With a primitive canoe, scientists replicate prehistoric seafaring
A dugout canoe with four men and one woman paddling is pictured during a crossing across a region of the East China Sea from near Ushibi, Taiwan to Yonaguni Island, traversing the Kuroshio current, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS
Researcher Kunihiro Amemiya uses a period-accurate axe to chop down a Japanese cedar tree in Noto Peninsula, Japan, to make a dugout canoe for a crossing across a region of the East China Sea from Taiwan to Yonaguni Island, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS
An axe accurate to a period of 30,000 years ago, that scientists used to make a dugout canoe for a crossing across a region of the East China Sea from Taiwan near Ushibi to Yonaguni Island, traversing the Kuroshio current, is seen at Noto Peninsula, Japan, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS
A dugout canoe with four men and one woman paddling is pictured during a crossing across a region of the East China Sea from near Ushibi, Taiwan to Yonaguni Island, traversing the Kuroshio current, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS
A dugout canoe is pictured before departure on a crossing across a region of the East China Sea to Yonaguni Island, with leaf wave guards at the bow and stern, near Ushibi, Taiwan, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS
Our species arose in Africa roughly 300,000 years ago and later trekked worldwide, eventually reaching some of Earth's most remote places. In doing so, our ancestors surmounted geographic barriers including treacherous ocean expanses. But how did they do that with only rudimentary technology available to them?
Scientists now have undertaken an experimental voyage across a stretch of the East China Sea, paddling from Ushibi in eastern Taiwan to Japan's Yonaguni Island in a dugout canoe to demonstrate how such a trip may have been accomplished some 30,000 years ago as people spread to various Pacific Islands.
The researchers simulated methods Paleolithic people would have used and employed replicas of tools from that prehistoric time period such as an axe and a cutting implement called an adze in fashioning the 25-foot-long (7.5-meter) canoe, named Sugime, from a Japanese cedar tree chopped down at Japan's Noto Peninsula.
A crew of four men and one woman paddled the canoe on a voyage lasting more than 45 hours, traveling roughly 140 miles (225 km) across the open sea and battling one of the world's strongest ocean currents, the Kuroshio. The crew endured extreme fatigue and took a break for several hours while the canoe drifted at sea, but managed to complete a safe crossing to Yonaguni.
Just as prehistoric people would have, the voyagers navigated by the sun and stars, as well as the direction of the ocean swells, though for safety's sake they were accompanied by two escort craft. Yonaguni is part of the Ryukyu chain of islands stretching from Kyushu, the southernmost of Japan's four main islands, down to Taiwan.
The researchers previously failed with attempted crossings using reed rafts and then bamboo rafts, finding that they were too slow, insufficiently durable and unable to overcome the strong ocean current.
"Through the project with many failures, we have learned the difficulties of crossing the ocean, and this experience gave us a deep respect for our Paleolithic ancestors," said University of Tokyo anthropologist Yousuke Kaifu, lead author of the study published on Wednesday in the journal Science Advances.
"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. They had to face the risk of being drifted by the strong ocean current and the possibility that they would never be able to come back to their homeland," added Kaifu, who was aboard one of the escort boats.
Archeological evidence indicates that people approximately 30,000 years ago first crossed from Taiwan to some of the Ryukyu islands, which include Okinawa. But scientists had puzzled over how they could do this with the rudimentary technology of the time - no maps, no metal tools and only primitive vessels. And the Kuroshio current, comparable in strength to the Gulf Stream off Mexico, presented a particular challenge.
The research was in the vein of the famous 1947 Kon-Tiki expedition in which Norwegian explorer Thor Heyerdahl carried out a much longer journey by raft from South America across the Pacific to the Polynesian islands. Heyerdahl aimed to show how prehistoric people from the Americas could have colonized Polynesia.
"His theory is now countered by a series of pieces of evidence, but it was a great trial at the time. Compared to the time of the Kon-Tiki, we have more archeological and other evidence to build realistic models" of prehistoric voyages, Kaifu said.
The researchers in a companion study published in the same journal used simulations of sea conditions between Taiwan and Yonaguni 30,000 years ago to examine whether such a crossing was attainable at a time when the Kuroshio was even more powerful than today.
"As our paleo-ocean model simulation showed, crossing the Kuroshio was possible in ancient times, so I believe they achieved it," said physical oceanographer and study lead author Yu-Lin Chang of the Japan Agency for Marine-Earth Science and Technology.
"However, ocean conditions were highly variable. Thus, ancient people may have encountered unpredictable weather conditions during their journey, which could have led to failure," Chang added. REUTERS
Join ST's Telegram channel and get the latest breaking news delivered to you.
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Straits Times
5 hours ago
- Straits Times
With a primitive canoe, scientists replicate prehistoric seafaring
A dugout canoe with four men and one woman paddling is pictured during a crossing across a region of the East China Sea from near Ushibi, Taiwan to Yonaguni Island, traversing the Kuroshio current, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS Researcher Kunihiro Amemiya uses a period-accurate axe to chop down a Japanese cedar tree in Noto Peninsula, Japan, to make a dugout canoe for a crossing across a region of the East China Sea from Taiwan to Yonaguni Island, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS An axe accurate to a period of 30,000 years ago, that scientists used to make a dugout canoe for a crossing across a region of the East China Sea from Taiwan near Ushibi to Yonaguni Island, traversing the Kuroshio current, is seen at Noto Peninsula, Japan, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS A dugout canoe with four men and one woman paddling is pictured during a crossing across a region of the East China Sea from near Ushibi, Taiwan to Yonaguni Island, traversing the Kuroshio current, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS A dugout canoe is pictured before departure on a crossing across a region of the East China Sea to Yonaguni Island, with leaf wave guards at the bow and stern, near Ushibi, Taiwan, in this handout image released on June 25, 2025. Yousuke Kaifu/Handout via REUTERS Our species arose in Africa roughly 300,000 years ago and later trekked worldwide, eventually reaching some of Earth's most remote places. In doing so, our ancestors surmounted geographic barriers including treacherous ocean expanses. But how did they do that with only rudimentary technology available to them? Scientists now have undertaken an experimental voyage across a stretch of the East China Sea, paddling from Ushibi in eastern Taiwan to Japan's Yonaguni Island in a dugout canoe to demonstrate how such a trip may have been accomplished some 30,000 years ago as people spread to various Pacific Islands. The researchers simulated methods Paleolithic people would have used and employed replicas of tools from that prehistoric time period such as an axe and a cutting implement called an adze in fashioning the 25-foot-long (7.5-meter) canoe, named Sugime, from a Japanese cedar tree chopped down at Japan's Noto Peninsula. A crew of four men and one woman paddled the canoe on a voyage lasting more than 45 hours, traveling roughly 140 miles (225 km) across the open sea and battling one of the world's strongest ocean currents, the Kuroshio. The crew endured extreme fatigue and took a break for several hours while the canoe drifted at sea, but managed to complete a safe crossing to Yonaguni. Just as prehistoric people would have, the voyagers navigated by the sun and stars, as well as the direction of the ocean swells, though for safety's sake they were accompanied by two escort craft. Yonaguni is part of the Ryukyu chain of islands stretching from Kyushu, the southernmost of Japan's four main islands, down to Taiwan. The researchers previously failed with attempted crossings using reed rafts and then bamboo rafts, finding that they were too slow, insufficiently durable and unable to overcome the strong ocean current. "Through the project with many failures, we have learned the difficulties of crossing the ocean, and this experience gave us a deep respect for our Paleolithic ancestors," said University of Tokyo anthropologist Yousuke Kaifu, lead author of the study published on Wednesday in the journal Science Advances. "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. They had to face the risk of being drifted by the strong ocean current and the possibility that they would never be able to come back to their homeland," added Kaifu, who was aboard one of the escort boats. Archeological evidence indicates that people approximately 30,000 years ago first crossed from Taiwan to some of the Ryukyu islands, which include Okinawa. But scientists had puzzled over how they could do this with the rudimentary technology of the time - no maps, no metal tools and only primitive vessels. And the Kuroshio current, comparable in strength to the Gulf Stream off Mexico, presented a particular challenge. The research was in the vein of the famous 1947 Kon-Tiki expedition in which Norwegian explorer Thor Heyerdahl carried out a much longer journey by raft from South America across the Pacific to the Polynesian islands. Heyerdahl aimed to show how prehistoric people from the Americas could have colonized Polynesia. "His theory is now countered by a series of pieces of evidence, but it was a great trial at the time. Compared to the time of the Kon-Tiki, we have more archeological and other evidence to build realistic models" of prehistoric voyages, Kaifu said. The researchers in a companion study published in the same journal used simulations of sea conditions between Taiwan and Yonaguni 30,000 years ago to examine whether such a crossing was attainable at a time when the Kuroshio was even more powerful than today. "As our paleo-ocean model simulation showed, crossing the Kuroshio was possible in ancient times, so I believe they achieved it," said physical oceanographer and study lead author Yu-Lin Chang of the Japan Agency for Marine-Earth Science and Technology. "However, ocean conditions were highly variable. Thus, ancient people may have encountered unpredictable weather conditions during their journey, which could have led to failure," Chang added. REUTERS Join ST's Telegram channel and get the latest breaking news delivered to you.
Straits Times
7 hours ago
- Straits Times
For first time, Webb telescope discovers an alien planet
The planet orbits its host star, called TWA 7, at a distance about 52 times greater than Earth's orbital distance from the sun. PHOTO: REUTERS WASHINGTON - In addition to providing a trove of information about the early universe, the James Webb Space Telescope since its 2021 launch has obtained valuable data on various already-known planets beyond our solar system, called exoplanets. Now, for the first time, Webb has discovered an exoplanet not previously known. Webb has directly imaged a young gas giant planet roughly the size of Saturn, our solar system's second-largest planet, orbiting a star smaller than the sun located about 110 light years from Earth in the constellation Antlia, researchers said. A light-year is the distance light travels in a year – 5.9 trillion miles or 9.5 trillion km. Most of the roughly 5,900 exoplanets discovered since the 1990s have been detected using indirect methods, such as through observation of the slight dimming of a star's light when a planet passes in front of it, called the transit method. Less than 2 per cent of them have been directly imaged, as Webb did with the newly identified planet. While this planet is large when considered in the context of our solar system, it is actually the least massive one ever discovered through direct imaging – 10 times less massive than the previous record holder. This speaks to the sensitivity of Webb's instruments. This discovery was achieved using a French-produced coronagraph, a device that blocks out the bright light from a star, installed on Webb's Mid-Infrared Instrument, or MIRI. 'Webb opens a new window – in terms of mass and the distance of a planet to the star – of exoplanets that had not been accessible to observations so far. This is important to explore the diversity of exoplanetary systems and understand how they form and evolve,' said astronomer Anne-Marie Lagrange of the French research agency CNRS and LIRA/Observatoire de Paris, lead author of the study published on June 25 in the journal Nature. The planet orbits its host star, called TWA 7, at a distance about 52 times greater than Earth's orbital distance from the sun. To put that in perspective, our solar system's outermost planet Neptune orbits about 30 times farther from the Sun than Earth. The transit method of discovering exoplanets is particularly useful for spotting those orbiting close to their host star rather than much further out like the newly identified one. 'Indirect methods provide incredible information for planets close to their stars. Imaging is needed to robustly detect and characterise planets farther away, typically 10 times the Earth-to-Sun distance,' Dr Lagrange said. The birth of a planetary system begins with a large cloud of gas and dust – called a molecular cloud – that collapses under its own gravity to form a central star. Leftover material spinning around the star in what is called a protoplanetary disk forms planets. The star and the planet in this research are practically newborns – about 6 million years old, compared with the age of the Sun and our solar system of roughly 4.5 billion years. Because of the angle at which this planetary system is being observed – essentially looking at it from above rather than from the side – the researchers were able to discern the structure of the remaining disk. It has two broad concentric ring-like structures made up of rocky and dusty material and one narrow ring in which the planet is sitting. The researchers do not yet know the composition of the planet's atmosphere, though future Webb observations may provide an answer. They also are not certain whether the planet, being as young as it is, is still gaining mass by accumulating additional material surrounding it. While this planet is the smallest ever directly imaged, it is still much more massive than rocky planets like Earth that might be good candidates in the search for life beyond our solar system. Even with its tremendous capabilities of observing the cosmos in near-infrared and mid-infrared wavelengths, Webb is still not able to directly image Earth-sized exoplanets. 'Looking forward, I do hope the projects of direct imaging of Earth-like planets and searches for possible signs of life will become a reality,' Dr Lagrange said. REUTERS Join ST's Telegram channel and get the latest breaking news delivered to you.
Straits Times
13 hours ago
- Straits Times
Cactus tempura? Japanese tuck into prickly pear superfood
The Opuntia genus, known as prickly pear cactus, is gaining national appeal in Japan for being rich in minerals, dietary fibre and other nutrients. PHOTO: REUTERS TOKYO - Farmers in Japan are cooking up new menus for health-conscious Japanese, with dishes like quiche, pizza toast, skewers, tempura and cold Chinese noodles. They share a common but somewhat unusual ingredient: prickly pear cactus. As one of the few farmers who grow edible cactus in Japan, Miki Deguchi is convinced that the nutrient-packed plant is well on its way to becoming a staple here. The Opuntia genus, known as prickly pear cactus, is gaining national appeal in Japan for being rich in minerals, dietary fibre and other nutrients. It has a mild, refreshing taste and can even be enjoyed uncooked. There's some evidence to back its 'superfood' label. Last year, Chubu University established the Research Initiatives Center for Cactus and Succulent Plant Research for the industrial use of cacti. It's located in the city of Kasugai, Aichi Prefecture, where ornamental cactus cultivation first took off in Japan. Researchers at the centre confirmed that mice fed a diet mixed with cactus pear powder had elevated levels of mucin, a protein that covers the surface of the intestine and blocks viruses, and enhanced immune function. 'I'm convinced that cactus has great potential as a functional food,' said Mamoru Tanaka, an associate professor of food and nutrition at the university who took part in the research. Ms Miki, 63, and her husband Motohiko, 63, grow prickly pear on a Kasugai farm set in a 'satoyama',an area between picturesque mountain foothills and arable flat lands. In May, the sounds of birds chirping and frogs croaking resounded near a row of newly sprouted prickly pear. The shoots grow tender and succulent through the fall. The Deguchis learned to grow the plants in 2015. They now cultivate more than 700 cacti in a paddy acquired from a friend. Named 'Taiyonoha' (Sun Leaves), their plants are sold online and at supermarkets in the city for about 1,800 yen (S$15.9) per kilogram and are also served at high-end restaurants in the prefecture. They are also sold as food for pet turtles. Prickly pear has long been a favorite food in Latin America, but Ms Miki said she and her husband 'want to spread the Japanese way of eating it.' Their website provides information on how to prepare a variety of recipes such as a fluffy and sticky cactus quiche. 'It's even delicious on rice with bonito flakes,' Ms Miki said. Cacti thrive in the desert and are highly resilient. The Deguchis' cacti do not need pesticides, and they easily withstand heavy rains, even when their roots are submerged. Farmers in Kasugai began producing ornamental cacti around 1953 and the city has since grown to one of the foremost centers for the plants in Japan, according to city officials. The Deguchis and one other farmer grow edible cacti, and about 10 restaurants offer menus such as ramen noodles and sweets made with the succulents in the city, they said. Local elementary and junior high schools serve cactus curry with Japanese croquettes, or korokke, several times a year. Experts in Japan and abroad alike are also focusing on the potential of edible cactus as a countermeasure to world population growth and climate change. In 2017, the United Nations' Food and Agriculture Organization highlighted the potential of prickly pear cactus as a resilient and nutritious food source in the face of climate change and food crises. The organisation emphasised the plant's ability to thrive in dry and drought-prone areas, providing food, fodder and water for both humans and livestock. It is already being grown for foodstuffs and livestock feed in about 30 countries around the world, including Mexico. Meanwhile, prickly pear cactus is spreading to other regions of Japan. In May, Watahan Super Center, a supermarket and home center chain that operates mainly in Nagano Prefecture, began selling the plant at some of its stores. KYODO NEWS Join ST's Telegram channel and get the latest breaking news delivered to you.
