Tag Archives: farming

Green revolution

October 1967 – June 1971

The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.

Paul Ehrlich. The Population Bomb 1968

Ironically, it was just around the time that Ehrlich wrote this that production of rice and wheat in India, the Philippines, and other countries was booming thanks to the Green Revolution – more productive plant varieties that could take advantage of fertilizer and pesticide inputs. It’s true, as Malthus pointed out long ago, that exponential population growth can eat up any conceivable increase in agricultural output. But the Green Revolution bought the world some breathing space until birth rates began to come down. It probably also eased some of the paranoia about food supply that played a part in two world wars.

Whoever makes two ears of corn, or two blades of grass to grow where only one grew before, deserves better of mankind … than the whole race of politicians put together.

Jonathan Swift

Our first beer, a toast

7 kya. We tweeted about the first known alcoholic beverage, from China, on September 11. Today comes another landmark in the history of alcohol, with the first known evidence for beer brewing, from Iran (based on chemical tests of ancient pottery jars). You can find a popular discussion of beer archeology here.

It’s likely that alcohol production goes back earlier than either of these dates. It may even go back before the beginning of agriculture. It’s probably gone on long enough for populations with a long tradition of farming to acquire some genetic adaptations to the availability of alcohol.

People in traditional societies are not just concerned with subsistence – with earning their daily bread by the sweat of their brow. They often put a lot of work into non-subsistence production that raises their prestige. There’s a big literature in anthropology on “costly signaling” (related to conspicuous consumption; for example) concerned with this phenomenon. Archeologist Brian Hayden proposes that the origin of agriculture itself was motivated not so much by subsistence pressures, as by the desire to produce luxury foods for feasts. The potential for alcohol production in particular might have spurred the early domestication of grains.

In that convivial spirit, moving from the distant past to the far future – even to the end of the Universe – here is a toast to the brewmasters, from the last novel by science fiction writer Jack Vance:

The waiter departed to fill the orders. He presently returned with four tankards, deftly served them around the table, then withdrew.

Maloof took up his tankard. “For want of a better toast, I salute the ten thousand generations of brewmasters who, through their unflagging genius, have in effect made this moment possible!”

“A noble toast,” cried Wingo. “Allow me to add an epilogue. At the last moments of the universe, with eternal darkness converging from all sides, surely someone will arise and cry out: ‘Hold back the end for a final moment, while I pay tribute to the gallant brewmasters who have provided us a pathway of golden glory down the fading corridors of time!’ And then, is it not possible that a bright gap will appear in the dark, through which the brewmasters are allowed to proceed, to build a finer universe?”

“It is as reasonable as any other conjecture,” said Schwatzendale. “But now.” The four saluted each other, tilted their tankards, and drank deep draughts.

Jack Vance Lurulu p. 181

First farmers

8.5 kya. Farming is now spreading out of the Fertile Crescent. Farmers have crossed the Aegean, and appear in the Balkans and Greece. (They got to Cyprus more than a thousand years earlier.) Farmers have also begun spreading out of the Yellow River and Yangzi River valleys in China.

There’s an argument among philosophers of a utilitarian bent, started by Derek Parfit, over which is better: a world with just a few very happy people (more happiness per capita), or a world crowded with a multitude of people for whom life is just barely worth living (more total happiness)? (The choice of the latter has been dubbed the “Repugnant Conclusion.”) Whatever the philosophical merits of one possible world or another, there’s little doubt about which direction social evolution usually takes. “God favors the side with the largest battalions” (a saying often attributed to Napoleon, but actually predating him), and agricultural populations have mostly managed to replace hunter-gatherers, even though they are probably worse fed and sicker on average. The DNA evidence shows that in Mediterranean Europe it’s replacement we’re talking about, not just the spread of new technologies. Migrants originally from Anatolia pushed aside indigenous hunter-gatherers without much interbreeding.

For a while, a decade ago, it looked as if the spread of agriculture might also explain much of the distribution the world’s major language families. Peter Bellwood’s book First Farmers made this case. According to this theory, the first farmers in Europe were speakers of an early Indo-European language that eventually gave rise to most of the languages of Europe, as well as Iran and northern India. We’ll see in days to come on Logarithmic History that the story turns out to be more complicated.

Roots and grains, clans and kings

9 kya. Agriculture got started in the Near East by 10,000 years ago, yesterday on Logarithmic History. But a very different agricultural system may have begun around today’s date on the margins of Kuk Swamp in the highlands of New Guinea. This early date is controversial, but agriculture was clearly in place by around 6.5 kya.

The folks at Kuk Swamp were harvesting (and at some point cultivating) root and tree products: taro, yams, and bananas. We know relatively little about the early history of such crops, and their New World counterparts like manioc and sweet potatoes, since they don’t preserve as well as grains like wheat, rice, and corn/maize.

And there may be a more consequential difference between roots and tubers, and grains. Many root crops don’t keep well once they’re harvested. Better to leave them in the ground and harvest small amounts as needed. But grains have to be harvested all at once, and then stored. And there may be a further social implication to this: in the case of grains, concentrated stores make it easier for tax collectors to step in and appropriate a part of the product. Around the world, grain agriculture eventually ends up associated with complex stratified societies, with elites supported by rents and taxes extracted from a dependent peasantry. Places where root and tree crops were the basis of subsistence were less likely to develop political organization beyond the local level. Highland New Guinea winds up illustrating this, with productive agriculture and dense populations, but tribal-scale politics.

roots_vs_grains

The Andes, where the potato was first cultivated, and a succession of empires eventually flourished, may be the exception that proves the rule. At high altitudes, potatoes could be preserved by freeze drying.

Domesticated, I tell you

10.5 kya. Agriculture is about 50 million years old, if you count ants and their underground fungus gardens. But human agriculture seems to begin about 10.5 thousand years ago, in the Fertile Crescent in the Near East, with the domestication, in a short space of time, of barley, two varieties of wheat, sheep, goats, pigs, and cattle. (As we have seen, the domestication of dogs came earlier, maybe a lot earlier.)

domesticated

Agriculture is one of the greatest changes ever in the human condition, but whether it was a net improvement for the average person is questionable. There’s a lot of evidence that people were worse fed, and sicker, in a lot of places once they started farming. On the other hand, agriculture supports more people per acre than hunting and gathering, usually by several orders of magnitude, so population pressure is probably a big motive for experimenting with planting seeds.

But we are still left with an unsolved question. Why, after tens of thousands of years in which human beings showed little inclination to adopt farming, does it develop independently within a five thousand year span in half a dozen spots around the globe? I’ve run into anthropologists who think that it just took that long for populations to reach carrying capacity, but this shows no appreciation at all for the time scale of exponential population expansion. Any human population with room to grow can increase its numbers tens or hundreds of time on a time scale of less than a thousand years. So something other than population-below-carrying-capacity must have kept people from taking up farming for a long, long time. Two possibilities

1) The Ice Age climate wasn’t suited for farming. This explanation was proposed by Robert Boyd, Peter Richerson, and Robert Bettinger. We’ve already seen that Boyd and Richerson argued that the extreme climate swings of past glacial periods favored adaptation via cultural learning (rather than via individual learning or natural selection). These same swings ­– like the dramatic return to glacial condition in the Younger Dryas Cold Event – might have been too much to allow for prolonged settled life in one place, and attendant experiments with agriculture.

2) People weren’t genetically adapted to settled life. For example, living a settled life generally means more exposure to disease. It could have taken a long time for humans to evolve resistance to diseases of sedentism. Another possibility: natural selection might have affected behavior over this time. There’s an argument to be made that human beings are a self-domesticated species – that we have selected ourselves, as we have selected other animals, to be tamer, and less aggressive. You can see primatologist Richard Wrangham and anthropologist Robert Franciscus at a conference the year before last making this argument, and talking about morphological indicators of domestication. They mainly talk about the transition to Homo sapiens, but some of the same morphological changes occur in the transition from early to later Homo sapiens over the past several tens of thousands of years. It may only be in the last ten thousand years or so that many human populations grew tame enough to live in settled communities and take up agriculture. In both ants and humans, behavioral evolution toward increasing cooperation within the species may have been a precursor to the domestication of other species.

No knead bread

11 kya. The Younger Dryas Cold Event, last hurrah of the last glaciation, is over. In the Near East, people are once again settling down in villages, harvesting wild grain, and hunting. Tomorrow on Logarithmic History comes the first generally recognized human domestication of plants – wheat and barley specifically. So to commemorate, here’s a recipe – one of the most popular ever from the New York Times – for no-knead bread that you can make overnight (although early farmers may have favored porridge and flatbread.)

bread

Jared Diamond took a dour view of agriculture, calling it the “worst mistake in the history of the human race.” And fans of the paleo diet claim that you should try to eat like our ancestors did before the invention of farming. But there are counterarguments: Many hunter-gatherers ate more starch and sugar (in the form of honey) than paleo proponents assume. Also, human populations (at least populations of farmers) have evolved since the beginning of agriculture; many of us are no longer quite genetically adapted to a hunter-gatherer diet. Finally, feeding most of the planet on a meat-heavy paleo diet may be impossible.

In any case, studies from the They Institute (“They did this one study …”) show that bread won’t make you fat if you only eat bread you bake yourself. So indulge.

No-knead bread

Ingredients

  • 3 cups all-purpose or bread flour, more for dusting
  • ¼ teaspoon instant yeast
  • 1 ¼ teaspoons salt
  • Cornmeal or wheat bran as needed

Preparation

  1. In a large bowl combine flour, yeast and salt. Add 1 5/8 cups water, and stir until blended; dough will be shaggy and sticky. Cover bowl with plastic wrap. Let dough rest at least 12 hours, preferably about 18, at warm room temperature, about 70 degrees.
  2. Dough is ready when its surface is dotted with bubbles. Lightly flour a work surface and place dough on it; sprinkle it with a little more flour and fold it over on itself once or twice. Cover loosely with plastic wrap and let rest about 15 minutes.
  3. Using just enough flour to keep dough from sticking to work surface or to your fingers, gently and quickly shape dough into a ball. Generously coat a cotton towel (not terry cloth) with flour, wheat bran or cornmeal; put dough seam side down on towel and dust with more flour, bran or cornmeal. Cover with another cotton towel and let rise for about 2 hours. When it is ready, dough will be more than double in size and will not readily spring back when poked with a finger.
  4. At least a half-hour before dough is ready, heat oven to 450 degrees. Put a 6- to 8-quart heavy covered pot (cast iron, enamel, Pyrex or ceramic) in oven as it heats. When dough is ready, carefully remove pot from oven. Slide your hand under towel and turn dough over into pot, seam side up; it may look like a mess, but that is O.K. Shake pan once or twice if dough is unevenly distributed; it will straighten out as it bakes. Cover with lid and bake 30 minutes, then remove lid and bake another 15 to 30 minutes, until loaf is beautifully browned. Cool on a rack.

Natufians

14 kya. The last glacial phase looks like it’s coming to an end, and people in the Natufian culture of the Levant look like they’re gearing up to invent agriculture. They’ve settled in villages, and are harvesting and storing grain, but not yet sowing it. This turns out to be a false start though. In a thousand years or so the glaciers will come back for a final hurrah (the Younger Dryas event), and only after this will farming actually get going.

If you plug different frequencies of different genes from a bunch of populations into a computer and ask it to generate a tree where genetically similar populations share closer branches, you get something like this:

cavalli-sforza tree

This is from the pioneering synthesis of genetics by Cavali-Sforza and co-workers, back in 1994. This looks like a nice diagram of humans spreading out of Africa, maybe some taking a southern route (the Southeast Asian branch), and others a northern route (North Eurasian), and I used to teach it this way in anthropology classes. But as we look at ancient DNA, we’re finding that things are more complicated. Even 14,000 years ago, the structure of populations is different from what we’re used to today. We’ve already mentioned the Ancestral North Eurasians earlier, who just maybe could have spoken a language ancestral to Greenberg’s Eurasiatic family.

In the Near East, too, things were complicated. A paper out just this August shows that there were three very different hunting and gathering populations in Anatolia, Western Iran, and the Levant. Folks in Iran and the Levant were as genetically distinct as modern Europeans and Chinese! Either the Near East during this period had just been settled by migrants from widely separated places, or there had been strong barriers to gene flow in place for some time. Since then people in the area have mixed a lot.

Each of these populations of hunters and gatherers will give rise to its own set of farmers. The Natufians will contribute a lot to the ancestry of later farmers in the Levant. And apparently each set of farmers will send migrants off in a different direction: the Anatolians to Europe, the Iranians (or some Caucasian relatives) to the Eurasian steppe, and the Levantines to East Africa. It’s possible that the Natufians were speakers of a language ancestral to the Afro-Asiatic family, one of the oldest widely accepted language families, including Arabic and Hebrew, Somali and Oromo.

And here’s Razib Khan on our new understanding of how different ancient population structure was.