As a vegan who likes to preach veganism — but perhaps that’s redundant —meat-eaters often tell me that “we evolved to be omnivores.” To their surprise, I agree with them. Though I am a vegan, my academic training is in human evolutionary biology, and I cannot let my philosophy hijack the science: Veganism is an unnatural way of life.
Our bodies evolved to kill other animals. Our musculoskeletal anatomy is perfectly tuned to throw objects with lethal speed and precision. We didn’t evolve this strange ability to throw baseballs, but to throw spears — a skill we have utilized to slaughter large mammals since the time of Homo erectus. After we abandoned the forest for the savannah, our lineage developed an expanded waist to let the upper torso twist independently, dropped shoulders to give our chest muscles more leverage, and lowered humeral torsion to allow for more dramatic rotation of the shoulder. These three adaptations made it possible for our species to whip objects through the air at speeds our ape ancestors could not hope to achieve, killing dangerous prey from a safe distance.
Similarly, we have a remarkable capacity to run long distances, a trait that is also absent in our closest cousins (who, by the way, are not vegans). Our species can run down almost any animal, so long as the distance is far enough. Our short toes, our efficient cooling system, our oversized butts, and our elastic ligaments and tendons evolved to let our species run for an obscenely long time without stopping. We gained this ability likely to exhaust our prey through persistence hunting on the savannah, chasing our bigger, stronger victims until they were unable to resist further, and then spearing them. Natural selection didn’t make us marathon runners so that we could chase down carrots.
Our body relies and thrives upon nutrients that, in nature, would typically only be found in sufficient quantities in animal products, most demonstratively, Vitamin B12. Herbivores can get B12 either through foregut fermentation or through eating their own dung — the former behavior is physically impossible for humans (the latter, perhaps, psychologically). Our ape cousins get their B12 primarily through eating insects and small animals, and humans, like our relatives, have historically relied on animal sources to fulfill this nutritional requirement. They didn’t have nutritional yeast in the Stone Age.
Everywhere you might look in the history of our species, you find animal products. There is no Eden for us to return to.
Some vegans counter that because we have an unimpressive set of canines and no claws, we must be herbivores. This ignores the fact that our closest relatives all consume some amount of animal products, and none of them have claws either. Plus, in the primate order, canines are used primarily for fighting, not for eating meat, so “Canines, though” is a non sequitur regardless of which side of the debate deploys it (gorillas consume the least animal products of our great ape cousins, and they have the most impressive canines). Worse, this argument forgets that our species is the only one on earth that chops up and cooks its food before eating it — this has allowed our species to outsource our food-processing, and downsize our dentition and digestive system. Sure, our dentition and digestive system are not exactly like those of a typical omnivore, but they’re also absolutely nothing like a typical herbivore. We aren’t typical: Unlike every other creature on earth, we’re chefs.
When a fellow vegan insists that veganism is the natural state of humanity, I have to ask them: When and where did we live naturally? Our direct ancestors — from the chimpanzees to the australopithecines to the early Homo lineage — were omnivores. And until more modern recorded history, there had never been a documented culture you could reasonably call vegan. Sure, there had been large groups of vegetarians, and every so often, a philosopher or small community would attempt full-on veganism. Still, before the 20th century, a truly herbivorous lifestyle was a rarity. Everywhere you might look in the history of our species, you find animal products. There is no Eden for us to return to.
Think: Is there any other herbivorous species where virtually every member of said species eats meat? The question itself is absurd because if there were, we would call them by a more accurate name: omnivores. Among experts in human evolution, human omnivory is as uncontroversial as our bipedality. Indeed, arguing that it is unnatural for us to eat meat is entirely analogous to arguing it is unnatural for us to walk. We have physical adaptations to do so, almost every human does so, and the fossil record shows we have always done so.
However, if you think these facts deal a mighty blow to the project of veganism, you are deluded.
First, modern-day omnivory is equally unnatural. Pumping an inbred chicken full of antibiotics, raising them in a cage barely more spacious than your laptop, and then turning them into nuggets using an automated factory line is as artificial as it gets. One can hardly defend this process, from laboratory to drive-through, by saying it’s “natural.”
Second, natural is not a synonym for healthy. It is entirely unnatural to wash your hands, get vaccinated, and visit the doctor annually — I still recommend you do all those things if you want to live a long life. Similarly, I recommend you shift to a plant-based diet: Vegans and vegetarians have dramatically lowered risks of heart disease and cancer, and we are less likely to have high blood pressure, high cholesterol, hypertension, or diabetes. Given this information, it won’t surprise you to learn that vegans generally live longer. Living a vegan lifestyle isn’t particularly natural, but neither is living past 60, and I plan to do both.
When we ask what is natural, we merely look back over our shoulders; if we want to look forward, we need to ask what is right.
Finally, and most importantly, natural does not mean moral. Many armchair ethicists seem convinced that if a behavior is natural, it is necessarily good. Philosophers call this the “Appeal to Nature” fallacy, and it can only be honestly deployed by those ignorant of how poorly our species naturally behaves. To list only a few examples:
Lying is a natural behavior in our species — the ability to deceive someone when advantageous gave your ancestors a tremendous edge in the fight for survival. But if you caught your child in a lie, you surely would not accept a lecture on natural selection as an excuse. (Though, admittedly, depending on the age of your child, such a lecture might be sufficiently impressive to distract you from your anger.)
Cheating on your partner is also an adaptive behavior: If a man can sneak in an extra child on the side, that’s a free point in the game of evolution. If a woman can successfully conceive with a man of better phenotypic quality than her current mate, she has the edge over a woman who would not attempt such a maneuver. (If you still believe that appealing to nature is valid, I would encourage you to try these excuses on your spouse.)
Perhaps worst of all, warfare is almost certainly natural in our species. Though cultural theorists might want to portray it as a socially constructed aberration, the biological literature is quite clear: Under specific circumstances, the males in our species tend to form packs and murder males from the neighboring group. This behavior cannot be solely cultural, as it appears across virtually all cultures, and it cannot be merely a fluke of our time, as it has happened throughout history. It is hardly a coincidence that the only other species on earth that reliably engages in this behavior is our closest biological relative, the chimpanzee. Would anyone dare to suggest that we should continue participating in this asinine, destructive, reprehensible behavior for the sake of living naturally?
We vegans often hear meat-eaters make the following blunder as if it were checkmate: “Humans are naturally omnivores.” Imagine, for a moment, if I were caught lying, cheating, or attacking another human, and responded with, “Humans naturally [insert unethical act here].” The truth is, living as nature intended is not merely unhealthy; it is also patently immoral. If we calibrate our moral compass towards the lives of early Homo sapiens, we will doom ourselves to backward movement across the moral map. When we ask what is natural, we merely look back over our shoulders; if we want to look forward, we need to ask what is right.
In holding humans only to the standards of their ancestors, we hold our species back. We can sort through our ancestry’s mixed bag and discard the behaviors that make life on this planet intolerable for ourselves and others.
Veganism is not natural, but it is right. When we purchase animal products, we pay for animals to live in conditions that make dog shelters look like the Ritz. On our farms, piglets are castrated without anesthesia, chicks are ground up alive in a blender on their first day of life, and baby cows are robbed from their mothers and turned into veal. The creatures humans eat and wear are electrocuted, shot in the face, stabbed in the neck, and forced into gas chambers; they scream when they die. If you treated a single dog the way farmers treat billions of animals, you would be locked up in a cell and diagnosed with psychopathy. Though veganism is often maligned as an extreme act, going vegan is merely ceasing to pay for this cruelty.
While veganism is, by definition, motivated by the desire to help animals, it helps humans, too. Though the list of humanistic reasons is too long to cover here, veganism boycotts the horrendous exploitation and abuse of slaughterhouse workers, it reduces your contribution to indigenous land theft, and it is one of the greatest lifestyle changes you can make to help stop the existential threat of climate change. Plus, veganism boycotts the most common cause of humankind’s pandemics — including coronavirus. To go vegan, your empathy need not extend past the boundary of your own species; it need only extend past yourself.
One lifestyle tortures animals, destroys the environment, and threatens the future of humanity; the other is unnatural. Which will you choose?
In holding humans only to the standards of their ancestors, we hold our species back. Natural selection merely passed us the behaviors that made our ancestors more likely to survive and reproduce; many of these behaviors cause joy and create beauty, but some of them — violent and selfish — are the cause of unconscionable suffering. We can resign ourselves to maintain our ancestral behaviors in perpetuity and live merely as another one of the great apes for the rest of history. Or, we can sort through our ancestry’s mixed bag and discard the behaviors that make life on this planet intolerable for ourselves and others. We can choose to become a truly great ape by swimming against the amoral tide of nature towards kinder lands.