Seven Reasons Why We Have NOT ‘Evolved’ to Eat Meat

portrait of Albert EinsteinHow many times have you heard someone justify their behavior based on the illogical premise that history somehow makes it right and assures its ethical legitimacy into the future? In fact, throughout history influential leaders and thinkers have used this same troubled logic to defend slavery, genocide, the oppression of women, racism, and discrimination based on a whole host of irrelevant criteria including sexual orientation, religion, color and now species.

In my discussions with people both online and in person, I find this interpretation of history and evolution to be one of the most common “apologies” for meat eating I hear these days. I see it as yet another way to avoid honestly confronting the moral issue of using and killing animals for food in an age when it is not necessary. Some actually sympathize with the position of vegans and vegetarians, yet still default to this argument which explains perhaps why 95% of us continue to blindly follow the cultural norms reinforced in us since childhood.

But when we are open to taking a critical look at what we have been taught, the modern myth of humans evolving to eat meat can be challenged on several levels. Here are a few of them:

1. Because we are highly evolved moral beings, averse to violence and suffering

If evolution teaches us anything at all, it teaches us that our moral consciousness and our emotional intelligence are a result of highly developed areas of our brain that afford us these faculties. “… Humans are the only animals that can intentionally structure the patterns of our lives according to a basic set of self-aware moral ideals,” writes journalist and history professor James McWilliams. “This ability, which is generally premised on reducing unnecessary pain and suffering, happens to be the foundation of human civilization.” (1)

2. Because Einstein said so

Ironically the idea that humans have somehow evolved to eat meat stands in stark contrast to the evolutionary and ethical theory of one of the greatest scientific minds who ever lived, Albert Einstein. Einstein argued that humankind would need to evolve to vegetarianism to essentially save himself and the planet. “Nothing will benefit human health and increase the chances for survival of life on earth as much as the evolution to a vegetarian diet.” (2)

So if the argument favoring history carries so much weight for most of us, will a mainstream move to vegetarianism as Einstein predicted ever occur? I think so. For one thing, the interpretation of history that meat eaters use to justify meat eating is selectively referenced from those historical sources that support the practice of meat-eating, while ignoring the rest of our history — namely our close ancestral relatives who were primarily or entirely herbivores.

3. Because so called progressives should think progressively about animals too

Even more ironic still is how otherwise progressive-minded people today continue to support the oppressive forces in our society with their eating habits, the same forces that they have adamantly opposed in other areas of their life — in their political leanings, in their religious and spiritual beliefs, in the kind of media and entertainment they seek, in the sort of books and magazines they read, etc. Still the oppression of animals remains unexamined for most progressives, and their diets reveal a deep denial of this oppression. But even this recalcitrance appears to be softening. Victoria Moran, author of Main Street Vegan, recounts that at one point her friend Michael Moore was “anti-vegan” but is now on the vegan path.

4. Because glorifying the history of humankind’s baser instincts thwarts evolution

Yet even in the face of these exciting new developments, groups like the Weston A. Price, Foundation argue that evolution essentially has a gun to our heads to consume animal products (Horn, Meat Logic). Other variations on the “we’ve always eaten animals” logic include the popular Paleo diet, whose fan sites unearth a vast ancestral mythology on the rituals of eating animals, referencing allegedly scientific, anthropological and cultural studies to prove it. Prehistoric humans and their ancestors ate some amount of meat. There’s no question about that. However, an in-depth analysis by science writer Rob Dunn published in the Scientific American reports on recent studies indicating that Human Ancestors Were Nearly All Vegetarians. But, again, is what our ancestors ate really relevant to the very different circumstances we face today regarding our food choices and lifestyles? We are no more compelled to eat like our ancestors than we are to practice cannibalism, rape, slavery, murder, or any of the other violent traditions which are all an unfortunate part of our human legacy.

5. Because by focusing on our potential to do good now, we overcome the oppressive tendencies of our past

All this talk of what is right for us to eat based on past examples distracts us from dealing with the here and now, over which we have complete control. No one is arguing that we don’t have a long history of hunting and eating animals. The more timely question is why, in an age when meat eating is unnecessary (for the vast majority of the human population), would we want to focus on what our ancestors ate some 10,000 or more years ago? To paraphrase author Colleen Patrick Goudreau, why would we want to base our ethics for eating on our paleontological ancestors whose lives were dictated by a vastly different set of circumstances and about whom we still have many unanswered questions? Certainly there are lessons to learn from history on many levels, but in relating historical facts to present circumstances, context and relevancy are everything.

6. Because the lessons from history strongly support the opposite

When confronting the person who argues his case based on history, I say, first, agree with that arguer wholeheartedly. Then explain how the history and evolution of other social justice movements can instruct and galvanize us regarding the future of the vegan/animal rights movement. One common thread that runs through all of these movements is that they were ultimately successful in permeating mainstream culture and society.

They may have begun as fringe movements whose followers were ridiculed and dismissed as extremists, but their leaders ended up being canonized in the history books and described as pioneers who popularized their social movements. And many of these leaders clearly articulated the need for both human and non human animal rights, including Cezar Chavez, Martin Luther King Jr., and Alice Walker. Filmmaker and activist James LaVeck makes a compelling case for how the British anti-slavery movement serves as an example and inspiration for the contemporary animal rights movement in his presentation, Let’s Not Give Up Before We Get Started.

7. Because our appetite for justice is far stronger

In the words of Victor Hugo, “There is nothing more powerful than an idea whose time has come.” It appears that we are standing on the threshold of an era when the tyranny of history is about to be dealt yet another serious blow. As the vegan/animal rights movement continues to gain momentum, our deplorable and largely unchallenged legacy of treating animals as property, currency, objects and cheap, disposable pieces of meat is coming under greater scrutiny than ever before in our history. This makes the infamous statement, “man has evolved to eat meat,” seem even more hopelessly out-of-touch and reactionary, revealing an attitude that clings desperately to the past and fears change, even when that change promises to reconnect us with the most fundamental and universal principle of justice and respect for all. I believe justice will ultimately prevail in the end.

(1) James McWilliams, an excerpt from his essay, Morality, Biology, Complicity.

(2) For more on Einstein’s views on vegetarianism, see

Get an email alert when posts like this one are published.

Interested in republishing this article? Read our requirements first!

About Robert Grillo

Robert Grillo is the director of Free from Harm which he founded in 2009 to expose the food industry’s exploitation of animals and foster greater empathy for farmed animals. As an activist, author and speaker, Grillo focuses awareness on the animal’s experience and point of view, drawing on insights from sociology, psychology, popular culture, ethics and social justice to bridge the gap between humans and other animals. As a marketing communications professional for over 20 years, Grillo has worked on large food industry accounts where he acquired a behind-the-scenes perspective on food branding and marketing. His new book, Farm to Fable: The Fictions of Our Animal Consuming Culture, reveals how popular culture uses a variety of fictions that condition us to consume animal products and perpetuate fasle perceptions of animals that make us feel better about exploiting them


  1. Pingback: 12 Beliefs We Have About Animals That Lead To More Of Deaths Than Ever | VegToday

  2. Pingback: Don't Hurt Me: Why "The Ghosts In Our Machine" Will Change Your Life

  3. Pingback: Q&A: What are the major advantages to Paleo Diet Recipes? | Dieting Diva

  4. Well let me put a spin on this perception. Carnivores have specifically modified and evolved teeth made to tear and rip flesh. They are the canine and incisor teeth. The herbivores have only flat molar teeth needed to grind plants and grains down to swallow. Look at the human jaw that all of us have now had 100 years ago and even had 2000 years ago. We have canine and incisor teeth in our jaws. We DO also have molars but if you want to argue that point than I will compromise and say that if anything we fall under the third option which is the Omnivore. We eat both animal flesh and plants and grains. If we were meant to be only vegitarians then we would only have molar(Flat) grinding teeth. Now, That explains the genetic and physical makeup of the human body. This is one opinion about the moral application of our so called violent, oppressive behaviour. Creationists believe we were created in the image of God by God for God. But then God gave US the animals and the plant life for US. We were also given the right to govern, raise, take care of, or basically DO with them what WE please. Well, we decided that we will USE them as we deem fit. One of those ways is to gain nutrients from them by ingesting them. Plus, moral or not, Humans were given sentience, a soul, and “higher intelligence”. We have yet to be told or proven to that the animal kingdom was ever given this sentience or soul. Most like they were not. They were given to us and placed here on earth for OUR recreation, food, entertainment, or however someone wants to define it. One thing is for sure right now, and has been since the beginning, Humans are the only living things that have displayed an actual soul/sentience, or self-awareness. Animals are animals not humans. Humans are animals too but also Humans.

    • Hello there. You are confusing sentience, the basic physiology of feeling pain and pleasure, with having a “soul.” Sentience is a scientific term, a state of being, of having subjective awareness. There is no dispute in the scientific community that non human animals are sentient in the same manner that we are. In fact, a consortium of 432 of the world’s leading nueroscientists just signed on to the University of Cambridge’s Declaration of Non Human Consciousness. See for details. Sentience is the bedrock of the ethical argument for animal rights. All that is needed to justify not being used as a resource is to possess sentience. You don’t need to have a soul to be sentient. And you don’t need to have a soul to have the right to live free of being exploited by others. For a concise definition of sentience and why it is important to understand exactly what this means, please see Lastly, it is not very objective to use Christianity or the Bible as a justification for exploiting animals as our resource. You can justify almost any act and cite something from the Bible that supports it. But how about the cardinal rule, the Golden Rule? If CHristianity says anything about morality, it says to treat others as you would like to be treated. Any distortion from this core belief seems to be betrayal of it, and worse a justification to oppress animals for any purpose we see fit.

    • And what’s more, we do not need to eat animals. There are close to a billion vegetarians on this planet to prove that. One could therefore argue that God gave us the ability to be veg and not use animals for this purpose. ALl the nutrients we need are in plants. Perhaps God made it that way. In any case, whether you are religious or secular, the facts are the same.

    • As a human molecular geneticist I felt I had an obligation to point out that you in no way explained the genetic make-up of the human body at all, not even to mention DNA…..or a single gene….or even half a gene!!

      • Congratulations. You realize that this is not a scientific argument. It’s an ethical, evolutionary one. And yet science has studied the so called “empathy gene” quite extensively for those who actually think empathy needs scientific validation to be “credible.” A simple google search will turn up exhaustive results. Response like yours are so common, overlooking the big picture by focusing on a distraction.

        • Erm I think u got the wrong end of the stick. I was referring to JohnMichaels comment “That explains the genetic and physical makeup of the human body”. i.e. JohnMichael is talking bollocks.

          I’m vegan, Buddhist and am a Robert Grillo follower.

          • I sure did! I was wondering how DNA factored into this (without having read the comment in question). I’m becoming far too cynical today. My apologies!

        • No worries, I’ve just discovered this great website and all the interesting and useful resources on it. Keep up the good work 🙂

  5. I would also like to add that the grain required to feed livestock in America for one day is enough to provide every person on earth with two loaves of bread! We could stamp out world hunger for good…imagine it, that’s a world I want to live in.

  6. Robert,

    I would like to add some important points in favor of your stance. Historically, humans have been opportunistic eaters, meaning they would eat whatever they could get their hands on which included meat, fruit, nuts, seeds, plants, and also bugs and grubs. Now to say we historically evolved eating meat, this IS a known fact. However, we did not evolve TO eat meat – people seem to forget that evolution is a continuous process. We have not evolved, we ARE EVOLVING. We are now and always will be evolving and therefore have not evolved to be anything, especially meat eaters. If this were true, then there would be no vegans/vegetarians and we would all be meat eaters. Because our intelligence has evolved and we are no longer at the mercy of nature and have very convenient grocery stores (obviously not all of us have this luxury) to buy a large selection of plant food products from, we can indeed change the course of our own evolution toward a plant-based diet. We do not require meat to survive because we can get all of our required amino acids from plants, and current meat and dairy based diets in the US are the cause of numerous health problems of which there is plenty of evidence of this online so I won’t go into it here. Instead, we can make the moral choice to stop exploiting species for the simple act of pleasing our taste buds and evolve to be highly conscious and compassionate beings. I believe there is a natural desire for empathy and respect for life that trumps the desires of our taste buds among those people who are aware of what goes on in factory farms and have a compassionate heart.

    Death is a part of life and that should not be detestable in itself. Indigenous people lived relatively in balance with the land and had a deep connection to the earth because they got their food directly from their environment and understood how all of life was connected. The animals they hunted were free, they had their own lives and could freely go about their lives and reproduce, etc. and many indigenous people have been known to say prayers of thanks, sadness, and forgiveness for their necessities during hunts to the Creator and to the animals spirits who gave their lives so bravely so that another may live. What is very different today about our meat eaters and the historic view of meat eaters is that today we have no connection to the earth, to where our food comes from, it happens in some out of the way place where people can’t see what goes on, because the people who do it know that it is detestable. We farm our meat, we have made animals our slaves, bred them for our purposes. They never get to be free, enjoy their lives, bond with their young, all they do is suffer and then get killed in a very violent way that damages their souls. There is no balance, there is no connection, they are just some product at the grocery store. Now you might be concerned that I brought up souls, but it truly is important in this argument. The reason that anyone can commit violence upon another individual, desire to control it, to chain it up, to enslave it, whether it be animal or human, is only because they see themselves as separate from that individual. It is only when people, like indigenous peoples, who understand the connection and balance that exists in all of life and that there is only one Creation can there be a mutual respect for life and never a desire to do harm unless it is a necessity to survive. I do not begrudge meat eaters for being meat eaters, I begrudge them for contributing to the enslavement of other beings when it is not a necessity.

    Another important point to note here is that we did NOT evolve eating dairy, grains, and the massive amount of sugar most people consume these days. Diets will change over time and change is inevitable. There is a movement under way that can be best explained as a raising in human consciousness. This has been slow, but it is evident throughout history, with the abolition of slavery, women’s sufferage, civil rights, gay rights, and now animal rights. There is a natural evolvement of the human consciousness to reconnect to the fact that all life is connected, and that all life is sacred. We are moving to be more compassionate, more desiring for peace in our society. Some people can’t see this, but it is there for sure. With this knowledge, and the knowledge of the health detriments of eating meat and dairy, more and more people will alter their diet to reflect compassionate choices. As a vegan, I now get much more enjoyment out of my food than I ever did before because I know I made a compassionate choice and I put the needs of others before my own desires.

  7. Pingback: When Moral Relativism Becomes a Justification to Exploit Animals

  8. Pingback: Responding to the Most Common Defenses for Eating Animals: Case 1 — Do Not Judge Me

  9. Why do you even engage with these arguments like this when they’re just informal fallacies and hilariously vulnerable to counter-examples. Saying we should eat meat because we’ve evolved to do so is an argument in the general form;

    We evolved to do X.
    We ought to do what we evolved to do.
    Therefore we ought to do X.

    X is eating meat but it’s also living in African Savannas and not wearing very much in the way of clothing. Clearly the implied premise; ‘we ought to do what we evolved to do’, should be rejected because we like living in warm houses, wearing warm clothes, and, evidently, using computers.

    I see people trying to reject the first premise, either claiming that we didn’t evolve to eat meat or that we somehow evolved to not eat meat, and I can’t help but wonder why on earth you would waste time doing such a thing.


    “Because we are highly evolved moral beings, averse to violence and suffering”

    Relies on the same faulty premise that ‘we ought to do what we evolved to do’; better to reject it outright that do this.

    This is a side point but the ‘evolutionary argument against naturalism’ may be of interest here. Essentially that; “If evolution teaches us anything at all, it teaches us that our moral consciousness and our emotional intelligence [cannot be] a result of highly developed areas of our brain that afford us these faculties.”

    “Because Einstein said so”

    Appeal to authority!

    “Because so called progressives should think progressively about animals too”

    No true Scotsman!

    “Because glorifying the history of humankind’s baser instincts thwarts evolution”

    What? Is this an attempt to reject the first premise by claiming that we didn’t evolve to eat meat or attempt to claim that not eating meat somehow represents being ‘more evolved’?
    Either way, the first is, as I’ve said, a waste of time, while the second, well, evolution doesn’t work that way.

    “Because by focusing on our potential to do good now, we overcome the oppressive tendencies of our past”

    This is the only point you should have made.

    “Because the lessons from history strongly support the opposite”

    Toupee fallacy! How many social movements do you think we don’t hear about precisely because they didn’t get “canonized in the history books”?

    “Because our appetite for justice is far stronger”

    This is more of a conclusion that a seventh point.

  10. We evolved/were created many billions of years ago*. And, we do need some animal protein**.

    * theyflydotcom.

    ** Gorillas stop eating veges. when they have a craving for meat, and will then consume a rodent before resuming their veges.


    • Is this a joke? Humans haven’t even been around for a million years, no mammals have been around more than a few million. The earth is 7 billion years old, life as basic as bacteria did not occur for billions of years, and animals for even longer after that. You have no knowledge of biology and yet you’re trying to tell people about it? That’s awful, you need to do some actual research first before making such absurd claims. Human beings need no animal proteins and live longer when they don’t, there is nothing vital within an animal’s body that a human cannot get somewhere else.

      And no, mountain gorillas only eat leaves and no animals at all, and lowland gorillas sometimes eat termites, but they don’t stop eating plants until they devour another animal, are you sure you’re not thinking of king Kong or something?

      • A joke? This is a post about ethics, not biology. Are you commenting the author or another commentator?

        • I concur and you are correct.
          Heart disease is the #1 leading cause of death in the US. Guess what the #1 cause of heart disease is? Fatty Plaque. Gee how does that get there? Eating animals. Mayo Clinic~

          “While cardiovascular disease can refer to many different types of heart or blood vessel problems, the term is often used to mean damage caused to your heart or blood vessels by atherosclerosis (ath-ur-oh-skluh-ROW-sis), a buildup of fatty plaques in your arteries. This is a disease that affects your arteries. Arteries are blood vessels that carry oxygen and nutrients from your heart to the rest of your body. Healthy arteries are flexible and strong. ” Meat is muscle and your food cries. Meat eaters are definitely intellectually challenged. I swear the stuff makes them duLL.

  11. Pingback: por qué no somos carnívoros « mqh2

  12. Pingback: Six Reasons Why the Natural Order Argument Does Not Justify Meat Eating

  13. Pingback: Five Reasons Why Meat-Eating Cannot Be Considered a 'Personal Choice'

Comments are now closed.