Vegetarians will often tell you that humans did not evolve to eat meat. Take the following video:
http://www.youtube.com/watch?v=Tt72EPHpS_U
Now, I’m by no means an expert on this subject, but it doesn’t take a degree in evolutionary biology to realize that almost everything about this video is complete and utter bullshit. For starters, it lumps the world into two categories—carnivores and herbivores—when in fact human beings are by all accounts omnivores. And as an omnivore, meat is definitely on the menu.
Take, for example, the Maasai of Kenya, who along with maze-meal rely on meat, milk and the blood of cattle. Yum. And there are the Plains Indians, who along with wild fruits, roots and vegetables, ate almost every edible part of the buffalo—not just blood and bone marrow, but also raw intestines and the half-digested prairie grass they contained. A delicacy according to Lame Deer. Or how about the Chinese? Along with rice and pork, they have been known to eat monkey brains, ox penis and pretty much anything else you can imagine.
But let’s get specific. How exactly is this video bullshit? Let's take it point for point.
1. “Carnivores have long pointed jaws and large incisors for tearing at flesh. Herbivores have rounded jaws for munching vegetation.”
First of all, let's look at the chimpanzee, since it split from human evolution about 6 million years ago and is the closest living relative to humans, sharing about 94-95% of our DNA.
What do chimps eat?
Although their primary source of food is plants, the chimpanzee diet is, not surprisingly, omnivorous. Along with fruits and plants, they also eat insects, and will steal eggs and baby chicks from bird nests whenever the opportunity arises. Chimps especially love eating termites, and have ingenious methods for catching them. When fingers alone don't cut it, they craft special tools from stems and sticks to coax the termites out their mounds.
Chimps also gather into groups and hunt for meat—in their case, baby bushbuks, colobus monkeys, young baboons and other small mammals. As with humans, it is mostly the male chimpanzees that hunt, and all together meat consists of about 5% of their diet.
All together, the chimpanzees are known to eat over 200 different types of foods. They are extremely intelligent creatures capable of learning from their experience. They use different tools for hunting, breaking open coconuts or similar hard-shelled fruits, and smoking out termites and ants from their underground homes.
Which brings us to humans...
Few would argue that homo sapiens probably started out eating much like our cousin, the chimp: an omnivorous diet rich in variety. However, at some point prior to the dawn of the Paleolithic era, around 2.6 million years ago, we evolved away from a chimp diet and chimp lifestyle (as is evident from all the hunting tools unearthed by archeologists), and this shift changed our physiology. To understand this change, we should take a quick look at the physiological differences between chimps and humans.
What makes us different from chimps?
Well, aside from standing upright and having less hair (some less than others), we also have shorter intestines and much larger brains—so large in fact that passing a baby’s head through the birth canal is a matter of life and death for the mother.
Why did our brains get larger? Or an even better question: How could our brains have gotten larger?
To understand the answer to this question we must look inward, at the structure of the brain itself. The human brain is comprised of 60% fat, and not just any fat, but a specific kind of fat—omega-3 fatty acids. And since our body can't produce omega-3 fatty acids, we must get it directly from our food.
To properly form and function, the human brain (along with the components of our eyes’ photoreceptors) requires omega-3 fatty acids from the time we are still forming in our mother's belly to the day we die. Without them, we become weak and frail, eventually diseased. However, the amount of omega-3 fatty acids that our brains required to evolve in size and complexity could not be met with an herbivore diet—that is, unless our Paleolithic ancestors were cold pressing flax and hemp seeds for their oil (unlikely, given that neither agriculture nor industry had been developed).
Currently, there are two prominent theories of how we got additional omega-3s in our diet. The first theory claims that our species began eating more seafood and fish—rich sources of omega-3 fatty acids. The other theory, what I like to call the Savage Scavenger Theory, suggests that we began cracking open the skulls and bones of animal carcasses with rocks or hatchets after they had been killed by lions, and ate the omega-3 rich marrow and brains.
Since these theories are not mutually exclusive, I’m partial to believing both. I assume that like our chimp cousins, we were smart enough to exploit multiple niches and eat a wide variety of foods. In any event, as a result of eating more fish or meat (or, more likely, fish and meat), human intestines shrank and our brains grew—which corresponds neatly with the zero-sum nature of our bodies. Chimps and gorillas, on the other hand, have longer intestines, which correspond to their plant-heavy diet.
2. “Carnivores have many natural hunting skills, like night vision.”
First of all, night vision is an ability—not a skill. Skills are usually acquired or learned; abilities are often thought of as innate. And although it is true, that we don’t have night vision, we are certainly not shy on innate ability or skill as a species. The gift of intelligence our large brains endowed us with gave us a huge advantage when it came to making hunting tools, such as spears and axes. And thankfully, we are not limited to using our tools and intelligence only at night, when we can’t see. We can also hunt during the daytime. Duh.
3. “Another ability hunting animals possess is the speed and ability to catch a wild animal with their bare hands.”
Recent researchers (e.g., Bernd Heinrich's Why We Run) have shown that humans, natural born endurance runners, can chase down a gazelle during the heat of the day, but you don’t have to believe that to understand the above claim is bullshit. Again, humans have big brains—and thus technology—so we don’t have to rely on our bare hands to hunt. We evolved axes, knives, spears and the bow-and-arrow to do things our hands can't. Moreover, with the ability to communicate and cooperate, we can hunt in groups, which makes much more formidable. All of these hunting abilities were quite remarkable, even by Paleolithic standards.
4. “A meat eaters intestines are very short, so that the fat content can be absorbed into its body. Humans have long intestines and must wait days to digest meat.”
Again, our intestines shrunk when we started eating seafood and meat. We do not have the same intestines as a chimp or gorilla. This is a fact.
5. “Excess fat absorption can lead to heart attacks and strokes.”
First of all, what kind of fat? There are many kinds: including monosaturated fats (MSF), saturated fats (SF) and polysaturated fats (PSF). MSFs, found in olive oil, nuts and avocados, have been proven to lower cholesterol and help prevent artery clogging. SFs, found in meats and dairy products, were standard fare for the 2.4 million years we gathered and hunted wild game, but then suddenly became “bad fats” in the 1950s when the late physiologist Ancel Keys and his now-infamous "Seven Countries Study" concluded that higher saturated fat consumption leads to increased levels of cholesterol and thus a greater occurrence of heart disease (aka "The Lipid Hypothesis"). However, as bestselling author and science journalist Gary Taubes so brilliantly outlined in his book Good Calories, Bad Calories, the data supporting Keys' claims was severely flawed and he made some rather misleading conclusions as a result.
Moreover, not all meat is equal. Meat from cows that have been fed grains—which are not part of their natural diet—has a low quantity of omega-3 fatty acids and a high amount of omega-6 fatty acids, which have been proven to cause inflammation. However, meat from grass-fed cows—or rather, cows allowed to feed on grass, the food they evolved to eat—is much healthier all around, containing a high amount of brain- and heart-friendly omega-3 fatty acids, and less inflammation-causing omega-6 fatty acids.
6. “Carnivores have special enzymes in their stomachs that kill the bacteria in rotting meat, and they love the way dead animals smell. Herbivores are without these enzymes and must find some other way to kill the bacteria, lest it kill them.”
Why would a human being want or need to eat rotting meat? A carnivorous scavenger might eat a rotting carcass; not a hunter. —Nor would he need to with all that fresh meat lying at his feet.
7. “Human culture may have evolved to eat meat, but your bodies have not.”
Oh, but they most certainly have. As I already mentioned, our big-ass brains simply would not have evolved had our ancestors avoided eating omega-3 fatty acid-rich meat and seafood. Chimps are not chimps because they lack a proper culture, they lack the proper brains.
8. “Eating meat is like smoking tobacco. Humans have done it for centuries and find it pleasurable, but in the end it can kill you.”
Although Ancel Keys would agree, there is a growing body of evidence that this statement is utter bullshit. If you like cheap yet convincing documentaries, see comedian (and chronic meat-eating) Tom Naughton's “Fat Head.” If you are of a more academic bent, read Taubes’ Good Calories, Bad Calories. Or, hell, hit 'em both up.
9. “If you want to find out if your own species is carnivorous, try this test: Give a baby an apple and a bunny. If it plays with the apple and eats the bunny, you’ve got a carnivore.”
Fail. First of all, babies don’t eat apples or bunnies. Certainly not whole. They drink mother’s milk—and should continue to do so at least until age two according to the World Health Organization. In most tribal cultures, babies are breastfed for at least three years. In any event, if you actually gave your darling infant daughter a whole apple—and I have—she will indefinitely play with it. Which she did. But along with breast milk, she does eat apples (mashed), along with a wide variety of fruits, vegetables and fish. She’s not picky. I imagine she’d eat rabbit too—although we haven't yet tried. As long as it wasn’t served whole and raw, that is.
Certainly a chimp wouldn't turn down a delicious plate of beer-braised wabbit, and perhaps you shouldn't either.
