ARCHAEOLOGY: Uncovering Civilization's Roots

[Zeno Swijtink]

Science 17 February 2012:
Vol. 335 no. 6070 pp. 790-793
DOI: 10.1126/science.335.6070.790

• ARCHAEOLOGY

Uncovering Civilization's Roots
Andrew Lawler


What sparked the first cities? Digs in Kuwait and Syria are reshaping how archaeologists see the first stirrings of urban life.

It takes a village.

Warsaw's Andrzej Reiche surveys an ancient Ubaid workshop in Kuwait, home to a new way of life that eventually led to urban civilization.

CREDIT: AHAN KALPA KHALSA

BAHRA, KUWAIT—Camels are picking at scrub in the desert here, while archaeologist Piotr Bielinski puzzles over the jumbled remains of a 7000-year-old village in this desolate spot. Although the skyscrapers of Kuwait City form a distant backdrop 40 kilometers away, today there is little here to draw people. This site is a long walk to the Persian Gulf, has no obvious water source, and seems to lack valuable resources. In summer, the surrounding desert is a furnace, while bitter winter winds blow unimpeded from neighboring Iraq. But long ago, some 100 people created a tidy and prosperous settlement here, and the remains of their village may provide clues to the subsequent emergence of the world's first cities.

Why settle here? The riddle confronting University of Warsaw scientist Bielinski is part of an ambitious attempt to explain how humans made the momentous leap from village life to urban sprawl. That transformation first happened in Mesopotamia sometime during the 4th millennium B.C.E. in what archaeologists call the Uruk phase, named after a southern Iraq metropolis some 300 kilometers north of Bahra. But recent excavations in Kuwait, Syria, Iran, and Saudi Arabia provide mounting evidence that the origin of the urban revolution is to be found in the prior era, called the Ubaid, which began around 5500 B.C.E and lasted until about 4000 B.C.E. (see timeline, p. 792). Piecing together how and where that mysterious culture began, spread, and evolved “is a particularly hot topic right now,” says Harvard University archaeologist Jason Ur. Adds University of Chicago archaeologist Gil Stein: “This is the earliest complex society in the world. If you want to understand the roots of the urban revolution, you have to look at the Ubaid.”

At Bahra, archaeologists have found the oldest permanent settlement south of Mesopotamia. The finds come on the heels of a joint U.S.-Syrian discovery of a surprisingly large and sophisticated Ubaid town on the northern fringe of the Mesopotamian plain. Data from both sites contradict the old assumption that Ubaid culture was spread by precocious southern Mesopotamians who colonized their more primitive neighbors—a harbinger of the militaristic Mesopotamian empires to come. Instead, these and a handful of other sites suggest that a loose network of local peoples from the Mediterranean Sea to the Persian Gulf helped shape a way of life that eventually spawned cities.

Some archaeologists argue that crop irrigation and the resulting food surplus spurred that rise, while others cite the appearance of kings, colonial domination, or spread of a common religion. But the new Ubaid finds add weight to the hypothesis that growing contact among different groups—a so-called interaction sphere—was the spark that eventually ignited the urban revolution. “There is a direct correlation between an increase in cultural interaction and an increase in cultural complexity,” says Harvard archaeologist Carl Lamberg-Karlovsky.

Although researchers agree that factors such as irrigation and trade were key to seeding civilization, the emphasis has shifted to how those ideas grew and spread. The new data suggest that the Ubaid was a time of mutual exchange among independent peoples rather than control asserted by a single sophisticated group. “Like the Ottoman Empire, people may have adapted in different ways,” Bielinski says, his face ruddy from the sun and wind. Stein, who leads the dig in Syria, uses another analogy: “It's almost like the European Union,” he says. People shared a common identity but retained their own local traditions. That view puts a radically different spin on civilization's emergence.

Deep digging

Sumer—Shinar in the Hebrew Bible—is the name of ancient southern Mesopotamia, where archaeologists discovered the first cities a century ago. One of the oldest and largest was Uruk, which expanded sometime around 4000 B.C.E. and by 3100 B.C.E. covered more than 100 hectares, boasting massive temples, a city wall, the first administrative writing system, and tens of thousands of people. Uruk pottery and trade goods from this time turn up across a wide area of the Middle East.

In the 20th century, archaeologists digging in southern Iraq began to get glimpses of pottery and buildings from an even older era, which they dubbed Ubaid after the ancient town on the southern Mesopotamian plain (see map) where it was first identified. But Ubaid remains were often buried under later cities or thick deposits of silt, Stein says. At Tell Ouelli, for example, French archaeologists dug 4.5 meters to reach Ubaid material. They found surprisingly spacious buildings but had to stop when they encountered the water table. At Eridu, which the Sumerians themselves considered the world's oldest city, excavators peeled back an extraordinary series of increasingly large and elaborate temples, which for 3000 years were built on top of what began as a modest early Ubaid structure.

The continuity of architecture from the Ubaid to Uruk is striking. Older settlements exist, such as Jericho on Palestine's West Bank or Çatalhöyük in Turkey (Science, 29 October 1999, p. 890). But only Ubaid sites underlie the first cities. Although the sites are relatively small and lack complex organization, the people of this era were among the first in the world to spin wool into cloth, use the wheel to manufacture distinctive pottery, irrigate their fields, and live in well-planned rectangular houses with multiple rooms. Overall, the Ubaid seems egalitarian, like previous Neolithic cultures, but archaeologists have spotted hints of social stratification. A few infant graves had many goods, and one home at Tell Abada, east of Baghdad, was several times the size of the town's smallest dwelling. That mansion was maintained for nearly 2 centuries, demonstrating not just a difference in wealth but also an ability to pass on wealth and status to succeeding generations, Stein notes.

Telltale signs of Ubaid life, such as skulls shaped in infancy by banding, have turned up in a 2000-kilometer swath from Turkey to Iran. Ubaid potsherds with bold patterns that sometimes include stylized images of dancers and animals have been found as far southeast as the Persian Gulf shore of Oman and as far northwest as the Mediterranean coast. That footprint is as large as the reach of the Uruk city-state in the 4th millennium B.C.E. “It is the first time you see the spread of material culture across so wide an area,” says University of Cambridge archaeologist Joan Oates, a pioneer in Ubaid studies.

Although the plains of southern Mesopotamia have rich soil, they lack timber, stone, metals, and other natural resources. So scholars once assumed that what they termed the Ubaid expansion was the result of southern Mesopotamian traders, colonists, or even warriors moving into other lands to gather needed resources. But discoveries of Ubaid villages and towns across northern Mesopotamia—some of which were founded even before the Ubaid began and grew larger in the 5th millennium B.C.E.—suggest indigenous development. “We can't assume [the Ubaid expansion] is the spread of people,” Oates says.

Stein's dig at Tell Zeidan in northern Syria provides the latest and most definitive evidence that the Ubaid culture was more complex than once thought and that it was not simply the product of southern Mesopotamian migration. Located at the juncture of two trade routes, Tell Zeidan is made up of three large mounds covering more than a dozen hectares—at least as large as Eridu in the 5th millennium B.C.E.—and with as many as 3000 inhabitants. Elaborate stamp seals used to mark goods or rooms reveal that some people were controlling goods or access—a sign of early administrative complexity and possibly the start of a hierarchy. Smelters processed copper while craftsmen shaped obsidian into cutting tools; both kinds of raw materials came from 400 kilometers away in Anatolia. To make flint sickles for harvesting grain from their irrigated fields, the people of Tell Zeidan used bitumen from Iraq.

At another site to the north of Tell Zeidan, in today's Turkey, people built Ubaid-style houses clustered closely together as they had their Neolithic huts. That contrasts with the south, where houses were set apart from one another. Such finds, which now include sites in Iran as well, suggest that this was not a monolithic culture. “TheUbaid is actually many Ubaids that developed in tandem at roughly comparable rates,” says archaeologist Guillermo Algaze of the University of California, San Diego. He envisions several independent polities exchanging goods and ideas and possibly competing with one another. He adds that the Ubaid marks “a notable advance of social complexity” across a broad area called Greater Mesopotamia.

Down south

By contrast with Mesopotamia, the sparsely settled Persian Gulf region has until recently attracted little attention from archaeologists. A scattering of Ubaid potsherds have turned up on the Arabian side of the gulf, but they were thought to have been left by occasional Mesopotamian traders.

Then a decade ago, a team co-led by archaeologist Robert Carter, now of University College London's campus at Doha, Qatar, excavated a substantial Ubaid encampment on the Kuwaiti coast. The team found remains of the oldest seafaring boat, complete with barnacles, as well as the oldest pierced pearl. Then in 2007, a Kuwaiti researcher turned up Ubaid potsherds 7 kilometers inland. Bielinski and his team have now excavated a stone-ringed burial chamber with more than 600 Ubaidtype beads and ornaments of shell, stone, and mother-of-pearl—an unusually large quantity and quality for this barren region. And during the past three seasons, excavators dug a 200-meter by 50-meter area revealing a series of six to eight rectangular buildings strongly reminiscent of Ubaid architecture amid a scatter of Ubaid pottery as well as a cruder red ware.

The most remarkable find was a large room with a paved stone floor and a stone podium in the middle. “At first we thought the podium might be an altar in a temple,” recalls archaeologist Andrzej Reiche of Warsaw's National Museum. But given the plethora of beads and shells, “it appears this was a table in a workshop.” The room contained shell beads in different states of production along with flint drills. The scale suggests to Reiche that settlers here made beads for export.

Although Bahra today is high and dry, in its heyday it was between 1 and 3 kilometers from the gulf, says archaeologist Jennifer Pournelle of the University of South Carolina in Columbia, and fresh water was likely nearby. Carter adds that Bahra appears roughly contemporaneous or slightly later than his nearby coastal site, which may have been a seasonal camp or trading center. “I would guess it was very closely related, or the same community,” he adds.

The identity of Bahra's inhabitants, however, remains in dispute. Oates thinks they were Mesopotamians seeking fish, pearls, and other resources. She adds that the settlers likely brought their own fine serving ware but made the crude red clay pots for cooking. Bielinski, however, suspects that the Bahra people were locals participating in the wider Ubaid culture. He notes the use of parallel stone slab construction, a method that works well for oval-shaped houses typical of Neolithic Arabia but makes less sense for the rectangular structures of Mesopotamia. The structures, he concludes, likely were not built by experienced Mesopotamian masons but by locals seeking to emulate the fashion. As for the red ware, “it's as if the local people saw the Ubaid pottery and said, ‘That's a good idea,’” Stein says.

Also, the few flints thus far found come from poor-quality sources in southern Kuwait rather than from higher-quality northern sources accessible to Mesopotamians. Bielinski cautions that it's too early to fully understand the settlement. Still, he says, “in front of an American jury I can't defend it, but this wasn't built by people from the north.”

Paving the way

Whoever the Bahra people were, both the Syrian and Kuwait finds, as well as recent discoveries of Ubaid material in Turkey, Saudi Arabia, and Iran, point to a slow but extensive transmission and sharing of goods, ideas, and technologies during this time. The twin sites in Kuwait, Carter says, nicely illustrate “this early spurt of globalization.”

By 4000 B.C.E., Ubaid pottery and other materials vanish from the record across Greater Mesopotamia. But within a century or two, the protocities of Uruk in the south and Tell Brak in the north were expanding (Science, 9 June 2006, p. 1460). These formidable settlements had more than burgeoning populations: They controlled surrounding areas, employed administrators and craft specialists, and bore the hallmarks of central organization. Within 500 years, Uruk trade and fashions dominated an area comparable to that of the Ubaid, while other cities began to emerge elsewhere in Mesopotamia.

Ultimately, archaeologists say, the Ubaid's most important innovations were not technological but social. A new style of housing, blossoming trade, specialty jobs, temples, and growing acceptance of a budding social hierarchy changed the way people saw themselves and related to others, Bielinski says. Practical acceptance of outside ways rather than “slavish imitation” was the Ubaid way, Stein adds.

And southern Mesopotamia was not the source of the entire culture. At least one form of pottery, a greenish buff ware with black paint, seems to appear in northern Mesopotamia first. Iranian digs have revealed some of the earliest examples of banding infant skulls. The popularity of wool provided new markets for a growing number of pastoralists, who may have played a key role in transmitting goods and ideas.

In this emerging picture, the Ubaid is a dress rehearsal for the radical changes to come. Across an area of unprecedented size, a complicated mix of peoples experimented with what became the building blocks of civilization. “There were tremendous integrative forces coming into play at this time,” Carter says. Despite the similarity of pots and architecture from Turkey to Oman, “it was not a homogenous cultural landscape.” What began to emerge, Harvard's Lamberg-Karlovsky says, were the “technologies of social control,” such as writing and organized groups of laborers that ultimately created our modern complex society.

But further exploration of the deeply buried Ubaid sites in Iraq will not be easy. Sectarian turmoil in Syria has halted the excavations at Tell Zeidan, preventing Stein's access to what he calls “archaeological heaven.” And Iran remains off-limits to foreigners. Such constraints suggest that the Ubaid peoples will retain some of their ancient mystery for years to come.