Erectus Ahoy

As the sun edged above the horizon on Jan. 31, 2000, a dozen men boarded a bamboo raft off the east coast of the Indonesian island of Bali. Each gripped a wooden paddle and, in unison, deftly stroked the nearly 40-foot-long craft into the open sea. Their destination: the Stone Age, by way of a roughly 18-mile crossing to the neighboring island of Lombok. Project director Robert G. Bednarik, one of the assembled paddlers, knew that a challenging trip lay ahead, even discounting any time travel. Local fishing crews had told him of the Lombok Strait’s fiendishly shifting currents, vicious whirlpools, and unexpected waves far from shore. No matter—Bednarik knew of no other way to demonstrate that Homo erectus, humanity’s evolutionary precursor and perhaps a direct ancestor of Homo sapiens, was the world’s first seafarer.

Such a possibility falls far outside mainstream ideas about the origins of sea travel. Many researchers theorize that Southeast Asian H. sapiens built and navigated the first sea vessels between 60,000 and 40,000 years ago, ultimately piloting them to the open spaces of Australia. However, archaeologists have found precious few remains of prehistoric rafts and boats. The oldest such finds, including wooden canoes and paddles, come from northern Europe and date to at most 9,000 years ago.

Nonetheless, Bednarik says, it’s apparent that H. erectus—which may have survived in Java until 30,000 years ago—launched the first age of ocean journeys between 900,000 and 800,000 years ago. On Flores, an island separated from Bali by ocean waters and the islands of Lombok and Sumbawa, other scientists have dated stone tools at more than 800,000 years old (SN: 3/14/98, p. 164). Although a land bridge connected Bali to mainland Asia at that time, it’s unlikely such walkways existed between the other islands, in Bednarik’s view.

If hardy teams of H. erectus reached Flores by sea, their mode of transportation remains unknown. Some scientists suspect that small numbers of Stone Age folk accidentally drifted as far as Flores after climbing onto thick mats of vegetation that sometimes form near the Southeast Asian coast.

That speculation doesn’t float, contends Bednarik. Only a craft propelled by its occupants could negotiate the treacherous straits separating one Indonesian island from the next. To back up that claim, he launched a project in 1996 to determine what Stone Age groups would have had to do, at a minimum, to reach Flores and its neighboring islands. A lot of hard work, a handful of sea excursions, and a few close calls later, he and his comrades thrust their newest and most improved bamboo raft, dubbed Nale Tasih 4, into the Lombok Strait.

Nearly 12 hours later, after covering a distance of 30 miles, they completed their journey—just barely.

Through it all, Nale Tasih 4 held up well. Bednarik and a team of Indonesian boat makers and craftsmen built the raft out of natural materials, using sharpened stone tools comparable to those wielded by H. erectus. Despite the simplicity of such implements, prehistoric island colonizers must have possessed a broad range of knowledge and skills to assemble rafts on a par with Nale Tasih 4, Bednarik holds.

Ancient seafaring, he adds, coincided with other cultural advances usually attributed by scientists to H. sapiens, such as communicating with a spoken language and creating the carved and painted symbols that we now call art.

“A quantum leap in cognition and technology occurred around 900,000 years ago,” Bednarik says. “All the traits that fundamentally define modern humans were first developed by Homo erectus.”

Island hopping

The millennial voyage of Nale Tasih 4 started out swimmingly. After a couple of hours, the vessel reached deep sea, where it floated two-thirds of a mile above the ocean floor. A stubborn current began to muscle against the raft as 5-foot waves peeled off choppy waters.

Furious paddling produced little headway as the current’s strength increased. Around noon, an exhausted Balinese paddler collapsed. Responding to a call radioed by Bednarik, a support ship picked up the man and dropped off a replacement.

The going stayed rough throughout the afternoon. Crewmembers couldn’t keep the raft from drifting northward in the unrelenting current. Several of them fought off light-headedness brought on by fatigue. It looked as if the crossing might fail.

Then, the wind shifted and the sea calmed. A course correction and final push by the bedraggled paddlers brought Nale Tasih 4 to one of the Gillies Islands, just off Lombok’s west coast, shortly after 6 p.m.

Bednarik cherishes such skin-of-the-teeth crossings. As director of the International Institute of Replicative Archaeology in South Caulfield, Australia, he is working to establish the minimum conditions necessary for H. erectus to have hopped from one island to another. Ancient vessels may not have looked like Nale Tasih 4, but they had to have been technological marvels for their time, if the Lombok Strait crossing is any guide.

Bednarik’s technological explorations began in August 1997, when he directed 7 months of work on Nale Tasih 1, a 70-foot-long, 15-ton bamboo raft. It included two sails of woven palm leaves rigged on A-frame masts.

Bednarik hoped to sail the craft from the Indonesian island of Timor to Australia, recreating the crossing that presumably occurred as many as 60,000 years ago. However, sea trials indicated that the raft was too heavy to maneuver across the Timor Sea.

That experience resulted in Nale Tasih 2, a 58-foot-long, 2.8-ton bamboo raft rigged with a single palm-leaf sail. In December 1998, a crew guided this vessel from Timor to Australia, taking 13 days to travel nearly 600 miles. Two hollow mangrove tree trunks held fresh water for the travelers. Meals consisted of fish caught with bone harpoons and cooked over a small hearth, as well as rations of palm sugar and fruit.

The trip was no picnic, though. At times, Nale Tasih 2 braved tropical storms that whipped up 16-foot waves. The craft suffered extensive damage during these tempests, including a smashed rudder and a shredded sail. The five-man crew used stone tools to repair the damage at sea.

That mission accomplished, Bednarik turned to a simpler, oar-driven crossing from Bali to Flores that he contends happened as many as 750,000 years before the original Timor-to-Australia voyage. In March 1999, six oarsmen directed Nale Tasih 3 eastward from Bali into the Lombok Strait. The expedition was cut short after 6 hours of rowing, when the crew realized that currents had pulled them too far north to reach Lombok’s west coast.

That set the stage for Nale Tasih 4’s grueling demonstration of how H. erectus could have conquered a short but taxing stretch of ocean.

Our Stone Age ancestors were certainly smart enough to have traversed a nautical obstacle course such as the Lombok Strait, Bednarik contended in the April Cambridge Archaeological Journal. Findings by researchers working in Asia and Africa suggest that rock art, decorative beads, engraved stones, and hunting spears all originated at least several hundred thousand years before the appearance of H. sapiens. Such accomplishments would require that individuals speak to one another and assign abstract meanings to various objects and symbols, in Bednarik’s opinion.

He suspects that genetic and cultural evolution played out slowly among human ancestors over the past 2 million years. Groups that moved across Africa and Asia interbred to some extent and passed cultural innovations back and forth.

In this continental melting pot, a hazy biological boundary separated H. erectus from H. sapiens. About 1 million years ago, Stone Age Asians probably congregated near coasts, and their fishing rafts were eventually adapted for sea travel. Remains of these shore inhabitants would have since become submerged and so are unavailable to archaeologists.

In contrast, many scientists maintain that H. sapiens alone developed language and symbolic thought, after having evolved in Africa between 200,000 and 150,000 years ago (SN: 6/14/03, p. 371: African Legacy: Fossils plug gap in human origins). Interbreeding and cultural exchanges played no role in modern humanity’s rise, this camp argues.

Making waves

Bednarik has no qualms about paddling against the academic mainstream. Over the past 30 years, he’s become a self-taught authority on Stone Age rock art. He’s written hundreds of scientific articles and now edits three journals, all without having attended a university or earned an academic degree.

His equally unconventional raft project, reminiscent of Thor Heyerdahl’s 1947 voyage from Peru to Polynesia on a balsa raft, has its supporters.

“Maybe Bednarik is right,” remarks archaeologist Michael J. Morwood of the University of New England in Armidale, Australia. Morwood directs ongoing excavations on Flores.

Only watercraft navigators and especially hardy, swimming creatures reached the island in the thick of the Stone Age, Morwood says. Dating of stone-tool-bearing sediment indicates that H. erectus occupied the island 840,000 years ago, in his view. At that time, fossil discoveries show that rodents and now-extinct elephants also lived there. Modern versions of these animals are renowned as long-distance swimmers.

“[Stone Age] seafaring appears to have been possible,” says anthropologist Tim Bromage of Hunter College, City University of New York. Southeast Asian bamboo that grows in stalks as thick as 12 inches across provides a versatile material for building rafts with the aid of simple stone tools, he notes.

While H. erectus possessed enough smarts to construct rafts and navigate them to nearby islands, Bednarik errs in assuming that the ancient species gradually evolved into modern humanity, maintains anthropologist Russell L. Ciochon of the University of Iowa in Iowa City. Instead, H. erectus evolved in Asia and died out there, while today’s people originated in Africa around 200,000 years ago, Ciochon says.

Some scientists, however, don’t think any part of Bednarik’s theory holds water. Stone Age folk 800,000 years ago didn’t make long-range plans, talk to one another, or form cultural groups, so they couldn’t have organized efforts to build rafts and row to islands, contends archaeologist Iain Davidson of the University of New England in Australia.

For instance, the singular, unchanging appearance of stone tools from disparate regions throughout most of the Stone Age betrays an absence of cultural traditions in making and using such vital implements, Davidson says. Moreover, there’s virtually no evidence of our 800,000-year-old ancestors having practiced group efforts of any kind, he adds. A small number of H. erectus individuals may accidentally have reached Flores, perhaps by floating on mats of vegetation, in Davidson’s opinion.

“It seems premature to rule out the use of natural rafts of vegetation in colonization [of Flores],” remarks archaeologist Matthew Spriggs of Australian National University in Canberra. “May [Bednarik’s] experiments continue.”

The next phase of Bednarik’s rafting experiments has moved to Europe. Proposals that H. erectus intentionally traveled to Mediterranean islands and entered Europe from Africa via the Strait of Gibraltar have attracted considerable controversy (SN: 1/4/97, p. 12).

Bednarik is now directing the construction of rafts made out of cane that grows near the Mediterranean Sea. His team will attempt crossings from the coasts of Greece and Italy to the island of Sardinia, as well as across the Strait of Gibraltar, a channel of water at the Mediterranean’s mouth that separates Europe from Africa.

For now, academic squabbling worries Bednarik far less than the challenge of navigating a raft through the Strait of Gibraltar’s strenuous currents.

“Armchair archaeologists, who think that sea crossings are a piece of cake, really ought to try doing this on drifting vegetation,” he says.

****************

If you have a comment on this article that you would like considered for publication in Science News, send it to editors@sciencenews.org. Please include your name and location.

---