworm and the prey (herbivore) hosts the infective larvae. Therefore, it was humans who passed tapeworms to domesticated livestock.
As mentioned earlier, humans are unique in their social cooperation and this provides more evidence to support eating meat. In most primate cultures, there’s no food sharing between females and offspring, or between peers; but there is between modern and early humans. The difficulty of getting meat led to cooperative food sharing among early humans, strengthening the bond between a female and her offspring and influencing mate selection — successful hunters mate with more women.
Additionally, there is evidence that early humans delayed their food consumption; this is not observed in chimpanzees and other primates. This holds important implications for how early humans interacted with one another socially and shows that our brains have developed unique social functions, which developed corollary with a hunter-gather meat-eating lifestyle.
Conclusion
Overall, what this post shows to me is that given the evolutionary evidence, which I have only just scratched the surface of, shows that meat is unlikely to be as bad to your health as many Official Governmental Guidelines and Netflix documentaries make it out to be. Please don’t be afraid or hesitant to eat a bit more meat; it has been doing wonders for the majority of our existence, but it’s a bit strange why it would be failing us now…
*On a side note, I need to make clear that most scientists don’t argue that meat eating caused bigger brains, it just made bigger brains possible. There were other sociological and environmental reasons, which put evolutionary pressure on bigger brain sizes — see this paper and this one.
