The Echoes of Ancient Humans

Artifacts from Israel suggest that people developed language and other key abilities early in their evolution

By HAIM WATZMAN

Gesher Benot Ya'aqov, Israel

Naama Goren-Inbar kneels at the water's edge, the sinewy fingers of her right hand picking through the mud for bones and flint chips. Three bare-chested young men float lazily down the narrow channel of the upper Jordan River, laughing boisterously as they sprawl over a pair of overturned inflatable kayaks. Just to the north, twin Bailey bridges clatter like steel roller coasters with each passing car, making it hard to hear Ms. Goren-Inbar as she vents her frustration.

"Wouldn't you know it. Now that we're here, I can't find a single bone."

She need not worry. In seven excavation seasons at this spot, Ms. Goren-Inbar, an archaeologist from the Hebrew University of Jerusalem, exhumed so many artifacts of prehistoric humankind that she will be busy analyzing them for years to come.

The archaeological jackpot is on a patch of riverbank here, seven miles north of the Sea of Galilee, where layered sheets of rock jut out of the ground and the river at odd angles. Wedged between the Jordan and an old Syrian minefield, it is no larger than a bedroom. That's all there is to the site, known in Hebrew as Gesher Benot Ya'aqov (Daughters of Jacob Bridge) — GBY, for short. The material that Ms. Goren-Inbar has found there provides a picture of our ancient human ancestors that differs from the one accepted by most scholars. The tools and trash left here demonstrate, Ms. Goren-Inbar maintains, that the women and men who lived on this spot more than 780,000 years ago were far more advanced than scholars have previously thought. Those ancient people were able to cogitate, strategize, and converse with each other — in short, to engage in many of the behaviors that help to define our species.

"These people were very sophisticated," she says. "Everyone thinks Stone Age men were like this," she says, demonstrating by curling her hands into claws, hunching her back, furrowing her brow, and thrusting out her lower jaw — a pose that draws glances from the rafters. "But they had brains as big as we do."

Her claims have ignited an intense debate among scholars who study prehistoric humans. The only archaeological artifact that can provide solid evidence about the thought processes and language of ancient peoples is writing — which was invented only about 6,000 years ago. Absent that, the discussion centers on the interpretation of the rocks, bones, flora, and fauna left behind by early men and women.

Some of this kind of evidence was literally littering the ground when Ms. Goren-Inbar first came to the GBY site, in the 1980s. She found the surface strewn with unusual stones that had clearly been altered or worked by early humans, who banged together rocks to produce sharp-edged tools. At archaeological sites, those tools come in various styles, or "industries," which seem to hold constant over large areas and for long periods of time before innovations lead to the creation of a new style.

The stone tools at GBY are distinctive in that they have been banged on two sides to create sharp edges. What's more, most of those in the oldest strata were made not of flint, which was favored in later periods for tools, but of basalt. Those features gave Ms. Goren-Inbar clues about what kind of people were living in the Near East at the time.

Shopping for Stone

The Jordan River Valley was a highway of sorts then, a route that early humans took as they left Africa. As they walked, they took their technology with them. The same kind of double-sided basalt tools found here on the Jordan are also prominent at sites in East Africa. The culture that produced these tools is called Acheulean.

The earliest Acheulean finds in Africa date to about 1.6 million years ago. The earliest ones in the Jordan Valley — at Ubeidiya, just south of the Sea of Galilee — date to 1.4 million years ago. In geological terms, that amounts to an instant. It means that the Acheuleans radiated out of Africa and through the Jordan Valley almost as soon as they appeared.

"What's fascinating about Gesher Benot Ya'aqov is that we find them using the local basalt rock with classically African techniques to make hand axes and cleavers," says Derek Roe, an archaeologist from the University of Oxford, who specializes in early human sites, in a telephone interview. "In Africa basalt lies in large blocks all over the landscape. In the north, that kind of rock is scarcer, yet at this site we see the same technology being used right on the route out of Africa."

Although the people of Gesher Benot Ya'aqov could have reached out and touched the basalt boulders of the Golan Heights, that nearby rock is weak and porous. They had to go far afield to find the dense, high-quality basalt they needed for tools.

"That means they had to map the formations, schlep tools, search for raw materials," says Ms. Goren-Inbar, who has been directing excavations since 1979.

Short, dark and intense, she jumps from desk to whiteboard to bookshelf in her office, pointing out fossils and tools from different parts of the world. "They had to know where to go, how to cut it out of the large block of stone, and where to bring it to for further processing," she says of the Acheuleans. And the consistency of the tools over the long periods of time represented by the strata, she continues, indicates that they were teaching their children these skills.

"These early hunter-gatherers had big brains and mental abilities that seem to be much higher than that of their predecessors," she says.

Evidence From an Elephant

Ms. Goren-Inbar thinks that some of the tools at GBY were used for hunting and dismembering large game. At that time, 780 millennia ago, the Jordan Valley was a lush, relatively warm corridor linking Africa with Asia. Large mammals roamed the area. The plentiful water and food there made the valley an attractive pathway for the humans who colonized Eurasia.

In 1989 she and her colleagues unearthed the overturned skull of an elephant near the bridges. Under the skull was one end of a long, thick, oak log. Close by was a basalt core, a large rock cut to form a sharp working edge. Judging from the placement of the artifacts and other archaeological and anthropological evidence, the archaeologists suggested that humans had killed the elephant, used the log to overturn its skull, and cracked open the skull with the basalt core. That provided access to the brain, a prized cut of meat.

A paper that she and three colleagues published in 1994 argues that hunting and dismembering a large animal require a high level of planning and coordination. Ms. Goren-Inbar says she can't imagine humans conducting such a complicated procedure without the efficient sort of communication that only language can provide.

Most recently, she and her colleagues argued in a paper published in Science in 2004 that the earliest humans at Gesher Benot Ya'aqov used and controlled fire. Other archaeologists have claimed evidence of human use of fire at sites that predate GBY. But that evidence is ambiguous, and some argue that the soot and charred material at those sites could just as well be the result of a lightning strike or some other natural cause.

At the Jordan River site, Ms. Goren-Inbar and her colleagues sifted through the gravel they had unearthed to extract tiny pieces of burned stone, wood, and seeds — some only two millimeters long. When they mapped those finds, they saw that the objects were clustered at specific locations on the site.

From the arrangement of the pieces and the kind of burning they underwent, as well as climatic and geological factors, the scholars' paper concludes that the flames could not have been produced by lightning strikes, peat fires, or volcanoes.

The use of fire required sophisticated mental abilities, she suggests. Furthermore, the skill encouraged the development of more complex behavior. For example, fire is used for cooking, which enables humans to expand their diet. She has also found seeds of the prickly water lily in the ancient strata. "The prickly water lily nut is very hard-coated," she says. "You need to roast it before you can crack it."

A Modern Style

Experts on prehistoric man concur that Gesher Benot Ya'aqov is a key site with an abundance of evidence seldom found elsewhere for comparable periods. They also acknowledge Ms. Goren-Inbar's skill as an excavator and her painstaking analysis of her finds. But has she really clinched her case? Were the early humans living at GBY able to plan and execute complex operations, engage in symbolic thinking, and communicate their thoughts to each other?

"The problem is, what is the standard of modernity?" says John D. Speth, a professor of anthropology at the University of Michigan at Ann Arbor. Many scholars, he explains, maintain that the first humans who can be termed "modern" lived about 40,000 years ago because it is only since then that humans have left behind artifacts — cave paintings, elaborate burial sites — that remind us of our own culture. But that claim is based on a lot of tacit assumptions about what kinds of activities are advanced and what kinds are primitive.

"Everyone assumes a one-to-one link — if the archaeology looks more complex, then the people who produced it were more cognitively sophisticated," he says. "But that's an assumption that remains unevaluated."

Iain Davidson, an archaeologist and paleoanthropologist at the University of New England in Australia, says arguments like Ms. Goren-Inbar's are anthropomorphic. "The point is that the Acheuleans are neither chimps nor modern humans," he says. "We automatically tend to think that we need to find out how human they were rather than how apelike they were. Sometimes it's better to think about whether an ape could do these things." Mr. Davidson has argued in his work that language, and the cognition that comes with it, seems to come relatively late in human prehistory, only tens of thousands of years ago.

Coordinated hunting, Mr. Davidson notes, is not a uniquely human behavior. Lions, for example, hunt in coordinated groups.

"There's no doubt that an animal like a lion sets out to kill another animal, and we call that hunting," he says. "If hunting means killing an animal, then it's quite likely that early hominins — the precursors of modern humans — were capable of it. But when hunting turns into modern behavior, it is much more organized than just killing an animal."

Mr. Davidson says he would like to see more-detailed patterns of evidence to support the conclusion that the Acheuleans were engaged in modern hunting behavior. Oxford's Mr. Roe thinks, like Ms. Goren-Inbar, that the evidence at GBY seems to indicate a hunt so complex that it is hard to imagine how the operation was carried out without someone giving clear verbal instructions.

"On the other hand," he adds, "one might say, 'But look at the way birds teach each other to build complex nests.' I always think about those complicated weaverbird nests. Each generation is able to make them. All animal behavior is taught — or whatever is equivalent to that — much of it by imitation."

Chimpanzees, he notes, use tools and display culturally determined behavior. And some chimps are better than others at learning those skills. But none of that is done with language.

"Could people really have been taught how to make an African cleaver, how to strike the flakes off a rock?" Mr. Roe asks. "Can that be done just by demonstration? It would certainly be a lot easier to do it in words."

Language Lessons

The real problem for archaeologists is that language doesn't fossilize. How could a nonwriting society leave behind evidence of a working spoken language? researchers wonder.

"Archaeologists lack a clear link between language and behaviors that leave evidence in the archaeological record," says John J. Shea, an associate professor of anthropology at the State University of New York at Stony Brook. "Take hunting: There's no agreement that language is necessary for that. The people at GBY were big-brained creatures, probably Homo erectus. They were probably social, probably hunting. They probably had a sophisticated communications system. They were probably linguistic in some way, but not in the same complex way we are."

"We use language to assign people to social groups, to label symbols, to use symbols outside our bodies," Mr. Shea says. "Burial and painting show up late in the course of human evolution. Does that mean that language was also late? Or was there some kind of proto-language that lacks some features we see in contemporary language?"

Some scholars believe that there were physiological constraints on the development of language, perhaps in the anatomy of the brain. In this view, early humans, like the Acheuleans, probably did not have the brain structures required for language. But since brains are not preserved in the fossil record, there is no way to compare the brain of an Acheulean with that of modern humans.

All of the skeptics agree, however, that GBY is one of the few sites that provides the kind of evidence that makes it possible even to approach the issues of cognition and language.

"Naama is absolutely right that there is a lot of sophistication present," says Michigan's Mr. Speth. There is an unspoken assumption, he notes, that humans from 40,000 years ago were more advanced than the Acheuleans; we find, for example, cave paintings associated with human remains from 40,000 years ago, while the Acheuleans seem not to have painted. Nonetheless, he argues, the Acheuleans could have been capable of cave painting, yet did not engage in that activity for some other reason.

"What I'm prepared to say," says Mr. Davidson, "is that the claims being made about GBY are the right sort of claims to capture these arguments. But I still want to do a lot more work before I concede that yes, I was wrong" about language emerging relatively recently in human history.

Some of the answers may come from the bank of the Jordan River here, where Ms. Goren-Inbar stands doubled over like a rice farmer. She runs her fingers through the mud and finally stands up with a smile. "Here's a bone fragment," she announces, "and here's a flint."

It is a momentary success — one that highlights a painful reality for archaeologists. In 1999 the Israeli government brought heavy earthmoving equipment here, under cover of night, in violation of the country's antiquities law. To help prevent flooding upstream, the engineers dredged the river near the bridge, dumping sediments on the bank and damaging the valuable GBY site. Researchers like Ms. Goren-Inbar will now have to retreat to their collections and look for clues among the carefully excavated finds from many strata and many different sites.

A truck thunders over the bridge. The kayakers are gone. It's time, she says, to return to her office in Jerusalem and get back to work.