Why the West Rules--For Now (19 page)

Archaeologists have argued for decades over why this happened, without much agreement. At the end of a magisterial recent review, for instance, the strongest generalization that Graeme Barker of Cambridge University felt he could make was that farmers replaced foragers “
in different ways
and at different rates and for different reasons, but in comparable circumstances of challenges to the world they knew.”

Figure 2.4. Going forth and multiplying, version one: the westward spread of domesticated plants from the Hilly Flanks to the Atlantic, 9000–4000
BCE

Yet although the process was messy—going on across millennia at the scale of entire continents, how could it not be?—we can make
quite a lot of sense of it if we remember that it was, at the end of the day, all about Earth’s movement up the Great Chain of Energy. Orbital change meant that Earth captured more of the sun’s electromagnetic energy; photosynthesis converted some of that larger share into chemical energy (that is, more plants); metabolism converted some of that larger stock of chemical energy into kinetic energy (that is, more animals); and farming allowed humans to extract vastly more energy from plants and other animals for their own use. Pests, predators, and parasites in turn sucked as much of this newfound energy out of farmers as they could, but there was still plenty left over.

Humans, like plants and other animals, found a major outlet for their extra energy in sexual reproduction. High birthrates meant that new villages could grow rapidly until every square inch of available land was being farmed, whereupon hunger and sickness rose until they canceled out fertility. Energy capture and energy consumption then reached a rough balance. Some villages stabilized like this, always hovering on the edge of misery; in others a few daring souls decided to start over. They might walk an hour to a vacant (perhaps less desirable) spot in the same valley or plain—or trudge hundreds of miles in search of green pastures they had heard about. They might even cross the seas. Many adventurers must have failed, the ragged, starving survivors crawling home with their tails between their legs. Others, though, triumphed. Population boomed until deaths caught up with births again or until colonies spun off colonies of their own.

Most farmers expanding into new territory found foragers already living there. It is tempting to imagine scenes like something out of old Western movies, with cattle raids, scalping, and shoot-outs (with both sides using bows and arrows), but the reality may have been less dramatic. Archaeological surveys suggest that the first farmers in each region tended to settle in different areas from the local foragers, almost certainly because the best farmland and the best foraging grounds rarely overlapped. At least at first, farmers and foragers may have largely ignored each other.

Eventually, of course, foraging did disappear. You will find few hunters or gatherers today prowling the manicured landscapes of Tuscany or Tokyo’s suburbs. Farming populations grew rapidly, needing only a few centuries to fill up the best land, until they had no option but to push into the (in their eyes) marginal territories of the foragers.

There are two main theories about what happened next. The first suggests that farmers basically destroyed the original affluent society. Disease might have played a part; rats, flocks, and permanent villages certainly made farmers less healthy than hunter-gatherers. We should not, though, imagine epidemics like those that carried off Native Americans in their millions after 1492. The farmers’ and foragers’ disease pools had been separated by just a few miles of forest, not uncrossable oceans, so they had not diverged very far.

Yet even without mass kill-offs, weight of numbers was decisive. If foragers decided to fight, as happened on so many colonial frontiers in modern times, they might destroy the odd farming village, but more colonists would just keep coming, swamping resistance. Alternatively, foragers might choose flight, but no matter how far they fell back, new farmers would eventually arrive, chopping down still more trees and breathing germs everywhere, until foragers ended up in the places farmers simply could not use, such as Siberia or the Sahara.

The second theory says none of these things happened, because the first farmers across most of the regions shown in
Figure 2.4
were not descendants of immigrants from the Hilly Flanks at all. They were local hunter-gatherers who settled down and became farmers themselves. Sahlins made farming sound deeply unattractive compared to the original affluent society, but in all likelihood foragers rarely faced a simple choice between two lifestyles. A farmer who left his plow and started walking would not cross a sharp line into foragers’ territory. Rather, he would come to villages where people farmed a little less intensively than he did (maybe hoeing their fields instead of plowing and manuring), then people who farmed less intensively still (maybe burning patches of forest, cultivating them until the weeds grew back, then moving on), and eventually people who relied entirely on hunting and gathering. Ideas, people, and microbes drifted back and forth across this broad contact zone.

When people realized that neighbors with more intensive practices were killing the wild plants and chasing off the animals that their own foraging lifestyles depended on, rather than attacking these vandals or running away they also had the option of joining the crowd and intensifying their own cultivation. Instead of picking farming over foraging, people probably only decided to spend a little less time gathering and a little more time gardening. Later they might have to decide
whether to start weeding, then plowing, then manuring, but this was—to repeat an image from the previous chapter—a series of baby steps rather than a once-and-for-all great leap from the original affluent society to backbreaking toil and chronic illness. On the whole, across hundreds of years and thousands of miles, those who intensified also multiplied; those who clung to their old ways dwindled. In the process, the agricultural “frontier” crept forward. No one chose hierarchy and working longer hours; women did not embrace arthritic toes; these things crept up on them.

No matter how many stone tools, burned seeds, or house foundations archaeologists dig up, they will never be able to prove either theory, but once again genetics has come (partly) to the rescue. In the 1970s Luca Cavalli-Sforza of Stanford University began a massive survey of European blood groups and nuclear DNA. His team found a consistent gradient of gene frequencies from southeast to northwest (
Figure 2.5
), which, they pointed out, mapped quite well onto the archaeological evidence for the spread of farming shown in
Figure 2.4
. Their conclusion: after migrants from western Asia brought farming to Europe, their descendants largely replaced the aboriginal foragers, pushing their remnants into the far north and west.

The archaeologist Colin Renfrew argued that linguistics also supported Cavalli-Sforza’s scenario: the first farmers, he suspected, not only replaced European genes with southwest Asian ones but also replaced Europe’s native languages with Indo-European ones from the Hilly Flanks, leaving just isolated pockets of older tongues such as Basque. The drama of dispossession that ended the original affluent society is inscribed in modern Europeans’ bodies and reenacted every time they open their mouths.

At first the new evidence only increased the scholarly arguments. Linguists immediately challenged Renfrew, arguing that modern European languages would differ much more from one another if they had really begun diverging from an ancestral tongue six or seven millennia ago, and in 1996 an Oxford team led by Bryan Sykes challenged Cavalli-Sforza on the genetics. Sykes looked at mitochondrial DNA rather than the nuclear DNA Cavalli-Sforza had studied, and instead of a southeast–northwest progression, like
Figure 2.5
, identified a pattern too messy to be represented easily on a map, finding six groups of genetic
lineages, only one of which could plausibly be linked to agricultural migrants from western Asia. Sykes suggested that the other five groups are much older, going back mostly to the original out-of-Africa peopling of Europe 25,000 to 50,000 years ago; all of which, he concluded, indicates that Europe’s first farmers were mainly aboriginal foragers who decided to settle down, rather than the descendants of immigrants from the Hilly Flanks.

Figure 2.5. A story written in blood: Luca Cavalli-Sforza’s interpretation of Europe’s genetic makeup, based on a massive sample of nuclear DNA. He concluded that this map, showing degrees of genetic similarity of modern populations to the hypothesized colonists from the Hilly Flanks, with 8 representing complete similarity and 1 the lowest level of correspondence (measuring the first principal component in his statistical manipulation of the results, accounting for 95 percent of the variation in the sample), showed that colonists descended from the Hilly Flanks spread agriculture across Europe. But many archaeologists and some geneticists disagree.

The Cavalli-Sforza and Sykes teams squared off fiercely in the pages of the
American Journal of Human Genetics
in 1997, but since then their positions have steadily converged. Cavalli-Sforza now calculates that
immigrant farmers from western Asia account for 26–28 percent of European DNA; Sykes puts the figure nearer 20 percent. To say that one of Europe’s first farmers descended from southwest Asian immigrants for every three or four who descended from natives is oversimplifying, but is not far wrong.

PREDESTINATION

Neither Cavalli-Sforza’s and Renfrew’s claims nor Sykes’s alternative—nor even the emerging compromise between them—would have made the students at Nanterre very happy, because all the theories treat the triumph of farming as inevitable. Competition, genetics and archaeology imply, has little to do with exams or teachers, because it has always been with us. Its logic means that things had to turn out more or less as they did.

But is this true? People, after all, have free will. Sloth, greed, and fear may be the motors of history, but each of us gets to choose among them. If three-quarters or more of Europe’s first farmers descended from aboriginal foragers, surely prehistoric Europeans could have stopped farming in its tracks if enough of them had decided against intensifying cultivation. So why did that not happen?

Sometimes it did. After sweeping from what is now Poland to the Paris Basin in a couple of hundred years before 5200
BCE
, the wave of agricultural advance ground to a halt (
Figure 2.4
). For a thousand years hardly any farmers invaded the last fifty or sixty miles separating them from the Baltic Sea and few Baltic foragers took up more intensive cultivation. Here foragers fought for their way of life. Along the farming/foraging fault line we find remarkable numbers of fortified settlements and skeletons of young men killed by blunt-instrument traumas on the front and left sides of their skulls—just what we would expect if they died fighting face-to-face with right-handed opponents using stone axes. Several mass graves may even be grisly relics of massacres.

We will never know what acts of heroism and savagery went on along the edge of the North European Plain seven thousand years ago, but geography and economics probably did as much as culture and violence to fix the farming/foraging frontier. Baltic foragers lived in a chilly Garden of Eden, where rich marine resources supported dense
populations in year-round villages. Archaeologists have unearthed great mounds of seashells, leftovers from feasts, which piled up around the hamlets. Nature’s bounty apparently allowed the foragers to have their cake (or shellfish) and eat it: there were enough foragers to stand up to farmers but not so many that they had to shift toward farming to feed themselves. At the same time, farmers found that the plants and animals that had originally been domesticated in the Hilly Flanks fared less well this far north.

We frankly do not know why farming did finally move north after 4200
BCE
. Some archaeologists emphasize push factors, proposing that farmers multiplied to the point that they steamrollered all opposition; others stress pull factors, proposing that a crisis within forager society opened the north to invasion. But however it ended, the Baltic exception seems to prove the rule that once farming appeared in the Hilly Flanks the original affluent society could not survive.