Sunday, September 22, 2013

The Food Crisis in Prehistory

For several million years — almost the entire human journey — our ancestors survived by hunting and gathering.  Until 10,000 years ago, everything on our menu was wild food.  By 2,000 years ago, most of our food came from farms, a rapid and radical change.  In his book The Food Crisis in Prehistory, archaeologist and anthropologist Mark Nathan Cohen explored two questions.  Why did we switch to agriculture?  Why did this shift occur, around the world, almost simultaneously?

His answer to both questions was population pressure.  Our preferred foods decreased as our numbers increased.  In the good old days, the preferred food for hunter-gatherers everywhere was large game.  It took far less time to kill a six-ton wooly mammoth than it took to kill six tons of rabbits, rats, or snails.  As long as large game was available, we were delighted to put the forks to them.

When large game became scarce, adventurous souls migrated into uninhabited regions, in search of nourishing four-legged banquets.  Because we were so clever with tool making, we learned how to survive in almost any type of ecosystem, wet or dry, roasting or frozen.  Eventually, we ran out of uninhabited regions, and large game became scarce everywhere.  Before long, less-preferred foods began to look like a delicious alternative to starvation.

When large game was our primary preferred food, the planet’s carrying capacity was maybe 15 million people, Cohen estimated.  He believed that the transition to agriculture had three phases: (1) large game, (2) small game, aquatic resources, more plant foods, and (3) domesticated foods.  The archaeological record in most regions generally supports this.

Climate change also played a role.  As the ice ages passed, the weather warmed up, and tundra ecosystems were replaced by forests.  Large tundra critters became hungry homeless ruffians, and many of them staggered toward the exit.  Forest critters like aurochs, deer, and pigs were not animals that lived in vast herds.  Hunting them required more effort.  By and by, we zipped past Peak Large Game.

Cohen found plenty of evidence that the trend throughout the long human journey had been one of population growth, slow but fairly steady.  Some societies did a good job of voluntarily limiting their numbers, and others didn’t.  Some surely lived in balance for multiple generations.  Joseph Birdsell estimated that during the Pleistocene, 15 to 50 percent of all live births were eliminated via infanticide.  Deliberate stability was better than growth-driven starvation, but stability was a slippery ideal.  In an ever-changing world, stability can only be temporary.

The notion of carrying capacity sets a firm limit on how many deer an ecosystem can support.  For humans, carrying capacity limits were more flexible, because we could digest a wide variety of plant and animal parts.  When rhinoceros steaks were no longer available, we began eating more plant foods, smaller game, marine mammals, salmon, shellfish, birds, seeds, nuts, snails, reptiles, insects, and so on.  It was more work, but it kept us fed, and our numbers slowly kept growing.

This transition from a Class A diet to a Class B diet occurred in all societies, in various forms, and it increased the carrying capacity for humans.  You can guess what happened next.  We eventually thumped against the ceiling once again, despite our new high-tech nets, bows and arrows, traps, weirs, fishhooks, harpoons, and so on.  What now?  Our options included die-off, bloody conflict, effective family planning, and/or a Class C diet.

Fate tossed the dice, and a crap diet won.  Agriculture was not a brilliant discovery.  A million years ago, everyone knew what happened when seeds were planted.  Everyone knew that tending plants was laborious.  In a world of abundant animal food, most plant foods were held in low regard.  “People worldwide eat meat and various fruits when they can, and eat cereals and tubers only when they must,” said Cohen.  A cereal-based diet had many nutritional drawbacks, and nothing was more excruciatingly dull than a diet that majors in hot porridge.

We routinely fail to appreciate the elegant time-proven culture of wild foragers.  They ate a wide variety of nutritious wild plants that evolution had fine-tuned to survive the various quirks of the local ecosystem.  Because they weren’t dependent for survival on just two or three domesticated plant foods, Bushmen could easily survive a three-year drought that hammered nearby ranchers.  Foragers were healthier people, because wild foods were more nutritious, and the nomadic lifestyle discouraged disease.

Farming was backbreaking work.  It required tilling, planting, weeding, and watering — months of effort invested before the payoff, if any.  The threats of drought, deluge, frost, insects, disease, fire, hail, and winds could zap a thriving crop at any time.  When the grain was ripe, there was a window of opportunity for harvesting it, which sometimes only lasted a few days.  If you missed it, you were doomed.  The stalks had to be cut and then threshed.  If the grains were not loose enough, some roasting was needed.

Storage pits or granaries had to be built, and constantly defended against assorted moochers and thugs.  Before storing it, the grain had to be parched to prevent germination, and to discourage molds and fungi.  Prior to cooking, grain had to be pulverized by pounding or grinding.  In the New World, living on maize required even more work.

Population pressure propelled the spread of agriculture to every suitable habitat.  Small societies of hunter-gatherers were helpless to oppose the growing onslaught of belligerent mobs of porridge fiends and bread heads.  In recent times, we’ve discovered how to use soil to convert petroleum into edible food-like substances.  Today we’ve munched our way deeply into the realm of Class D foods, loaded with highly refined carbs, oceans of empty calories.

We’ve succeeded in temporarily stretching our carrying capacity to 7 billion, but little stretch remains before the inevitable snapback.  Even ghastly Class D foods will slam into firm limits — Peak Cheap Energy, Peak Fertilizer, cropland destruction, desertification, and the certainty that industrial agriculture has an expiration date.  Somewhere down the road, climate change is likely to eliminate most or all forms of farming.  The unusually stable climate of the last 10,000 years is a freak.

Observing the human journey from Cohen’s mountaintop, we can see above the fog of myths, and the big picture comes into better focus.  Even the hunter-gatherer way of life, as it occurred, was not sustainable over the long run.  If we had remained in balance, agriculture and civilization would have never happened.  Human efforts at voluntarily limiting population have not been 100 percent effective, and this failure has been amplified by our skills at neutralizing the traditional man-eating predators that provided essential mob control.  A herd of seven billion is a time bomb.

On a misty morning, a group of chimps sits at the edge of the forest, gazing at us.  They are our closest relatives, and for millions of years they have not blundered into tool addiction, domestication, or population explosions.  Predators are always free to invite the less alert to lunch.  Wild chimps are still healthy, happy, and sustainable.  They wonder how we became so lost and confused.  It’s never pleasant to watch old friends self-destruct from devastating addictions.  What happened?  Was it necessary to trash the planet?  Please!  Get a grip!  We miss you!  Come home!

Humankind is suffocating in toxic myths.  Critical thinking is a powerful antidote, and it’s a vast, barely explored continent.  In the coming decades, one way or another, the lights will be going out on civilization, as we know it.  In the time remaining, it would be wise to bury as many of these myths as possible, so that they will not poison the minds of future generations, if any.  It’s time for learning, thinking, and remembering.  We have many dragons to slay before we can recover our long-lost treasure, a reality-based understanding of where we came from, and who we truly are.  Our greatest need is for healthy new visions.  It’s time to go home.

Cohen, Mark Nathan, The Food Crisis in Prehistory — Overpopulation and the Origins of Agriculture, Yale University Press, New Haven, 1977. 


Gail said...

That is one of the most sensible explanations for our current predicament I have ever come across, thank you! I will have to read that book.

Ann said...

Thanks for another great post...most interesting. I see that you write a great deal on may be interested in this BBC documentary.

What Is Sustainable said...

Ann, thank you! Consider yourself hugged! I shared it to Facebook with this comment:

Are you one of those folks who indulges in the popular hobby of eating food? I just watched a video about farming that brought tears to my eyes more than once. The cinematography is gorgeous, and, more importantly, the content is bullshit-free, and holds no punches. It's 48 minutes long, but my viewing fritzed out about half way through. I'm wary of having great faith in permaculture, and the notion of population reduction didn't appear before the video croaked. I'll be back to see the whole thing. This video is certainly close to the top of the most intelligent and important presentations I've seen on the internet. I strongly recommend it to all food hobbyists. Just GREAT!

What Is Sustainable said...

Gail, you might also look at Cohen's book Health and the Rise of Civilization.

Anonymous said...

Hi Rick,

do you think we will ever find out why our ancestors quit hunter and gathering? There are so many different responses to this question. most say climate change and the end of big mammals. Other say because humans moved to colder regions for hunting. That allowed to store food in caves. other say ...
What is your opinion?\

What Is Sustainable said...

Cohen did a thorough job of research, and his book is jammed with lots and lots of facts and details. I can’t argue with his conclusions. He says it was population pressure — they didn’t have enough food (i.e., too many mouths, too little foresight). Warming climate killed off many megafauna in what was formerly northern tundra. People kept developing new and improved hunting technology and strategies. Inadequate attention was paid to family planning, and to putting limits on hunting. Many hunting groups disappeared because other groups in the region took up farming. When farming arrives, the good old days are over.

Anonymous said...

Great description of the change from hunting megafauna to hunting and gathering microfauna and flora to cultivation. However, its easy to exaggerate how quickly and completely those transitions occurred. I suspect the evolution happened over long periods and there were continuing overlaps as megafauna disappeared at different rates in different locations, and even to this day some hunting (e.g. fishing) and gathering continues with our agricultural society.

Tom Wagner said...

Is it true that our planet cannot support 7 billion? We (Americans) throw away 1/3 of our food and even in India, where under-nutrition is endemic, 1/3 of the food is lost by poor storage and spoilage. That's not to say there are not limits, but have we really already over-shot the earth's food carrying capacity. Is a crash inevitable?

What Is Sustainable said...

Anonymous, I don’t think that the transition was rapid. After we departed from Africa, we gradually spread everywhere, hunting along the way, often confronting large animals that had no fear of us. They had not coevolved with humans, so they did not perceive us to be a threat. As we migrated through different types of ecosystems, we developed hunting technology suitable for optimizing the kill. Our arsenal gradually grew in sophistication. Once we reached the end of land uninhabited by our species, we were forced to adapt to new restrictions.

What Is Sustainable said...

Tom, I'll respond to your comment via the forum in our course. I want to give you some links, and it's much easier to post hyperlinks on the forum. On Blogger, I'd have to write HTML text.