Home / C. Nature, biology and evolution / Part DIR
"Eating meat made us evolve."
even if meat had been decisive in human evolution, an adaptive past doesn't dictate present morality. And the claim itself is disputed: a 2022 study showed that the apparent increase in evidence of meat-eating after the emergence of Homo erectus disappears once research effort is accounted for. Cooking, not just meat, stands out as a strong explanation.
Short answer
Even if meat helped our ancestors, that doesn't tell us what to do today. Our ancestors also lived without medicine and anesthesia, and no one wants to go back to that. And the claim itself is debated: a 2022 study showed that the apparent increase in evidence of meat-eating in the time of Homo erectus disappears once research effort is accounted for. Cooking food, including plants, is another strong explanation.
For children
Long ago, our ancestors did many things to survive: they slept in caves, had no medicine and hunted. That helped our species get here. But today we live differently: we have houses, medicine and food at the store. What was needed in the past doesn't have to be repeated forever.
"If what helped us evolve is mandatory, should we go back to living in caves?"
Como pode aparecer
"Without meat, we'd still be in the trees."
"Our brains grew thanks to meat."
"Your ancestors didn't get smart eating lettuce."
"Do you want to undo millions of years of evolution?"
"Meat was essential to human encephalization."
"It's natural to eat meat." (which is C1)
The strongest version
"Without meat, we'd still be in the trees. Our brains grew thanks to meat."
Strongest version (steelman):
- P1Eating meat provided nutrients and energy that allowed the human brain to grow.
- P2We owe our intelligence and our civilization to that past.
- CSo eating meat is a legitimate part of what made us human, and there's no reason to give it up.
The strong version rests on the hypothesis known as "meat made us human", which has been very influential in anthropology. It deserves respect as a scientific hypothesis.
The argument is valid. Its soundness fails because P1 is disputed and because, even if true, it doesn't lead to the conclusion: a fact about the past isn't a norm for the present.
Full answer
- a
Reconstruction and diagnosis
The argument moves from a hypothesis about the past to a rule about the present:
Claim Type Status Meat contributed to the evolution of the brain Scientific hypothesis Disputed So eating meat today is legitimate Moral conclusion Doesn't follow from the hypothesis - b
Where the argument breaks
1. The past doesn't dictate the present.
Many things that helped our ancestors survive aren't obligations today, and some would be unacceptable. Moving from "it was useful" to "it should continue" is Hume's law (C1).
2. The hypothesis is disputed.
In 2022, Barr and colleagues analyzed 59 site levels in eastern Africa, between 2.6 and 1.2 million years ago. They concluded that the apparent increase in evidence of meat-eating after the emergence of Homo erectus disappears once sampling effort is accounted for: the most studied sites show more evidence because they were studied more.
3. There are alternative explanations.
The anthropologist Richard Wrangham argues that cooking food, including tubers and other plants, was decisive in freeing up energy for the brain. Several factors probably contributed.
4. Even if true, the hypothesis says nothing about the present.
What our ancestors needed to survive in environments without agriculture tells us nothing about what we need with supermarkets and alternatives.
5. We also owe a debt to cooperation and empathy.
If the argument held, we should equally value the capacities that, according to anthropology, were decisive for our species, such as cooperating and caring for the vulnerable.
- c
Data and sources
Source What it says Note Barr et al., 2022, *PNAS* The increase in evidence of meat-eating after Homo erectus disappears once sampling effort is accounted for 59 site levels in eastern Africa, from 2.6 to 1.2 million years ago Wrangham, *Catching Fire* (2009) Cooking food was decisive for human evolution Basic Books; the thesis is debated among anthropologists - d
The strongest counter-reply: meat is still the ideal food
The most serious version says that, if meat was important in evolution, our bodies are still adapted to it, and removing it from the diet may carry risks.
- e
Why the counter-reply doesn't reach the conclusion
It becomes a health argument.
And current evidence shows that well-planned vegan diets are adequate (family G).
Adaptation isn't necessity.
The human body adapts to varied diets; that's what being an omnivore means (C3).
The moral question remains.
Even if meat were ideal, that wouldn't answer whether it's just to get it at others' expense.
Reasoning errors
Logical
Is the form valid?
Hume's law (from is to ought)
Genetic fallacy
Epistemological
Does the evidence support it?
Hypothesis treated as fact
Moral
Is the criterion coherent?
Anachronism
Biases
Confirmation bias
Accepts the hypothesis that confirms the habit without knowing the dispute
General literature on confirmation bias
Extrapolations
The principle being tested is: "what helped the species evolve should continue".
If it applied to…Violence between groupsTap to see
It should continue, if it helped groups survive
No one accepts this
If it applied to…Nomadic lifeTap to see
We should go back to it
Absurd
If it applied to…Cooking plantsTap to see
It would also be mandatory, if the cooking hypothesis is right
The argument doesn't favor only meat
Contradictions
Housing, medicine and work have changed completely.
Industrially bred chickens and pigs didn't exist.
The capacity to question what we do is part of the same history.
What the argument gets right
What is true
Human evolution is fascinating, and there are good reasons to think animal foods played some role in it, alongside cooking and other changes. Understanding our history matters, and the subject deserves to be studied without prejudice.
But
But the past explains where we came from, not where we should go. If evolution gave us the capacity to think about what we do, using that capacity is as human as any ancestral habit.
Connections
Usually comes before
Usually comes after
References
Science
- No sustained increase in zooarchaeological evidence for carnivory after the appearance of *Homo erectus*. *PNAS*, 119(5).
- Catching Fire: How Cooking Made Us Human.