In a remarkable journey illuminating the seafaring prowess of ancient humans, a team of scientists from Japan and Taiwan recreated a maritime crossing that may have occurred 30,000 years ago. Led by Professor Yousuke Kaifu, an anthropologist from the University of Tokyo, the researchers detailed their findings in two new studies published on June 25 in the journal Science Advances.
The team used period-accurate tools to construct a 7.5-meter-long dugout canoe named Sugime, crafted from a single Japanese cedar trunk. Emulating Paleolithic methods, they relied on replicas of stone tools from that era, including axes and adzes, to build the vessel. According to Reuters, the scientists then paddled Sugime approximately 140 miles (225 kilometers) from eastern Taiwan to Yonaguni Island in southern Japan's Ryukyu group.
The voyage was undertaken by a crew of five—four men and one woman—who paddled for over 45 hours across the open sea. Enduring extreme fatigue, they took breaks while the canoe drifted, much like their ancient counterparts might have done. Navigating without modern instruments, they charted their course by following the sun, stars, ocean swells, and their instincts.
"Through the project with many failures, we learned the difficulties of crossing the ocean, and this experience gave us a deep respect for our Paleolithic ancestors," Kaifu said, according to Reuters. "We found that the Paleolithic people could cross the sea with the strong ocean current if they had dugout canoes and were skillful, experienced paddlers and navigators."
The team's endeavor aimed to demonstrate how prehistoric people may have accomplished similar trips as they spread to Pacific islands. Archaeological evidence suggests that around 30,000 years ago, humans made sea crossings from present-day Taiwan to islands in southern Japan, including Okinawa. These journeys, potentially ranging from 138 to about 450 miles, were accomplished without metal tools, maps, or modern boats.
One of the greatest challenges faced by both ancient voyagers and the modern team is the Kuroshio Current, one of the world's strongest ocean currents, comparable in strength to the Gulf Stream off Mexico. The current presented an obstacle, necessitating not only durable vessels but also seafaring knowledge. Previous attempts by the researchers using reed and bamboo rafts proved unsuccessful, as these crafts were too slow and not durable enough to overcome the powerful current.
"A dugout canoe was our last candidate among the possible Paleolithic seagoing crafts for the region," Kaifu explained. "We first hypothesized that Paleolithic people used rafts, but after a series of experiments, we learned that these rafts are too slow to cross the Kuroshio and are not durable enough."
To further understand the ancient mariners' strategies, the team conducted ocean simulations. They tested variables, including different starting points, seasons, and paddling strategies under both ancient and modern ocean conditions. The simulations revealed that launching a vessel from northern Taiwan offered seafarers a better chance of success than from points further south. Paddling slightly southeast instead of directly toward the destination was essential for compensating against the powerful current.
"The Kuroshio Current is generally considered dangerous to navigate," said Yu-Lin Chang, a physical oceanographer and study co-author, according to Phys.org. "I thought if you entered it, you could only drift aimlessly. But the results of our simulations went far beyond what I had imagined. I'm pleased this work helped illuminate how ocean voyages may have occurred 30,000 years ago."
These findings suggest a high level of strategic seafaring knowledge among early modern humans in the area. "Scientists try to reconstruct the processes of past human migrations, but it is often difficult to examine how challenging they really were," Kaifu said. "One important message from the whole project was that our Paleolithic ancestors were real challengers. Like us today, they had to undertake strategic challenges to advance."
Reflecting on the courage and skill of these early explorers, Kaifu added, "Those male and female pioneers must have all been experienced paddlers with effective strategies and a strong will to explore the unknown." While the team demonstrated that such a journey was possible with the technology of the time, they believe a return journey toward Taiwan was unlikely. "If you have a map and know the flow pattern of the Kuroshio, you can plan a return journey, but such things probably did not take place until much later in history," he noted.
Written with the help of a news-analysis system.