The mysteries surrounding the migration routes of the earliest modern humans in East Asia have long captivated anthropologists and archaeologists alike. While there is a growing consensus on when and where these populations settled, the methods by which they crossed treacherous stretches of open sea have remained elusive. Now, a groundbreaking collaboration between Japanese and Taiwanese researchers, led by Professor Yousuke Kaifu from the University of Tokyo, has thrown new light on these ancient voyages. Combining cutting-edge numerical simulations with experimental archaeology, the team recreated the perilous sea crossings made some 30,000 years ago, revealing sophisticated seafaring capabilities previously unimagined for Paleolithic humans.
Around 30,000 years ago, prehistoric humans undertook a remarkable migration across the East China Sea, traversing from what is now Taiwan to the southern Japanese archipelago, including islands like Okinawa. This region is dominated by one of the world’s strongest ocean currents, the Kuroshio Current, whose powerful and unpredictable flow presents a formidable challenge to navigation. To better understand how these sea crossings could have been feasible without modern navigational aids, metal tools, or maps, Kaifu’s team conducted rigorous simulations and built authentic replicas of period-accurate watercraft. Their approach merged computational oceanography with hands-on experimental voyages, creating a comprehensive picture of Paleolithic seafaring.
The numerical simulations focused on modeling the Kuroshio Current’s complex hydrodynamics and how a craft from the Paleolithic era might interact with such powerful flows. Utilizing advanced particle tracking techniques, the simulations incorporated variables such as seasonal changes, starting points, and paddling strategies to assess the feasibility of successful crossings. Contrary to prior assumptions that entry into this swift current would lead to aimless drifting, the models revealed that with proper skill and strategy, early humans could have intentionally navigated these waters, compensating for the current’s force by adjusting their heading. This suggested an unexpectedly high level of nautical understanding and tactical adaptability among these prehistoric seafarers.
Complementing the simulations, the team embarked on an audacious real-world experiment to test the viability of Paleolithic seafaring craft. In 2019, they constructed a 7.5-meter dugout canoe called Sugime from a single Japanese cedar trunk, fashioned entirely with replicas of 30,000-year-old stone tools. This endeavor was grounded in experimental archaeology, aiming to gain firsthand insight into the physical and technical challenges faced by ancient mariners. The Sugime was paddled over 225 kilometers from eastern Taiwan to Yonaguni Island—part of the Ryukyu chain—guided only by natural indicators such as the sun, stars, ocean swells, and instinct, mirroring the conditions of their Paleolithic predecessors.
The voyage aboard Sugime lasted over 45 continuous hours, during which the paddlers faced overwhelming isolation and limited visibility of their destination for most of the journey. Navigating without modern maps or instruments, the crew relied heavily on archaic seafaring knowledge—a blend of environmental observation and experiential learning. This feat underscored the physical endurance and psychological resilience necessary for such undertakings in prehistory. The success of this journey provided tangible evidence that dugout canoes, crafted with stone tools, were not only seaworthy but capable of sustained oceanic travel through one of the planet’s most challenging marine currents.
Before settling on the dugout canoe hypothesis, the research group rigorously explored alternate vessel types, including rafts, which are often proposed in Paleolithic maritime theories. However, multiple test expeditions with raft replicas revealed significant limitations: such crafts lacked the speed required to cross the Kuroshio Current within a practical timeframe and demonstrated insufficient durability in the face of the ocean’s relentless forces. The dugout canoe, by contrast, offered superior hydrodynamics and reliability, positioning it as the most plausible craft enabling early humans to reach remote islands in East Asia. This realization recalibrates our understanding of ancient maritime technology and strategy in the region.
Strategic knowledge was critical to these early crossings. The simulations indicated that launching from northern Taiwan was more advantageous, offering a higher probability of success compared to further southern departure points. Furthermore, paddling tactics were essential: instead of aiming directly at their target island, paddlers had to adjust their course southeastward to counteract the lateral displacement caused by the current. This subtlety suggests a sophisticated grasp of oceanic navigation and environmental conditions. Such skills would have been developed through cumulative voyaging experience and knowledge transmission among early human groups.
This research also highlights broader patterns in human migration and cognitive evolution. The ability to undertake perilous sea journeys without modern navigational technology points to the ingenuity and determination of Paleolithic people. Professor Kaifu draws parallels with the Polynesian navigators who traversed the vast Pacific centuries later, relying on natural cues such as celestial bodies, ocean swells, and wind patterns to maintain their course. The simulated and experimental findings lend support to the hypothesis that similar natural maritime knowledge and techniques could have emerged, and been mastered, far earlier in human history than previously documented.
Oceanographic expertise underpinned much of the numerical modeling in this study. Dr. Yu-Lin Chang, a specialist in marine science and particle tracking, adapted techniques traditionally used to investigate phenomena like eel and salmon migrations, volcanic pumice drift, and oil spill dispersal to reconstruct ancient human voyages. This interdisciplinary approach bridged archaeology and oceanography, enabling the researchers to generate data-driven insights into the feasibility of Paleolithic seafaring. The results exceeded Dr. Chang’s expectations, showcasing the potential of ocean currents as navigable pathways rather than insurmountable barriers.
The culmination of these efforts is a compelling narrative of human resilience and adventure. The journey across the Kuroshio Current was not merely a random drift but a deliberate, skillful crossing demanding extensive preparation and cooperation. These findings challenge the traditional portrayal of early humans as predominantly land-bound wanderers, instead positioning them as adept explorers capable of maritime innovation. The intersection of experimental archaeology and ocean modeling proves invaluable in reconstructing these ancient migrations, filling gaps left by the sparse archaeological record.
Significantly, the data obtained through field experiments and simulations continue to inspire further inquiries. The team’s ongoing analyses seek to refine migration models, address questions about return journeys, and elucidate how Paleolithic populations managed risk during long sea crossings. As Professor Kaifu noted, the absence of maps resulted in one-way voyages; unlike later seafarers, these pioneers likely did not make return trips, underscoring both the peril and the commitment involved. Understanding these dynamics offers profound insight into the human story of exploration, survival, and adaptation.
This research carries implications beyond East Asian archaeology, prompting a reevaluation of worldwide human dispersals and the methods employed for island colonization. As maritime technology proved vital to the spread of anatomically modern humans, recognizing the sophistication of these early maritime practices shifts paradigms about the timing and complexity of human expansion. Future investigations building on this foundation may reveal similar advanced seafaring behaviors in other regions, reshaping our understanding of early human technological and cognitive capacities.
In conclusion, the pioneering work from Professor Kaifu and his multidisciplinary team demonstrates that the earliest modern humans in East Asia were not merely passive recipients of chance but active navigators who harnessed environmental knowledge and crafted effective sea vessels to overcome daunting natural obstacles. The synergy of experimental and computational studies has unveiled a vivid tableau of Paleolithic maritime migration—one marked by ingenuity, endurance, and strategic acumen. Such revelations enrich the tapestry of human prehistory and inspire fresh perspectives on our species’ enduring quest to explore the unknown.
Subject of Research: People
Article Title: Traversing the Kuroshio: Paleolithic migration across one of the world’s strongest ocean currents
News Publication Date: 25-Jun-2025
References:
- Yu-Lin K. Chang, Yasumasa Miyazawa, Xinyu Guo, Sergey Varlamov, Haiyan Yang, Yousuke Kaifu, “Traversing the Kuroshio: Paleolithic migration across one of the world’s strongest ocean currents”, Science Advances
- Yousuke Kaifu, Chih-Hsing Lin, Nobuyuki Ikeya, Masahisa Yamada, Akira Iwase, Yu-Lin K. Chang, Masahiro Uchida, Koji Hara, Kunihiro Amemiya, Yunkai Sung, et al., “Palaeolithic seafaring in East Asia: an experimental test of the dugout canoe hypothesis”, Science Advances
Image Credits: ©2025 Kaifu et al. CC-By-ND
Web References:
DOI: 10.1126/sciadv.adv5508
Keywords: Paleolithic migration, Kuroshio Current, seafaring, dugout canoe, experimental archaeology, numerical simulation, East Asia, ancient navigation, prehistoric voyaging, human dispersal, ocean modeling, early seafaring technology
