Latest news with #ScienceAdvances
International Business Times
5 hours ago
- Science
- International Business Times
Scientists Discover Ghostly 23,000-Year-Old Human Footprints in New Mexico; Origin Timeline to be Rewritten?
There is proof that people have been roaming the Americas for at least 20,000 years in the White Sands, a vast area of undulating gypsum dunes left by ancient seas in New Mexico. A portion of White Sands is under US army control as a missile range, but the majority of the area is protected as a national park. Researchers discovered clay footprints in this region that were preserved beneath the gypsum and have altered the chronology of human habitation in the Americas. In the past, we believed that humans first appeared in North America between 13,200 and 15,500 years ago. But according to a recent study led by Vance Holliday, an archeologist from the University of Arizona, and published in Science Advances, the footprints are between 20,700 and 22,400 years old based on evidence from mud, Ruppia seeds, and pollen discovered in layers above and below the trace fossils. This indicates that during the last Ice Age, people crossed a floodplain on the edges of the now-gone Lake Otero, which formerly occupied about 4,140 square kilometers (1,600 square miles) of the Tularosa Basin. Holliday and his colleagues said, "Pleistocene lakes and associated biological resources in western and southwestern North America must have attracted foragers, but archaeologists have surveyed few paleolake basins." When the footprints were first found in 2021, embedded seeds and pollen were dated between 21,000 and 23,000 years ago. However, since these biomaterials are lightweight and easily moved in such a dynamic ecosystem, some questioned the method used to determine the age of the footprints. However, the new study discovered that mud layer analysis supports the information provided by plant traces. "Most of this dating of organic matter from palustrine muds complement the dating of the seeds and pollen previously reported," the authors stated in the report. Holliday said, "It would be serendipity in the extreme to have all these dates giving you a consistent picture that's in error."
Observer
8 hours ago
- Science
- Observer
With a primitive canoe, scientists replicate prehistoric seafaring
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. 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 THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES 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
The Hindu
8 hours ago
- Health
- The Hindu
Extreme heat silently accelerates ageing on a molecular level
What if extreme heat not only leaves you feeling exhausted but actually makes you age faster? Scientists already know that extreme heat increases the risk of heat stroke, cardiovascular disease, kidney dysfunction and even death. I see these effects often in my work as a researcher studying how environmental stressors influence the aging process. But until now, little research has explored how heat affects biological aging: the gradual deterioration of cells and tissues that increases the risk of age-related diseases. Research my team and I published in the journal Science Advances in March 2025 suggests that long-term exposure to extreme heat may speed up biological ageing at the molecular level, raising concerns about the long-term health risks posed by a warming climate. Extreme heat's hidden toll on the body My colleagues and I examined blood samples from over 3,600 older adults across the United States. We measured their biological age using epigenetic clocks, which capture DNA modification patterns – methylation – that change with age. DNA methylation refers to chemical modifications to DNA that act like switches to turn genes on and off. Environmental factors can influence these switches and change how genes function, affecting aging and disease risk over time. Measuring these changes through epigenetic clocks can strongly predict age-related disease risk and lifespan. Research in animal models has shown that extreme heat can trigger what's known as a maladaptive epigenetic memory, or lasting changes in DNA methylation patterns. Studies indicate that a single episode of extreme heat stress can cause long-term shifts in DNA methylation across different tissue types in mice. To test the effects of heat stress on people, we linked epigenetic clock data to climate records to assess whether people living in hotter environments exhibited faster biological aging. We found that older adults residing in areas with frequent very hot days showed significantly faster epigenetic aging compared with those living in cooler regions. For example, participants living in locations with at least 140 extreme heat days per year – classified as days when the heat index exceeded 90 degrees Fahrenheit (32.33 degrees Celcius) – experienced up to 14 months of additional biological aging compared with those in areas with fewer than 10 such days annually. This link between biological age and extreme heat remained even after accounting for a wide range of individual and community factors such as physical activity levels and socioeconomic status. This means that even among people with similar lifestyles, those living in hotter environments may still be aging faster at the biological level. Even more surprising was the magnitude of the effect – extreme heat has a comparable impact on speeding up aging as smoking and heavy alcohol consumption. This suggests that heat exposure may be silently accelerating ageing, at a level on par with other major known environmental and lifestyle stressors. Long-term public health consequences While our study sheds light on the connection between heat and biological aging, many unanswered questions remain. It's important to clarify that our findings don't mean every additional year in extreme heat translates directly to 14 extra months of biological aging. Instead, our research reflects population-level differences between groups based on their local heat exposure. In other words, we took a snapshot of whole populations at a moment in time; it wasn't designed to look at effects on individual people. Our study also doesn't fully capture all the wayspeople mightprotect themselves from extreme heat. Factors such as access to air conditioning, time spent outdoors and occupational exposure all play a role in shaping personal heat exposure and its effects. Some individuals may be more resilient, while others may face greater risks due to preexisting health conditions or socioeconomic barriers. This is an area where more research is needed. What is clear, however, is that extreme heat is more than just an immediate health hazard – it may be silently accelerating the aging process, with long-term consequences for public health. Older adults are especially vulnerable because aging reduces the body's ability to regulate temperature effectively. Many older individuals also take medications such as beta-blockers and diuretics that can impair their heat tolerance, making it even harder for their bodies to cope with high temperatures. So even moderately hot days, such as those reaching 80 degrees Fahrenheit (26.67 degrees Celcius), can pose health risks for older adults. As the U.S. population rapidly ages and climate change intensifies heat waves worldwide, I believe simply telling people to move to cooler regions isn't realistic. Developing age-appropriate solutions that allow older adults to safely remain in their communities and protect the most vulnerable populations could help address the hidden yet significant effects of extreme heat. (Eunyoung Choi, postdoctoral associate in Gerontology, University of Southern California) This article is republished from The Conversation under a Creative Commons license. Read the original article here:
Bloomberg
13 hours ago
- Health
- Bloomberg
There's a ‘Double-Edged Sword' in Your Stomach
It's not always obvious which of the multitude of species of bacteria riding around in us should be classified as germs and attacked, and which are essential workers that should be nurtured. One that's particularly hard to classify is H. pylori, which was the subject of the 2005 Nobel Prize for the discovery that it causes peptic ulcers. But more recent studies have connected it with benefits, including lowering the risk of esophageal cancer. In a paper published in Science Advances, researchers in Sweden described how the bacteria can inhibit the formation of amyloid deposits, which are found in the brains of individuals with Alzheimer's and Parkinson's disease.
Yomiuri Shimbun
20 hours ago
- Science
- Yomiuri Shimbun
Humans May Have Crossed from Taiwan to Yonaguni 30,000 Years Ago; Strategically Navigated Currents Following Sun, Stars
It is possible Paleolithic humans in a rowboat were able to cross from Taiwan to Yonaguni Island, Okinawa Prefecture, 30,000 years ago, according to an analysis by a research team from the University of Tokyo and other organizations. The team conducted an experimental voyage using a reproduction wooden boat and analyzed ocean currents using a supercomputer. As a result, they found travel across the sea would have been possible, depending on the skill of those in the boat. The result was published in the scientific journal Science Advances. Japanese ancestors are thought to have arrived from the continent via three routes: Hokkaido, Tsushima Island and the Ryukyu Islands. Arrival via the Ryukyu Islands route is believed to have taken place around 35,000 to 30,000 years ago during the late Paleolithic period. However, as Taiwan and Yonaguni Island are separated by the Kuroshio current, a strong ocean current with a speed of 1 to 2 meters per second, how they crossed the sea had been a mystery. In 2019, a research team from the National Museum of Nature and Science and other institutions conducted a 225-kilometer experimental voyage in a wooden boat made from a hollowed-out cedar tree. Five paddlers departed from the east coast of Taiwan and reached Yonaguni Island in 45 hours, navigating based on the position of the sun and stars. Later, the Japan Agency for Marine-Earth Science and Technology and others used a supercomputer to perform numerical simulations to investigate the conditions 30,000 years ago and found the Kuroshio current was 10%-20% faster than today. Based on the results of the experimental voyage, they conducted a hypothetical test with the boat having a maximum speed of 1.08 meters per second, and, taking into account the flow of the current, found the probability of a successful voyage would increase if the boat was paddled at an angle slightly against the Kuroshio current. 'We have discovered our ancestors were strategic explorers who understood the effects of ocean currents and used their skillful navigation techniques to cross the sea,' said University of Tokyo Prof. Yosuke Kaifu, head of the research team.
