2350 words

It is assumed that since the advent of agriculture that we’ve been better nourished than our hunter-gatherer ancestors. This assumption stems from the past 130 years since the advent of the Industrial Revolution and the increase in the quality of life of those who had the benefit of the Revolution. However, over a longer period of time, the advent of agriculture is linked to poorer health, vectors of disease and lower quality of life (in terms of intractable disease). Despite what I have claimed in the past about hunter-gatherer societies, they do have lower or nonexistent rates of the diseases that currently plague our first-world societies. Why do we have such extremely high rates of disease that they don’t?

Contrary to popular belief, agriculture has caused decreases in many facets of our lives. These diseases, more aptly termed ‘diseases of civilization‘ are directly caused by agricultural and societal ways of living. This increases disease rates as it’s easier for diseases to spread faster through bigger populations. Moreover, we haven’t had time to evolve to the current diet we now eat in first-world countries which has lead to what is termed an ‘evolutionary mismatch‘ between genes and environment. We evolved to eat a certain diet and the introduction of easily digestible carbohydrates which spike insulin the highest. Since insulin causes weight gain, and carbohydrate intake has dramatically increased since the 70s, obesity has increased as a result as countries begin to industrialize and more processed foods are available to the populace.

However, since the Industrial Revolution, height has increased along with IQ. Researchers argue that in first-world countries, high rates of obesity are not preventable due to the excess amounts of highly refined and processed foods. There is data for this theory. In first-world countries, the heritability of BMI is between .76 and .85. Since first-world countries are industrialized, we would expect them to hit their ‘genetic height and weight’ along with having the ability to reach their IQ potential. However, with the excess amount of highly processed and refined foods, this would also, in theory, have the population hit their ‘genetic weights’. This is what we see in first-world countries.

To see how first-world, industrialized societies cause these gene-environment mismatches, we can compare the disease acquisition rate—or lack thereof—to that of Europeans eating an industrialized, first-world diet (high in carbohydrates).

In his 2013 book The Story of the Human Body: Evolution, Health, and Disease, Paleoanthropologist Daniel Lieberman talks at length about evolutionary mismatches. The easiest way to think about this is to think about how one evolved to their environment and think how the processes that alter the environment. A perfect example is African farmers. They may dig a trench to divert water to better irrigate their crops, but this then would cause a higher rate of mosquitoes due to the increase in still water and then selection for genes that protect against malaria would be selected for. This is one example of an evolutionary mismatch turning into an advantage for a population. Most mismatch diseases are caused by changes in the environment which change how the body functions. In other words, the current first-world diet is correlated very highly with diseases of civilization and drive most of the mismatch diseases. Most likely, you will die from one of these mismatch diseases.

If you’re born in a hotter environment, you will have more sweat glands than if you were born in a cooler environment. If you grow up eating soft, processed food, your face will be smaller than if you ate harder foods. These are two ways in which ‘cultural evolution’ (cultural change) have an effect on how the human body grows and adapts to certain stimuli based on the environment around it.

The largest cause of the higher disease rate between industrialized peoples and those in hunter-gatherer societies is shifts in life history. As our life spans increased through modernization, so to did our chance of acquiring more diseases. Of course living longer affects how many children you have but it also raises your chances of acquiring an evolutionary mismatch and your chances of dying from one.

Daniel Lieberman writes on page 190 of his book The Story of the Human Body:

A typical hunter-gatherer adult female will manage to collect 2,000 calories a day and a male can hunt between 3,000 and 6,000 calories a day. (24) A hunter-gatherer groups combined efforts yield just enough food to feed small families. In contrast, a household of early Neolithic farmers from Europe using solely manual labor before the invention of the plow could produce an average if 12,800 calories per day over the course of a year, enough to feed families of six. (25) In other words, the first farmers could double their family size.

Thusly, you can see how evolutionary mismatches would occur with the advent of an agricultural diet that we didn’t evolve to be accustomed to. This is one of the biggest examples of the negative effects of agriculture, our inability to adapt quickly to our new diets which then accelerated after the Industrial Revolution. Further, hunter-gatherers will eat anything edible while agricultural societies will largely eat only what they grow. This would have huge implications for farmers if a few pests ruined their crops since they relied on a few crops to survive.

The thing about farming is that as the Agricultural Revolution began, this increased the population size as well as making that population pretty much stable in terms of migrating. This, then, led to higher rates of disease as larger populations foster new kinds of infectious diseases. Large populations didn’t happen until the advent of farming, and with it came the first plagues. The first farming villages were small, but “as the Reverend Malthus pointed out in 1798, even modest increases in a population’s birthrate will cause rapid increases in overall population size in just a few generations.” (Lieberman, 2013: 197) So as even small increases in population size would cause a boom in future generations, which along with it would drive disease acquisition and plagues in that new and stationary society.

Lieberman further writes on pages 199-200:

Not surprisingly, farming ushered in an era of epidemics, including tuberculosis, leprosy, syphilis, plague, smallpox and influenza. (44) This is not to say that hunter-gatherers did not get sick, but before farming, human societies primarily suffered from parasites such as lice, pinworms they acquired from contaminated food, and viruses or bacteria, such as herpes simplex, which they got from contact with mammals. (45) Diseases such as malaria and yaws (the nonvenereal precursor of syphilis) were probably also present among hunter-gatherers, but at much lower rates than in farmers. In fact, epidemics could not exist prior to the Neolithic because hunter-gatherer populations are below one person per square kilometer, which is below the threshold necessary for virulent diseases to spread. Smallpox, for example, is an ancient viral disease that humans apparently acquired from monkeys or rodents (the disease’s origins are unresolved) that was able to spread appreciably until the growth of large, dense settlements. (46)

Moreover, another evolutionary mismatch is the lack of sanitation that comes with stationary societies. Hunter-gatherers could just go and defecate in a bush, whereas with the advent of civilization, waste and refuse began to pile up in the area. As noted above, when farmers clear space for irrigation to plant crops, this introduces mosquitoes into the area which then causes more disease. Furthermore, we have also acquired about 50 diseases from living near animals (Lieberman, 2013: 201). There are more than 100 evolutionary mismatch diseases that agriculture has brought to humanity.

We can compare disease rates of people in industrialized societies and people in modern-day hunter-gatherer societies. In his 2008 book Good Calories, Bad Calories, Gary Taubes documents numerous instances of hunter-gatherer societies that have no to low rates of the same modern diseases that we have:

In 1914, Hoffman himself had surveyed physicians working for the Bureau of Indian Affairs. “Among some 63,000 Indians of all tribes,” he reported, “there occurred only 2 deaths from cancer as medically observed from the year 1914.” (Taubes, 2008: 92) “There are no known reasons why cancer should not occasionally occur among any race of people, even though it be below the lowest degree of savagery and barbarism,” Hoffman wrote. (Taubes, 2008: 92) “Granting the practical difficulties of determining with accuracy the causes of death among the non-civilized races, it is nevertheless a safe assumption that the large number of medical missionaries and other trained medical observers, living for years among native races throughout the world, would long ago have provided a substantial basis of fact regarding the frequency of malignant disease among the so-called “uncivilized” races, if cancer were met with among them to anything like the degree common to practically all civilized countries. Quite the contrary, the negative evidence is convincing that in the opinion of qualified medical observers cancer is exceptionally rare among the primitive peoples.” (Taubes, 2008: 92) These reports, often published in the British Medical Journal, The Lancet or local journals like the East African Medical Journal, would typically include the length of service the author had undergone among the natives, the size of the local native population served by the hospital in question, the size of the local European population, and the number of cancers involved in both. F.P. Fouch, for instance, district surgeon of the Orange Free State in South Africa, reported to the BMJ in 1923 that he had spent six years at a hospital that served fourteen thousand natives. “I never saw a single case of gastric or duodenal ulcer, colitis, appendicitis, or cancer in any form in a native, although these diseases were frequently seen among the white or European population.” (Taubes, 2008: 92) As a result of these modern processed foods, noted Hoffman, “far-reaching changes in bodily functioning and metabolism are introduced which, extending over many years, are the causes or conditions predisposing to the development of malignant new growths, and in part at least explain the observed increase in cancer death rate of practically all civilized and highly urbanized countries.” (Taubes, 2008: 96)

The preponderance of evidence shows that these people have low rates of disease that are endemic to our societies due to the advent of agriculture. There is one large difference between hunter-gatherer societies and industrialized ones: the type and amount of food we eat.

Along with the boom of agriculture, we see a slight decrease in height the longer people live in these types of societies. As the Neolithic began 11,500 years ago, height increased about 1.5 inches for males and slightly less for females. But around 7,500 years ago, stature began to decrease and we began noticing evidence of nutritional stress and skeletal markers of disease. There is evidence that as maize was introduced into eastern Tennessee about 1,000 years ago, a decrease of .87 inches in men and 2.4 inches in women were seen. Further, the height of early farmers in China and Japan decreased by 3.1 inches as rice farming progressed, with similar height decreases being seen in Mesoamerica in men (2.2 inches) and women (3.1 inches).

Anti-hereditarian Jared Diamond asks the question “Was farming worth it?” in which he writes:

With agriculture came the gross social and sexual inequality, the disease and despotism, that curse our existence.

The first two things he brings up are pretty Marxist in nature, though they are true. He implies that agriculture causes so-called ‘sexual inequalities’ in which women are made ‘beasts of burden’, made to do the work while men walk by ’empty handed’. This seems to be one negative to a society that is, supposedly, smarter than Europeans.

Regular readers may remember me criticizing Andrew Anglin and his stance on the paleo diet—with how it’s ‘how European man evolved to eat’. However, I am a data-driven person and I try to not let any bias get involved in my thought processes. I know do believe that we should eat a diet that closely mimics our hunter-gatherer ancestors, though we shouldn’t go overboard like certain people in the paleo community, we should be mindful of the quality of food we do it as we will greatly increase our life expectancy along with our quality of life. Indeed, researchers have proposed that we should adopt diets that are close in composition to what our hunter-gatherer ancestors ate in order to battle diseases of civilization. Based on what I’ve read over the past few months, I am inclined to agree. Indeed, evidence for this is seen in a sample of ten Australian Aborigines who were introduced back to their traditional lifestyle (O’Dea, 1984). In a 7 week period, they showed improvement in carbohydrate and lipid metabolism, effectively becoming diabetes-free in almost 2 months.

In sum, there were obviously both positive and negative effects on human life due to the advent of agriculture (leaning more towards negative). These range from diseases to increased population size, to ‘social inequalities’ to higher rates of obesity (this evolutionary mismatch will be extensively covered in the future) to a whole myriad of other diseases. These then lower the quality of life of the individual inflicted. However, the rates of these diseases are low to non-existent in hunter-gatherer societies due to them being nomadic and eating more plentiful foods. Agricultural societies become dependent on a few staple crops so when an endemic occurs, there is mass death since they do not know how to subsist on anything but what they have become accustomed to. The advent of agriculture leads to a decrease in stature as well as brain size. Further, agriculture and the processed foods that came with it caused us to become more susceptible to obesity, which was further exacerbated by the industrial revolutions and the ‘nutritional guidelines’ of the 60s and 70s that led to higher rates of coronary heart disease. It is the lifestyle change from agriculture that we have not adapted to yet that causes disease these diseases of civilization that shorten our life expectancies. I do now believe that all people should eat a diet as close to hunter-gatherer diet as possible, as that’s what the preponderance of evidence shows.

By the way, to my knowledge, contrary to what The Alternative Hypothesis says, there are no differences in carbohydrate metabolism between races (save for a few populations such as the Pima).