omnivores: “Humans Are Omnivores with Canine Teeth and Front-Facing Eyes” Flashcards
This deck parallels the briefing at vbriefings.org/omnivores
About this Deck: About this Deck: “Humans Are Omnivores with Canine Teeth and Front-Facing Eyes”
This deck parallels the briefing at vbriefings.org/omnivores
– There are no formal citations here, although sources may be mentioned. Full citations with links are provided in the briefing.
– It would be best to read the briefing before studying these cards. Reading the briefing first provides understanding and context.
What is the briefing titled “One Person is Powerless to Make a Difference” about?
This briefing shows why veganism’s validity isn’t tied to humans being omnivorous, having canine teeth, or front-facing eyes.
Provide a high-level summary of the briefing on being omnivorous?
The validity of veganism doesn’t rely on humans being natural herbivores or having specific traits.
Modern science confirms that plant-based eating is healthy and can mitigate some diseases, rendering arguments about natural diets irrelevant. \
Canine teeth and front-facing eyes, often cited to justify meat consumption, serve purposes unrelated to carnivorous eating, exposing flaws in the “natural” diet claim.
Place the “we’re omnivores” objection to veganism in its larger context.
Humans adapted to consume whatever was available in their environment—whether plants, meat, or other food sources—ensuring survival by taking advantage of the most accessible options at any given time.
While understanding our evolutionary past helps explain what we are capable of eating, it does not dictate what we should eat in the context of health, sustainability, or ethics.
What key points are made in the “omnivores” briefing (7)?
- The case for veganism does not depend on humans being natural herbivores or having specific physical traits.
- The presence of canine teeth is not an indicator of dietary requirements.
- Science provides evidence that early humans ate mostly plants.
- The notion of a natural diet is problematic.
- Our inability to kill and eat animals without tools is telling.
- A plant-based diet’s ability to lower the risk of chronic disease suggests that meat is not optimal for health.
- Front-facing eyes are not necessarily indicative of predator status.
Explain why the case for veganism does not depend on humans being natural herbivores or having specific physical traits.
A scientific consensus affirms that vegan diets can provide more than sufficient nutrition for human health.
So even if humans were natural omnivores and our teeth and eye locations supported that assertion, the science is clear that a strictly herbivorous vegan diet can be not only adequate but also beneficial to our health.
The case for veganism has nothing to do with this issue. Simply put, the case for veganism is that it’s ethically wrong to cause unnecessary harm to animals.
Because it’s not necessary to eat animal products for nutrition, any claims that we are natural omnivores are rendered meaningless in this context.
Why is the presence of canine teeth in humans irrelevant?
The validity of veganism does not depend on humans’ physical traits.
Name four herbivorous animals who have sizable canines.
Hippopotamuses, gorillas, camels, and saber-toothed deer.
What are sizable canines in herbivores often used for?
Defense.
Describe the canines in humans and how they are used.
The relatively short, blunted canines in humans can assist in biting into hard, crunchy plants (such as apples) and ripping vegetable matter, preparing the food for grinding by the other teeth.
What are human canines not adequate for?
Human canines are not adequate for killing prey or tearing raw flesh for eating.
Why does Dr. Colin Barras believe archaeologists may overemphasize the role of meat in ancient human diets?
Because butchered animal bones are more likely to be preserved at dig sites, while edible plants decompose and are less likely to survive.
According to Rob Dunn in Scientific American, what kind of diet did human ancestors have for most of the last thirty million years while our guts were evolving?
A primarily vegetarian diet, focused on eating pieces of plants.
What did Rob Dunn in Scientific American say about gut evolution?
Our guts evolved over millions of years as generalist primate guts designed mainly for processing plants.
Explain why notion of a natural diet is problematic.
Even if the concept of a natural diet had made some sense in the context of gatherers and hunters, it would have lost its meaning since the invention of agriculture, which has selectively bred both plant and animal species.
Also, to claim that humans are natural omnivores, one must define what ” natural ” means in this context. If by “natural” you are referring to the ability to obtain nutrients, then humans are omnivores, as we can digest both plants and meat. But, as shown earlier, that still cannot negate the case for veganism.
If you mean it’s natural because it’s nutritionally the best diet for humans, then you are on shaky ground. An increasingly large body of research, as mentioned and cited above, supports the contention that the closer we are to a varied herbivorous diet, the greater our general health and the lower our risk for a multitude of chronic diseases.
Finally, the claim that humans are natural omnivores is an example of the naturalistic fallacy—being natural doesn’t make something ethically or nutritionally sound.
Why would the concept of a natural diet make even less sense since the invention of animal agriculture?
Even if the concept of a natural diet had made some sense in the context of gatherers and hunters, it would have lost its meaning since the invention of agriculture, which has selectively bred both plant and animal species.
Why is the argument that a diet is “natural” because it is nutritionally best for humans considered weak?
An increasingly large body of research, as mentioned and cited above, supports the contention that the closer we are to a varied herbivorous diet, the greater our general health and the lower our risk for a multitude of chronic diseases.
Why is the claim that humans are natural omnivores an example of the naturalistic fallacy?
Because being natural does not automatically make something ethically or nutritionally right.
How does the need for tools to kill and eat animals challenge the idea that eating meat is part of a natural human diet?
It shows that humans lack the natural physical traits of carnivores, meaning eating meat requires technology, not natural anatomical ability, which challenges the idea that eating animals is inherently natural for humans.
What major health organizations have stated that vegan diets are nutritionally adequate and protective, and how does this challenge the natural diet fallacy?
Mayo Clinic, Harvard Public Health, Cleveland Clinic, Kaiser Permanente, NewYork-Presbyterian, and the Academy of Nutrition and Dietetics, along with nutrition organizations in Canada, England, and Australia, have all confirmed that well-planned vegan diets are suitable for all life stages and protect against chronic disease—showing that what is “natural” (eating meat) is not necessarily what is healthiest, directly challenging the idea that a natural diet is automatically the best diet for humans.
How does the argument that humans’ front-facing eyes prove we are natural meat eaters rely on the natural diet fallacy, and what does scientific research actually show about why primates evolved front-facing eyes?
The argument relies on the natural diet fallacy by assuming that front-facing eyes must indicate a natural need for a predatory meat-heavy diet, but research shows that primates evolved front-facing eyes primarily for manipulating plant foods, seeing through dense foliage, and navigating tree canopies—not for hunting prey.
This reveals that eye placement alone does not determine a species’ “natural” diet.
How does Percy Bysshe Shelley’s book A Vindication of Natural Diet relate to the natural diet fallacy?
Shelley, though a poet rather than a scientist, argued that comparative anatomy shows humans are naturally suited to a vegetable diet—an example of the natural diet fallacy, since what is “natural” does not automatically mean it is best for health or ethics.
In conversations about what is a natural diet, why is it important to shift the focus away from debating what is “natural”?
Because veganism is not about what’s “natural,” but about what is ethical—minimizing harm to animals—and beneficial for health and the environment.
During a conversation on natural diets, what questions can you ask to steer the discussion back to animal ethics?
—“Does a cow that screams in pain while being killed care about our irrelevant justifications?
—“If someone was kicking a dog, would you say, ‘it’s OK, humans are natural omnivores?’” or would you try to stop them? “
—“Even if humans are natural omnivores, how does that justify causing unnecessary suffering when we can choose healthy alternatives?”
Why? This forces them to confront the moral inconsistency of their position.
During a conversation on natural diets, what questions can you ask to challenge the idea that being omnivorous justifies eating animals?
—“What matters isn’t whether we can digest meat—it’s whether eating animals is necessary or ethical. Since we can be healthy without animal products, how does being omnivores justify harming animals?”
—“Humans are omnivores, meaning we can eat both plants and animals. But just because we can do something doesn’t mean it’s right. Would you say that because humans can steal, stealing is justified?”
Why? This shifts the conversation from biology to ethics, making their argument irrelevant to the case for veganism.
During a conversation on natural diets, what questions can you ask to show that veganism isn’t about what’s “natural”?
—“Even if humans were evolved to eat some meat in the past, modern science shows that a well-planned vegan diet is perfectly healthy and even reduces disease risk. So why should we base our ethics on outdated survival strategies?”
—”If we only ate what was ‘natural,’ wouldn’t we refuse to take medicine, or cook our food? “
Why? This forces them to reconsider why “natural” should dictate modern choices.
During a conversation on natural diets, what can you say and ask to show why canine teeth don’t prove we’re meat eaters?
Some people believe that having canine teeth proves we’re designed to eat meat. But many herbivores also have large canines, and human canines are nothing like those of carnivores.
—“Hippos, gorillas, and saber-toothed deer all have huge canines, but they’re herbivores. So having canines doesn’t mean an animal is meant to eat meat.”
—“Our canines are short, blunt, and weak. They help us bite into apples and nuts, not tear raw flesh. If canines made someone a carnivore, would you say a hippo is a meat eater?”
Why? This discredits the idea that canines determine diet.
During a conversation on natural diets, what can you say and ask to show that front-facing eyes aren’t just for hunting?
—“Primates, our closest relatives, have forward-facing eyes, yet they primarily eat plants. If eye placement made someone a predator, wouldn’t gorillas be meat eaters?”
Why? This challenges the assumption that forward-facing eyes = carnivorous diet.
During a conversation on natural diets, what can you say and ask to show that early humans ate mostly plants?
Many assume that because our ancestors ate meat, we should too. But evidence suggests that early humans primarily ate plants.
—“Scientific American reports that our ancestors were nearly all vegetarians for most of the last 30 million years while our digestive system was evolving. If evolution determines what we should eat, wouldn’t that mean we should eat mostly plants?”
Why? This corrects the assumption that humans evolved as heavy meat eaters.
During a conversation on natural diets, what can you say and ask to reframe the “natural diet” argument?
Even if we knew exactly what diet was “natural” for humans, that wouldn’t determine what’s best today.
—“Calling something ‘natural’ doesn’t make it right. Violence and disease are natural too—should we accept those?”
—“If eating meat was ‘natural,’ why do plant-based diets consistently show better health outcomes and lower rates of chronic disease?”
Why? This forces them to question why they’re relying on a flawed argument.
During a conversation on natural diets, what can you say and ask to point out that humans need tools to kill and eat animals?
Unlike natural carnivores and omnivores, humans cannot hunt, kill, or eat animals without tools.
—“Lions and wolves kill prey with their bodies alone—claws, teeth, speed. If we were natural carnivores, why do we need spears, knives, and fire to eat meat?”
—“If you had to catch and kill an animal with your bare hands and eat it raw, could you? If not, does that sound like something we’re naturally designed to do?”
Why? This highlights how our reliance on tools suggests we’re not natural meat eaters.
During a conversation on natural diets, what can you say and ask to show that plant-based diets are better for health?
If eating meat were truly optimal for humans, we wouldn’t see so many health benefits from removing it.
—“The Mayo Clinic, Harvard, and Cleveland Clinic all say plant-based diets reduce the risk of heart disease, cancer, and diabetes. If we were designed to eat meat, why does removing it improve health?”
—“The Academy of Nutrition and Dietetics says a well-planned vegan diet is healthy for all life stages. If meat was necessary, wouldn’t they say otherwise?”
Why? This makes them question whether meat is as “natural” as they think.
During a conversation on natural diets, what can you say and ask to appeal to our current situation?
Focus on what’s possible today, not what was necessary in the past.
—“If you can be perfectly healthy on a plant-based diet, why justify harming animals just because you can eat meat?”
—“If our ancestors ate meat to survive, but we don’t need it anymore, what’s stopping us from choosing a more ethical and sustainable diet?”
Why? This shifts the conversation away from outdated survival justifications.
Why do we not use Dr. Milton Mills Research paper, “The Comparative Anatomy of Eating,” a paper frequently referenced in vegan advocacy?
The paper attempts to show that humans are natural herbivores.
This research has been criticized for oversimplifying human anatomy, exaggerating intestinal length, cherry-picking traits, ignoring key digestive adaptations like stomach acidity, and overlooking the evolutionary flexibility that makes humans natural omnivores.
At least some of those criticisms seem valid.
