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Hindustan Times
4 days ago
- Science
- Hindustan Times
Did UV Rays Doom Neanderthals?
Our ancestral cousins went mysteriously extinct around 40,000 years ago, while humans did not. The demise of one and survival of the other continues to flummox paleoanthropologists—but some researchers now think sunscreen and tailored clothing might have played a role. Around the time Neanderthals bit the dust, a weakening of the Earth's magnetic field resulted in exposure to higher doses of harmful ultraviolet radiation. Clothing would have offered some protection. Both groups wore animal skins, but evidence suggests Neanderthals tended to wear loosefitting cloaks, while Homo sapiens sewed form-fitting garments. Humans also coated themselves with mineral pigments, which would have functioned as an ancient SPF. It is unlikely that these differences in behavior alone would have resulted in the Neanderthals' demise, but researchers think that their exposure to increased radiation would have had detrimental effects. The increased exposure occurred when Earth's north and south magnetic poles began to wander from their traditional positions. The rotation of the planet and its molten core help generate a protective magnetic field that keeps our planet's ozone layer robust and protects us from high-energy particles that constantly flow from the sun. The field is anchored at the poles, where magnetic forces are most concentrated. But small changes in the core can cause the poles to wander. During the twilight of the Neanderthals, such a wandering caused the magnetic field to drop to about 10% of its average strength. Scientists call this the Laschamps event. To test the effects of the Laschamps, Agnit Mukhopadhyay, a University of Michigan space scientist, and his group created 3-D models of what Earth's magnetic field would have looked like during the event. The results, published in the journal Science Advances, showed where the magnetic field was compromised, allowing radiation and particles to slip through. Researchers know the magnetic field went haywire way back then by examining minerals smaller than the width of a human hair found within ancient deep-sea sediments and volcanic rocks. These tiny grains, which contain iron, become magnetized, and their alignment offers clues about the state of Earth's magnetic field at the time. The researchers' analysis suggests Earth's northern and southern latitudes up to 40 degrees would have been disproportionately affected by the weakening. This area in the Northern Hemisphere—including what is today Spain—is where many Neanderthal and Homo sapiens populations lived. 'As an anthropologist, I was intrigued, because I think a lot about how climate and weather might have affected Homo sapiens and other species, but I never thought about space,' said Raven Garvey, a professor of anthropology at the University of Michigan and Mukhopadhyay's co-author. For about a millennium or two, during the Laschamps event, Earth would have experienced higher levels of invisible, cosmic radiation. But the impact of a thinner ozone layer wasn't just about increased radiation exposure. It also would have affected cloud cover, wind belts, rainfall and general weather patterns. 'It's not that the UV kills everybody,' said Alan Cooper, an evolutionary biologist at Charles Sturt University in Australia who wasn't involved in the recent work but has published research with similar conclusions. 'It's climate change. Everything goes completely wild at that point.' Not only did Neanderthals disappear from the fossil record around this time, Cooper added, but so did other species across the disproportionately affected areas. Mukhopadhyay's group suggested two theories of what helped Homo sapiens, who interbred with Neanderthals, to survive: the use of a primitive kind of sunscreen known as ocher—a naturally occurring pigment composed of iron oxide often used for cave art—to protect their bodies from the sun, and clothing that hugged the body and covered more skin. Right around the time of the Laschamps event, there was an uptick in cave art at sites archaeologists have linked to Homo sapiens, according to Cooper. Anthropologists hypothesize that Homo sapiens also used ocher on their skin based on the fact that populations living in Africa and Australia today apply the pigment as a skin protectant, said Andrew Zipkin, an archaeological scientist affiliated with Arizona State University who wasn't involved in the recent study. Ocher is a naturally occurring pigment often used in cave paintings in what is now Spain. Archaeological sites linked to Neanderthals and modern humans have both yielded stone tools called scrapers used for processing animal hides to make them supple and wearable, Garvey said. But researchers have found evidence of a broader clothing-making tool kit at Homo sapiens-related sites. 'We're also seeing things like needles and awls and the kinds of implements that would be very useful to poke holes in these hides and then stitch them together with sinew in the mass production of tailored clothing,' she added. Anthropologists are careful to note that the coincident timing of the Neanderthal extinction and the Laschamps event could have been mere chance. Differences in population sizes and other things could also have made the species's survival less likely, according to Tony Capra, a University of California, San Francisco evolutionary geneticist who wasn't involved in the work. The goal of the recent work, according to the study authors, was to focus on one aspect of a multifaceted mystery. 'Whoever had the tailored clothing probably did have this advantage,' Garvey said. 'But was it exclusive to one group and was it enough to lead to the extinction of one and the proliferation of the other? These are million-dollar questions.' Write to Aylin Woodward at Did UV Rays Doom Neanderthals?
Mint
5 days ago
- Science
- Mint
Did UV rays doom Neanderthals?
What happened to the Neanderthals? Our ancestral cousins went mysteriously extinct around 40,000 years ago, while humans did not. The demise of one and survival of the other continues to flummox paleoanthropologists—but some researchers now think sunscreen and tailored clothing might have played a role. Around the time Neanderthals bit the dust, a weakening of the Earth's magnetic field resulted in exposure to higher doses of harmful ultraviolet radiation. Clothing would have offered some protection. Both groups wore animal skins, but evidence suggests Neanderthals tended to wear loosefitting cloaks, while Homo sapiens sewed form-fitting garments. Humans also coated themselves with mineral pigments, which would have functioned as an ancient SPF. It is unlikely that these differences in behavior alone would have resulted in the Neanderthals' demise, but researchers think that their exposure to increased radiation would have had detrimental effects. The increased exposure occurred when Earth's north and south magnetic poles began to wander from their traditional positions. The rotation of the planet and its molten core help generate a protective magnetic field that keeps our planet's ozone layer robust and protects us from high-energy particles that constantly flow from the sun. The field is anchored at the poles, where magnetic forces are most concentrated. But small changes in the core can cause the poles to wander. During the twilight of the Neanderthals, such a wandering caused the magnetic field to drop to about 10% of its average strength. Scientists call this the Laschamps event. To test the effects of the Laschamps, Agnit Mukhopadhyay, a University of Michigan space scientist, and his group created 3-D models of what Earth's magnetic field would have looked like during the event. The results, published in the journal Science Advances, showed where the magnetic field was compromised, allowing radiation and particles to slip through. Researchers know the magnetic field went haywire way back then by examining minerals smaller than the width of a human hair found within ancient deep-sea sediments and volcanic rocks. These tiny grains, which contain iron, become magnetized, and their alignment offers clues about the state of Earth's magnetic field at the time. The researchers' analysis suggests Earth's northern and southern latitudes up to 40 degrees would have been disproportionately affected by the weakening. This area in the Northern Hemisphere—including what is today Spain—is where many Neanderthal and Homo sapiens populations lived. 'As an anthropologist, I was intrigued, because I think a lot about how climate and weather might have affected Homo sapiens and other species, but I never thought about space," said Raven Garvey, a professor of anthropology at the University of Michigan and Mukhopadhyay's co-author. For about a millennium or two, during the Laschamps event, Earth would have experienced higher levels of invisible, cosmic radiation. But the impact of a thinner ozone layer wasn't just about increased radiation exposure. It also would have affected cloud cover, wind belts, rainfall and general weather patterns. 'It's not that the UV kills everybody," said Alan Cooper, an evolutionary biologist at Charles Sturt University in Australia who wasn't involved in the recent work but has published research with similar conclusions. 'It's climate change. Everything goes completely wild at that point." Not only did Neanderthals disappear from the fossil record around this time, Cooper added, but so did other species across the disproportionately affected areas. Mukhopadhyay's group suggested two theories of what helped Homo sapiens, who interbred with Neanderthals, to survive: the use of a primitive kind of sunscreen known as ocher—a naturally occurring pigment composed of iron oxide often used for cave art—to protect their bodies from the sun, and clothing that hugged the body and covered more skin. Right around the time of the Laschamps event, there was an uptick in cave art at sites archaeologists have linked to Homo sapiens, according to Cooper. Anthropologists hypothesize that Homo sapiens also used ocher on their skin based on the fact that populations living in Africa and Australia today apply the pigment as a skin protectant, said Andrew Zipkin, an archaeological scientist affiliated with Arizona State University who wasn't involved in the recent study. Archaeological sites linked to Neanderthals and modern humans have both yielded stone tools called scrapers used for processing animal hides to make them supple and wearable, Garvey said. But researchers have found evidence of a broader clothing-making tool kit at Homo sapiens-related sites. 'We're also seeing things like needles and awls and the kinds of implements that would be very useful to poke holes in these hides and then stitch them together with sinew in the mass production of tailored clothing," she added. Anthropologists are careful to note that the coincident timing of the Neanderthal extinction and the Laschamps event could have been mere chance. Differences in population sizes and other things could also have made the species's survival less likely, according to Tony Capra, a University of California, San Francisco evolutionary geneticist who wasn't involved in the work. The goal of the recent work, according to the study authors, was to focus on one aspect of a multifaceted mystery. 'Whoever had the tailored clothing probably did have this advantage," Garvey said. 'But was it exclusive to one group and was it enough to lead to the extinction of one and the proliferation of the other? These are million-dollar questions." Write to Aylin Woodward at
Economic Times
22-06-2025
- Science
- Economic Times
They survived ice ages and hunted mammoths; so why did the Neanderthals suddenly disappear? Now a physicist blames something in the sky
Live Events Radiation as a Hidden Killer? A Caution Against Oversimplification (You can now subscribe to our (You can now subscribe to our Economic Times WhatsApp channel Neanderthals have long puzzled scientists. These ancient relatives of modern humans thrived across Europe and parts of Asia for hundreds of thousands of years. But around 40,000 years ago, they disappeared, just as Homo sapiens spread across the same regions. What really caused their extinction remains one of human evolution's biggest a new and unusual theory suggests that space weather, not climate, competition, or disease, may have played a decisive role.A recent study by Dr. Agnit Mukhopadhyay, a space physicist from the University of Michigan , proposes that a powerful cosmic event known as the Laschamp excursion might have played a part in the Neanderthals' decline. The findings were published in the journal Science Laschamp event occurred about 41,000 years ago, when the Earth's magnetic poles temporarily flipped. During this brief reversal, the planet's magnetic field, which normally protects us from cosmic radiation, dramatically weakened for several argues that this weakening may have exposed the Earth's surface to much higher levels of ultraviolet (UV) and cosmic radiation, particularly in some parts of the core of the hypothesis is that Neanderthals, already living in small, isolated populations, may have been more vulnerable to this radiation than Homo sapiens. The study claims that Homo sapiens had tighter clothing, used red ochre as UV protection, and took shelter in caves helping them survive the radiation. Neanderthals, in contrast, might have lacked these simulations in the study even show that auroras, a sign of increased solar activity, might have been visible across much of the world during this time, proof, the author argues, of the heightened radiation the theory is bold and imaginative, many experts are José-Miguel Tejero and Montserrat Sanz Borràs, writing for The Conversation, point out that the idea rests on shaky archaeological example, it assumes that Neanderthals didn't wear fitted clothing. While it's true that no sewing needles have been found at Neanderthal sites, there is clear evidence that they processed animal hides and likely wore functional garments using other techniques, such as tying hides with leather cords or fact, genetic studies of lice suggest that humans, possibly including Neanderthals, were already wearing clothes over 200,000 years ago. The absence of needles doesn't prove the absence of study also claims that Homo sapiens used red ochre as sunblock. While experiments show that ochre can somewhat block UV rays, this claim is also disputed. Ochre was widely used by both Neanderthals and modern humans, often for symbolic or cosmetic reasons. There is no solid evidence that either group used it primarily for sun are known to have used ochre for over 100,000 years. In one example, a painted scallop shell found in a Neanderthal cave in Spain shows their symbolic use of pigments long before Homo sapiens arrived in scientists believe that multiple factors caused the Neanderthals' disappearance. These include, interbreeding with Homo sapiens (evident in modern DNA), smaller populations that were more vulnerable to decline, limited long-range hunting tools, unlike the projectile weapons used by sapiens, Changing climate, and possibly, competition for this broader context, Mukhopadhyay's theory appears too narrow. Critics note that there is no archaeological evidence of a sudden, global collapse of Neanderthal populations tied to the Laschamp event. If radiation were such a major factor, it would have also harmed Homo sapiens populations living outside caves in sunny Africa, which doesn't seem to have Neanderthal story is complex. These early humans were not primitive brutes. They developed tools, built shelters, made symbolic objects, and survived in extreme climates for hundreds of thousands of years. They even lived through earlier magnetic reversals, such as the Blake event 120,000 years theory adds an intriguing piece to the puzzle, but it's far from did a shift in Earth's magnetic field doom the Neanderthals?Probably not. While the Laschamp event may have had some environmental impact, there's no strong evidence that it caused Neanderthal extinction . The theory suggests that the disappearance of Neanderthals was likely due to a mix of climate, biology, and human interaction.
Time of India
22-06-2025
- Science
- Time of India
They survived ice ages and hunted mammoths; so why did the Neanderthals suddenly disappear? Now a physicist blames something in the sky
Neanderthals have long puzzled scientists. These ancient relatives of modern humans thrived across Europe and parts of Asia for hundreds of thousands of years. But around 40,000 years ago, they disappeared, just as Homo sapiens spread across the same regions. What really caused their extinction remains one of human evolution's biggest mysteries. Now, a new and unusual theory suggests that space weather, not climate, competition, or disease, may have played a decisive role. A recent study by Dr. Agnit Mukhopadhyay, a space physicist from the University of Michigan , proposes that a powerful cosmic event known as the Laschamp excursion might have played a part in the Neanderthals' decline. The findings were published in the journal Science Advances. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like If You Eat Ginger Everyday for 1 Month This is What Happens Tips and Tricks Undo The Laschamp event occurred about 41,000 years ago, when the Earth's magnetic poles temporarily flipped. During this brief reversal, the planet's magnetic field, which normally protects us from cosmic radiation, dramatically weakened for several centuries. Mukhopadhyay argues that this weakening may have exposed the Earth's surface to much higher levels of ultraviolet (UV) and cosmic radiation, particularly in some parts of the world. Live Events Radiation as a Hidden Killer? The core of the hypothesis is that Neanderthals, already living in small, isolated populations, may have been more vulnerable to this radiation than Homo sapiens. The study claims that Homo sapiens had tighter clothing, used red ochre as UV protection, and took shelter in caves helping them survive the radiation. Neanderthals, in contrast, might have lacked these protections. Computer simulations in the study even show that auroras, a sign of increased solar activity, might have been visible across much of the world during this time, proof, the author argues, of the heightened radiation environment. While the theory is bold and imaginative, many experts are skeptical. Researchers José-Miguel Tejero and Montserrat Sanz Borràs, writing for The Conversation, point out that the idea rests on shaky archaeological evidence. For example, it assumes that Neanderthals didn't wear fitted clothing. While it's true that no sewing needles have been found at Neanderthal sites, there is clear evidence that they processed animal hides and likely wore functional garments using other techniques, such as tying hides with leather cords or splinters. In fact, genetic studies of lice suggest that humans, possibly including Neanderthals, were already wearing clothes over 200,000 years ago. The absence of needles doesn't prove the absence of clothes. The study also claims that Homo sapiens used red ochre as sunblock. While experiments show that ochre can somewhat block UV rays, this claim is also disputed. Ochre was widely used by both Neanderthals and modern humans, often for symbolic or cosmetic reasons. There is no solid evidence that either group used it primarily for sun protection. Neanderthals are known to have used ochre for over 100,000 years. In one example, a painted scallop shell found in a Neanderthal cave in Spain shows their symbolic use of pigments long before Homo sapiens arrived in Europe. Most scientists believe that multiple factors caused the Neanderthals' disappearance. These include, interbreeding with Homo sapiens (evident in modern DNA), smaller populations that were more vulnerable to decline, limited long-range hunting tools, unlike the projectile weapons used by sapiens, Changing climate, and possibly, competition for resources. In this broader context, Mukhopadhyay's theory appears too narrow. Critics note that there is no archaeological evidence of a sudden, global collapse of Neanderthal populations tied to the Laschamp event. If radiation were such a major factor, it would have also harmed Homo sapiens populations living outside caves in sunny Africa, which doesn't seem to have happened. A Caution Against Oversimplification The Neanderthal story is complex. These early humans were not primitive brutes. They developed tools, built shelters, made symbolic objects, and survived in extreme climates for hundreds of thousands of years. They even lived through earlier magnetic reversals, such as the Blake event 120,000 years ago. Mukhopadhyay's theory adds an intriguing piece to the puzzle, but it's far from conclusive. So, did a shift in Earth's magnetic field doom the Neanderthals? Probably not. While the Laschamp event may have had some environmental impact, there's no strong evidence that it caused Neanderthal extinction . The theory suggests that the disappearance of Neanderthals was likely due to a mix of climate, biology, and human interaction.
Yahoo
19-06-2025
- Science
- Yahoo
Neanderthal extinction: a space physicist reopens the debate
Neanderthals have long been the subject of intense scientific debate. This is largely because we still lack clear answers to some of the big questions about their existence and supposed disappearance. One of the latest developments is a recent study from the University of Michigan, published in the journal Science Advances. It proposes that Neanderthals went extinct for astrophysical reasons. The work was led by Agnit Mukhopadhyay, an expert in space physics, a discipline that studies natural plasmas, especially those found within our own solar system. Plasma is the state of matter that dominates the universe: the Sun and stars are huge balls of plasma, as are the northern lights. Mukhopadhyay's research suggests that a shift in the Earth's magnetic poles around 41,000 years ago, known as the Laschamp event, may have contributed to the extinction of Neanderthals. According to his work, the extreme weakening of the Earth's magnetic field during that event allowed for greater penetration of cosmic and ultraviolet radiation. This would have generated more aggressive environmental conditions that Neanderthals could not withstand, giving our own species, Homo sapiens, an edge. In this context, sapiens would have had an advantage over Neanderthals thanks to their presumed use of close-fitting clothing, ochre – a mineral with protective properties against the sun – and taking shelter in caves. Caves which, by the way, on numerous occasions were inhabited by both Neanderthals and our own species. The hypothesis is interesting, and is based on innovative three-dimensional models of the Earth's geospatial system during this period. However, as with many hypotheses that attempt to explain complex phenomena on the basis of a single variable, its scope and some of the assumptions on which it is based need to be examined more closely. One of the pillars of this hypothesis is that Neanderthals did not wear tight-fitting clothing, and would therefore have been more exposed to the harmful effects of solar radiation. It is true that sewing needles have not been definitvely linked to Neanderthals. The first needles documented in Eurasia are associated with either Denisovan or sapiens populations around 50,000 years ago, and in western Europe they did not appear until around 23,000 years ago. But this does not mean that Neanderthals did not wear clothing. In fact, the Homo sapiens who lived during episodes of extreme cold (such as the Heinrich 4 event, which occurred some 39,600 years ago) did not have sewing needles either, but they did have enough technology to make garments, and possibly tents and footwear. There is ample archaeological evidence of Neanderthals processing hides, such as the systematic use of scrapers and other tools associated with the tanning process. However, the use of fur or clothing has much older origins. In fact, the genetic study of lice has revealed that humans were already wearing clothing at least 200,000 years ago. Furthermore, in cold environments such as those they inhabited in Europe, it would have been unfeasible to survive without some form of body protection. Even if they did not have needles, it is very plausible that they used alternative systems such as ligatures or bone splinters to adapt animal hides to the body. The absence of needles should not be confused with the absence of functional clothing. The study also highlights the use of ochre by Homo sapiens, which it says offered protection against solar radiation. Although experiments have been carried out to demonstrate certain blocking capacities of ochre against ultraviolet (UV) rays, its use by human populations is not limited to a single group. In fact, evidence of pigment use during the same period has been found in Africa, the Near East and the Iberian Peninsula, and among different human lineages. The use of ochre has been documented in Neanderthal contexts for more than 100,000 years, both in Europe and in the Levant. Its application may have had multiple purposes: symbolic, therapeutic, cosmetic, healing, and even an insect repellent. There are no solid grounds for claiming that its use for protective purposes was exclusive to Homo sapiens, especially when both species shared spaces and technologies for millennia. Nor can we be sure that it was used as a protective sunscreen. Leer más: One of the most significant factors may have been the marked difference in population size. There were fewer Neanderthals, meaning they would have been assimilated by the much more numerous populations of Homo sapiens. This assimilation is reflected in the DNA of current populations, suggesting that, rather than becoming extinct, Neanderthals were absorbed into the evolutionary process. Technology also played a part– as far as we know, Neanderthals did not use hunting weapons at a distance. The invention and use of projectiles associated with hunting activities – first in stone and later in hard animal materials – appear to be an innovation specific to Homo sapiens. Their development may have given them an adaptive advantage in open environments, and a greater capacity to exploit different prey and environments. Leer más: Associating the Neanderthal 'extinction' to their supposed failure to adapt to increased solar radiation during the Laschamp excursion oversimplifies a phenomenon that remains the subject of heated debate. Put simply, the archaeological record does not support Mukhopadhyay's hypothesis. There is no evidence of an abrupt demographic collapse coinciding with this geomagnetic event, nor of a widespread catastrophic impact on other human or animal species. Moreover, if solar radiation had been such a determining factor, one would expect high mortality also among populations of sapiens that did not wear tight clothing or live in caves (in warm regions of Africa, for instance). As far as we know, this did not happen. When trying to explain the disappearance of Neanderthals, it is vital that we integrate multiple lines of archaeological, paleoanthropological and genetic evidence. These humans were not simply victims of their own technological clumsiness or of a hostile environment that they failed to cope with. They were an adaptive and culturally complex species that, for more than 300,000 years, survived multiple climatic changes – including other geomagnetic shifts such as the Blake event, which occurred about 120,000 years ago. Neanderthals developed sophisticated tools, dominated vast territories and shared many more traits with us than was assumed for decades. So did the magnetic reversal of the Earth's magnetic poles wipe out the Neanderthals? The answer is: probably not. Este artículo fue publicado originalmente en The Conversation, un sitio de noticias sin fines de lucro dedicado a compartir ideas de expertos académicos. Lee mas: Neanderthals: the oldest art in the world wasn't made by Homo sapiens Modern human DNA contains bits from all over the Neanderthal genome – except the Y chromosome. What happened? How Neanderthal language differed from modern human – they probably didn't use metaphors Las personas firmantes no son asalariadas, ni consultoras, ni poseen acciones, ni reciben financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y han declarado carecer de vínculos relevantes más allá del cargo académico citado anteriormente.
