Hunter-Gatherers -- Eric R. Pianka

Return to a Hunter-Gatherer Existence

Eric R. Pianka

At the end of the Pleistocene, just 10,000 years ago, only about 500 generations before now, humans were hunter/gatherers, living off the land in small bands or tribes. We had no electricity, no cars, and no supermarkets, let alone fast food joints. We did not live in houses, but found refuge in caves and crude shelters. We hunted animals with spears, bows and arrows, and nooses. We caught fish with crude nets and fish hooks made from sharp pieces of bone. We gathered nuts and berries. We used sinew as twine and made our own ropes. We had no jeans or shirts, underwear, or toilet paper -- we clothed ourselves in animal skins and furs, and wiped ourselves with leaves. We had no television but sat around campfires telling one another stories and passing on vital information from one generation to the next (this was the origin of human knowledge).

Our ancestors were pretty tough, surviving several prolonged ice ages that lasted for millions of years. They discovered fire and spent time huddled together in caves.


Survival through a winter, let alone an ice age, in the temperate zones was no easy feat under such conditions, requiring substantial advanced preparation and food storage, as well as no small amount of good luck. Certain human behaviors critical to survival became hard wired during this period. Some such human instincts include our fear of snakes, greed, revenge, as well as our urge to procreate, all of which were adaptive when there were many fewer of us and we lived in small bands. However, many of our instinctive behaviors have become maladaptive in today's overcrowded world (human nature).

Tribes probably defended territories against other small bands of humans, but must have occasionally exchanged members. Our primitive hunter/gatherer ancestors must have enjoyed a good life during times of plenty in spring and summer when food supplies were bountiful. There was limited "ownership" of such resources, and people could help themselves to whatever they could find. Money had not yet been invented and food was essentially free for the taking. Many fewer humans dwelled on Earth then, and the planet could easily supply their needs.

Paleopathology is the study of signs of disease in the remains of ancient peoples. A skeleton reveals its owner's age, sex, and weight. A population of skeletons can be used to construct mortality tables and to estimate expected life span and risk of death at any given age. Growth rates can be estimated by measuring bones of people of different ages, and teeth can be examined for enamel defects (signs of malnutrition). Scars left on bones reveal injuries as well as various diseases.

The average height of hunger-gatherers at the end of the ice ages was 5' 9" for men and 5' 5" for women. Following the adoption of agriculture, heights crashed, and by 3000 B. C. statures had reached a low of only 5' 3" for men and 5' for women.

A detailed study of 800 American Indian skeletons from burial mounds in Illinois and Ohio river valleys illustrate health changes that occurred around A. D. 1150 when a hunter-gatherer culture gave way to intensive maize farming (Diamond, 1987). Compared to hunter-gatherers who preceded them, farmers had nearly twice as many enamel defects indicative of malnutrition, four times as much iron-deficiency anemia (evidenced by a bone condition), a threefold rise in bone lesions reflecting infectious disease, and an increase in spinal degenerative conditions, a reflection of hard physical labor. Life expectancy at birth decreased from 26 years to only 19 years.

Agriculture was bad for health for several reasons. Hunter-gatherers enjoyed a more varied diet than early farmers, whose foods consisted of a few starchy crops. Farmers obtained cheap calories, but at the cost of poor nutrition. (Three carbohydrate rich plants -- wheat, rice, and corn -- provide the bulk of the calories consumed by humans today, yet each is deficient in certain essential amino acids or vitamins.) Due to their dependence on a limited number of different crops, farmers ran the risk of starvation if one crop failed. Because agriculture encouraged people to clump together in crowded societies, which then traded with other crowded societies, parasites and infectious diseases spread.

Agriculture also led to cities -- the invention of money allowed the wealthy elite to control poorer people and to live better. Runaway greed fostered inequality as the rich grew richer at the expense of the poor. Women were exploited as baby bearers and beasts of burden. Agriculture has thus cursed us with disease, despotism, economic depressions, revolutions, social and sexual inequality, starvation, tyranny, and warfare (Diamond, 1987).

Things are very different today -- demand for limited resources now greatly exceeds supply, and virtually everything is claimed as "owned" by someone else. As their populations burgeoned, humans invented agriculture and then money, and made the transition from being cave men and women to modern civilized urbanites quite rapidly. Many of our behaviors and instincts, once suitable for a caveman's existence, such as greed and revenge, became anachronous, even dangerous, and now threaten our very survival (instincts).

Our primitive hunter/gatherer ancestors had to have been good naturalists, and they must have been acutely aware that other life forms were critical to their very existence. We rely on other organisms for food, medicine, shelter, and clothing. Simply put, humans could not exist without our symbiotic bacteria, let alone without the endosymbiotic photosynthetic chloroplasts housed by all green plants. Indeed, many other life forms live on or in us (eyebrow mites). Many of the genes that drive our physiology and metabolic processes were invented billions of years ago by microbes in Earth's primeval oceans. Even your own blood plasma reflects our ancient origin: it is very close to sea water. We are but one small branch on the tree of life. We share most of our genes with other organisms, including bacteria and fungi.

Humans explain events and phenomena in two very different ways. One approach to knowing (sense 1, common sense) involves thinking and is objective, based on making repeatable observations that allow us to predict nature and future events -- this rational logical approach to knowing led to scientific methodology. Another, very different, non-objective mystical approach to 'knowing' (sense 2, faith-based) is based primarily upon the invocation of 'super'natural explanations, bolstered by authorities who claim to have special access to 'super'natural sources. This non-scientific approach, championed by religions of all kinds, has helped many humans accept and cope with things they have no power to change or difficulty understanding rationally, such as unexpected deaths, other misfortunes, or natural disasters. Unfortunately, the power conferred on religious leaders has often led to serious abuses and resistance to accepting the rational understanding of the functioning of nature as demonstrated by new scientific discoveries. These two diametrically opposed ways we interpret and 'know' (sense 1 versus sense 2) about our environments have contributed to the regrettable past and modern day conflicts between science and religion.

Human intelligence has also evolved so that we have remarkably good abilities to detect intentions of other humans in social interactions. We seem to have a propensity for mysticism and a tendency to emphasize explanations that invoke intention over those based on sheer mechanism, situation, or circumstances. Indeed, humans may be predisposed to see intentions in their friends and enemies. Similarly, they attribute conscious thought and intention to the actions of non-human animals (anthropomorphism). For example, predators 'want' to kill us and prey 'want' to escape from us. We even look for meaning and purpose in inanimate things such as the climate or the universe. Thus a destructive storm is interpreted as having occurred because people strayed from religious tradition or did something wrong and had to be 'punished.'

Everyone, religious or not, relies on objective rational thinking to handle problems encountered in everyday life. Thus, we all know we must eat to stay alive, things fall down not up or sideways, we seek to avoid collisions when driving, balance our budgets, etc. Remarkably, many people switch back and forth between rational knowing (sense 1) to faith-based 'knowing' (sense 2) with ease. Our brains may be organized in ways that promote such duality (download Morrison's "Evolution's Problem Gamblers").

Adamant insistence on faith-based 'knowing' coupled with careless use of words like 'believe' and 'truth' have provided numerous opportunities to foment confusion and have allowed science to be deliberately maligned and misrepresented by those who stand to lose from changing sensibilities. Thus, religious leaders have often rejected new scientific evidence because it reduced the domain of processes over which religion could claim authority. As a result, scientific investigators have sometimes been vilified as Galileo was during the Spanish Inquisition -- scientists have even been tortured and executed because their views conflicted with mystical belief systems.

Accurate knowledge of basic principles of community organization and ecosystem function are essential for wise exploitation of both natural and agricultural ecological systems. An understanding of basic parasitology is needed to control epidemics in human populations. The continuing existence of all the denizens of this poor beleaguered planet, including ourselves, will ultimately depend more on our ecological understanding and wisdom than it will on mysticism or future technological "advances." We cannot rely too much on technological solutions. Technology is what got us to this precarious situation in the first place. Rather, we must reorganize society and change our own lifestyles. Unless everybody plays his/her part, we are doomed.

We must convert to a sustainable system where each of us leaves the planet in the same condition that it was in before we were born. This will require many fewer of us and much less extravagant lifestyles. We won't be able to move around so freely (airplanes will become a thing of the past) and we will have to go back to walking and riding horses. In addition, humans will have to be more spread out, living without big cities. Before it is all over, we are going to have to limit our own reproduction, un-invent money, control human greed, revert back to trade and barter, and grow our own crops, among other things (Human Instincts).

In progress, last updated 13 June 2014 by Eric R. Pianka