Latest news with #evolution
BBC News
14 hours ago
- Health
- BBC News
Why your fingers wrinkle in water (and what it can reveal about your health)
The skin on our fingertips and toes shrivels like prunes when soaked for a few minutes in water. But is this an adaptation that occurred to help us in our evolutionary past? And what can it reveal about your health today? Spend more than a few minutes soaking in a bath or paddling around a swimming pool and your fingers will undergo a dramatic transformation. Where there were once delicate whorls of lightly ridged epidermis, engorged folds of ugly pruned skin will now be found. And according to a recently published study, this striking change is worth a closer inspection – each time your fingertips pucker in this way, the wrinkles create the same pattern. It is the latest discovery about a phenomenon that has occupied the thoughts and work of scientists for decades. Bafflingly, only the skin on our fingers and toes wrinkles when immersed in water. Other body parts such as our forearms, torso, legs and face remain no more crinkled than they were before being submerged. Most researchers in the field have puzzled over what causes this puckering in the first place, but more recently the question of why and what purpose it may serve, has attracted their attention. Perhaps more intriguing still, however, is what our shrivelled fingers can reveal about our own health. Scientists have discovered changes in how our fingers wrinkle can point to diseases including type 2 diabetes, cystic fibrosis, nerve injuries and even cardiovascular problems. What causes our fingers to wrinkle It takes around 3.5 minutes in warm water – 40C (104F) is considered the optimal temperature – for your fingertips to begin wrinkling, while in cooler temperatures of about 20C (68F) it can take up to 10 minutes. Most studies have found it takes around 30 minutes of soaking time to reach maximum wrinklage, however. (Interestingly, recent research has shown that soaking your hands in warm vinegar can make your skin wrinkle far faster – in around just four minutes.) Fingertip wrinkling was commonly thought to be a passive response where the upper layers of the skin swelled as water flooded into the cells via a process known as osmosis – where water molecules move across a membrane to equalise the concentration of the solutions on either side. But as long ago as 1935, scientists have suspected there is more to the process than this. Doctors studying patients with injuries that had severed the median nerve – one of the main nerves that run down the arm to the hand – found that their fingers did not wrinkle. Among its many roles, the median nerve helps to control so-called sympathetic activities such as sweating and the constriction of blood vessels. Their discovery suggested that the water-induced wrinkling of fingertips was in fact controlled by the nervous system. Later studies by doctors in the 1970s provided further evidence of this, and they proposed using the immersion of the hands in water as a simple bedside test to assess nerve damage that might affect the regulation of unconscious processes such as blood flow. Then in 2003, neurologists Einar Wilder-Smith and Adeline Chow, who were working at the National University Hospital in Singapore at the time, took measurements of blood circulation in the hands of volunteers as they soaked them in water. They found that as the skin on the volunteers' fingertips began to wrinkle, there was a significant drop in blood flow in the fingers. When they applied a local anesthetic cream that caused the blood vessels in the fingers of healthy volunteers to temporarily constrict, they found it produced similar levels of wrinkling as water immersion. "It makes sense when you look at your fingers when they go wrinkly," says Nick Davis, a neuroscientist and psychologist at Manchester Metropolitan University, who has studied fingertip wrinkling. "The finger pads go pale and that is because the blood supply is being constricted away from the surface." Wilder-Smith and his colleagues proposed that when our hands are immersed in water, the sweat ducts in our fingers open up to allow water in, which leads to an imbalance in the salts in our skin. This change in the salt balance triggers the firing of nerve fibres in the fingers, leading to the blood vessels around the sweat ducts to constrict. This in turn causes a loss of volume in the fleshy area of the fingertip, which pulls the overlying skin downwards so that it distorts into wrinkles. The pattern of the wrinkles depends on the way the outermost layer of skin – the epidermis – is anchored to the layers beneath it. More like this: There have also been suggestions that the outer layers of skin may also swell a little to enhance the wrinkling. By osmosis alone, however, our skin would need to swell by 20% to achieve the wrinkles we see in our fingers, which would leave them hideously enlarged. But when the upper layers of skin swell slightly and the lower levels shrink at the same time, the wrinkling becomes pronounced far sooner, says Pablo Saez Viñas, a biomechanical engineer at the Technical University of Catalonia, who has used computer modelling to examine the mechanism. "You need both to have normal levels of wrinkles," he says. "If you don't have that neurological response, which happens in some individuals, wrinkles are inhibited." But if wrinkling is controlled by our nerves, it means our bodies are actively reacting to being in water. "That means it is happening for a reason," says Davis. "And that means it could be giving us an advantage." Why did our fingers evolve to wrinkle in water? It was a question from one of his children during a bath about why their fingers had gone wrinkly that recently led Davis to dig into what this advantage could be. With the help of 500 volunteers who visited the Science Museum in London during 2020, Davis measured how much force they needed to use to grip a plastic object. Perhaps unsurprisingly, those with dry, unwrinkled hands needed to use less force than people whose hands were wet – so their grip on the object was better. But when they submerged their hands in a water bath for a few minutes to turn their hands wrinkly, the grip force fell between the two even though their hands were still wet. "The results were amazingly clear," says Davis. "The wrinkling increased the amount of friction between the fingers and the object. What is particularly interesting is that our fingers are sensitive to this change in the surface friction and we use this information to apply less force to grip an object securely." The object that Davis' volunteers were gripping weighed less than a couple of coins, so the amount of grip required was small. But when performing more arduous tasks in a wet environment, this difference in friction could become more important. "If you don't have to squeeze as hard to grip something, the muscles in your hands get less tired and so you can do it for longer," he says. His findings match those by other researchers who have found that the wrinkling of our fingertips makes it easier for us to handle wet objects. In 2013, a team of neuroscientists at Newcastle University in the UK asked volunteers to transfer glass marbles of varying sizes and fishing weights from one container to another. In one case the objects were dry, and in the other they were at the bottom of a container filled with water. It took 17% longer for the participants to transfer the submerged objects with unwrinkled fingers than when they were dry. But when their fingers were wrinkled, they could transfer the submerged marbles and weights 12% quicker than when their fingers were wet and unwrinkled. Interestingly, there was no difference in transferring the dry objects with wrinkled or unwrinkled fingers. There are other baffling mysteries – women take longer to develop wrinkles than men do Some scientists have suggested that the wrinkles on our fingertips and toes may act like rain treads on tyres or the soles of shoes. The channels produced by the wrinkles help to squeeze water away from the point of contact between the fingers and an object. This suggests that humans may have evolved fingertip and toe wrinkling at some point in our past to help us grip wet objects and surfaces. "Since it seems to give better grip under water, I would assume that it has to do with either locomotion in very wet conditions or potentially with manipulating objects under water," says Tom Smulders, an evolutionary neuroscientist at Newcastle University who led the 2013 study. It could have given our ancestors a key advantage when it came to walking over wet rocks or gripping branches, for example. Alternatively, it could have helped us when catching or foraging for food such as shellfish. "The latter would imply it is unique to humans, whereas if it's the former, we would expect it to happen in other primates as well," says Smulders. Finger wrinkling has yet to be observed in our closest relatives in the primate world such as chimpanzees, but the fingers of Japanese macaque monkeys, which are known to bath for long periods in hot water, have been seen to also wrinkle after they have been submerged in water. But the lack of evidence in other primates does not mean it doesn't happen, it may simply be because no-one has looked closely enough yet, says Smulders. "We don't know the answer to this question yet." There are some other interesting clues about when this adaptation may have appeared in our species. Fingertip wrinkling is less pronounced in saltwater and takes longer than it does in freshwater. This is probably because the salt gradient between the skin and surrounding environment is lower in saltwater, and so the salt imbalance that triggers the nerve fibres is less dramatic. So, it could be an adaptation that helped our ancestors live in freshwater environments rather than along coastlines. But there are no firm answers, and some believe it could just be a coincidental physiological response with no adaptive function. What can we learn from the wrinkles? Strangely there are other baffling mysteries – women take longer to develop wrinkles than men do, for example. And why exactly does our skin return to its normal state – normally after 10-20 minutes – if there is no clear disadvantage to our grip on dry objects of having wrinkly fingertips? Surely if having wrinkly fingers can improve our grip in the wet, but not harm it when dry, why would our fingertips not be permanently wrinkly? One reason for that could be the change in sensation the wrinkling also causes. Our fingertips are packed with nerves, and the pruning of our skin changes the way we feel things we touch (although one study has shown it does not affect our ability to discriminate between objects based on touch). "Some people have a real aversion to it because picking something up with wrinkly fingers feels weird," says Davis. "It could be because the balance of skin receptors have changed position, but there could be a psychological dimension too. It would be fun to investigate why. There could be other things we can do less well with wrinkly fingers." But the wrinkling of our fingers and toes in water can reveal key information about our health in surprising ways too. Wrinkles take longer to form in people with skin conditions like psoriasis and vitiligo, for example. Patients with cystic fibrosis experience excessive wrinkling of their palms as well as their fingers, and this has even been noticed in people who are genetic carriers of the disease. Patients suffering from type 2 diabetes also sometimes show markedly decreased levels of skin wrinkling when their hands are placed in water. Similarly reduced wrinkling has been seen in people who have suffered heart failure, perhaps due to some disruption in the control of their cardiovascular system. Unsymmetrical wrinkling of the fingers – where one hand wrinkles less than the other despite the same immersion time – has even been suggested as an early sign of Parkinson's disease as it indicates the sympathetic nervous system is not functioning correctly on one side of the body. So, while the question of why our fingers and toes began wrinkling in water in the first place remains open, our pruney digits are proving useful to doctors in other surprising ways. * This article was originally published on 21 June 2022. It was updated on 19 June 2025 to include details of a new study on the repeatability of wrinkle patterns on wet fingers. -- If you liked this story, sign up for The Essential List newsletter – a handpicked selection of features, videos and can't-miss news, delivered to your inbox twice a week. For more science, technology, environment and health stories from the BBC, follow us on Facebook, X and Instagram.
Yahoo
a day ago
- Science
- Yahoo
‘Dragon Man' DNA revelation puts a face to a mysterious group of ancient humans
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. An enigmatic skull recovered from the bottom of a well in northeastern China in 2018 sparked intrigue when it didn't match any previously known species of prehistoric human. Now, scientists say they have found evidence of where the fossil fits, and it could be a key piece in another cryptic evolutionary puzzle. After several failed attempts, the researchers managed to extract genetic material from the fossilized cranium — nicknamed Dragon Man — linking it to an enigmatic group of early humans known as Denisovans. A dozen or so Denisovan fossilized bone fragments had previously been found and identified using ancient DNA. But the specimens' small size offered little idea of what this shadowy population of ancient hominins looked like, and the group has never been assigned an official scientific name. Scientists typically consider skulls, with telltale bumps and ridges, the best type of fossilized remains to understand the form or appearance of an extinct hominin species. The new findings, if confirmed, could effectively put a face to the Denisovan name. 'I really feel that we have cleared up some of the mystery surrounding this population,' said Qiaomei Fu, a professor at the Institute of Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences in Beijing, and lead author of the new research. 'After 15 years, we know the first Denisovan skull.' Denisovans were first discovered in 2010 by a team that included Fu — who was then a young researcher at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany — from ancient DNA contained in a pinkie fossil found in Denisova Cave in the Altai Mountains of Russia. Additional remains unearthed in the cave, from which the group gets its name, and elsewhere in Asia continue to add to the still-incomplete picture. The new research, described in two scientific papers published Wednesday, is 'definitely going to be among, if not the, biggest paleoanthropology papers of the year,' and will spur debate in the field 'for quite some time,' said Ryan McRae, a paleoanthropologist at the Smithsonian National Museum of Natural History in Washington, DC, who was not involved in the studies. The findings could help fill in gaps about a time when Homo sapiens weren't the only humans roaming the planet — and teach scientists more about modern humans. Our species once coexisted for tens of thousands of years and interbred with both Denisovans and Neanderthals before the two went extinct. Most humans today carry a genetic legacy of those ancient encounters. Neanderthal fossils have been the subject of study for than a century, but scant details are known about our mysterious Denisovan cousins, and a skull fossil can reveal a great deal. A laborer in the city of Harbin in northeastern China discovered the Dragon Man skull in 1933. The man, who was constructing a bridge over the Songhua River when that part of the country was under Japanese occupation, took home the specimen and stored it at the bottom of a well for safekeeping. The man never retrieved his treasure, and the cranium, with one tooth still attached in the upper jaw, remained unknown to science for decades until his relatives learned about it before his death. His family donated the fossil to Hebei GEO University, and researchers first described it in a set of studies published in 2021 that found the skull to be at least 146,000 years old. The researchers argued that the fossil merited a new species name given the unique nature of the skull, naming it Homo longi — which is derived from Heilongjiang, or Black Dragon River, the province where the cranium was found. Some experts at the time hypothesized that the skull might be Denisovan, while others have lumped the cranium in with a cache of difficult-to-classify fossils found in China, resulting in intense debate and making molecular data from the fossil particularly valuable. Given the skull's age and backstory, Fu said she knew it would be challenging to extract ancient DNA from the fossil to better understand where it fit in the human family tree. 'There are only bones from 4 sites over 100,000 (years old) in the world that have ancient DNA,' she noted via email. Fu and her colleagues attempted to retrieve ancient DNA from six samples taken from Dragon Man's surviving tooth and the cranium's petrous bone, a dense piece at the base of the skull that's often a rich source of DNA in fossils, without success. The team also tried to retrieve genetic material from the skull's dental calculus — the gunk left on teeth that can over time form a hard layer and preserve DNA from the mouth. From this process, the researchers managed to recover mitochondrial DNA, which is less detailed than nuclear DNA but revealed a link between the sample and the known Denisovan genome, according to one new paper published in the journal Cell. 'Mitochondrial DNA is only a small portion of the total genome but can tell us a lot. The limitations lie in its relatively small size compared to nuclear DNA and in the fact that it is only inherited from the matrilineal side, not both biological parents,' McRae said. 'Therefore, without nuclear DNA a case could be made that this individual is a hybrid with a Denisovan mother, but I think that scenario is rather less likely than this fossil belonging to a full Denisovan,' he added. The team additionally recovered protein fragments from the petrous bone samples, the analysis of which also suggested the Dragon Man skull belonged to a Denisovan population, according to a separate paper published Wednesday in the journal Science. Together, 'these papers increase the impact of establishing the Harbin cranium as a Denisovan,' Fu said. The molecular data provided by the two papers is potentially very important, said anthropologist Chris Stringer, research leader in human origins at London's Natural History Museum. 'I have been collaborating with Chinese scientists on new morphological analyses of human fossils, including Harbin,' he said. 'Combined with our studies, this work makes it increasingly likely that Harbin is the most complete fossil of a Denisovan found so far.' However, Xijun Ni, a professor at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing who, along with Stringer, worked on the initial Dragon Man research but not the latest studies, said that he is cautious about the outcome of the two papers because some of the DNA extraction methods used were 'experimental.' Ni also said he finds it strange that DNA was obtained from surface dental calculus but not inside the tooth and petrous bone, given that the calculus appeared to be more exposed to potential contamination. Nonetheless, he added that he thinks it is likely the skull and other fossils identified as Denisovan are from the same human species. The goal in using a new extraction approach was to recover as much genetic material as possible, Fu explained, adding that the dense crystalline structure of dental calculus may help prevent the host DNA from being lost. The protein signatures Fu and her team recovered indicated 'a Denisovan attribution, with other attributions very unlikely,' said Frido Welker, an associate professor of biomolecular paleoanthropology at the University of Copenhagen's Globe Institute in Denmark. Welker has recovered Denisovan proteins from other candidate fossils but was not involved in this research. 'With the Harbin cranium now linked to Denisovans based on molecular evidence, a larger portion of the hominin fossil record can be compared reliably to a known Denisovan specimen based on morphology,' he said. With the Dragon Man skull now linked to Denisovans based on molecular evidence, it will be easier for paleoanthropologists to classify other potential Denisovan remains from China and elsewhere. McRae, Ni and Stringer all said they thought it was likely that Homo longi would become the official species name for Denisovans, although other names have been proposed. 'Renaming the entire suite of Denisovan evidence as Homo longi is a bit of a step, but one that has good standing since the scientific name Homo longi was technically the first to be, now, tied to Denisovan fossils,' McRae said. However, he added that he doubts the informal name of Denisovan is going anywhere anytime soon, suggesting it might become shorthand for the species, as Neanderthal is to Homo neanderthalensis. The findings also make it possible to say a little more about what Denisovans might have looked like, assuming the Dragon Man skull belonged to a typical individual. According to McRae, the ancient human would have had very strong brow ridges, brains 'on par in size to Neanderthals and modern humans' but larger teeth than both cousins. Overall, Denisovans would have had a blocky and robust-looking appearance. 'As with the famous image of a Neanderthal dressed in modern attire, they would most likely still be recognizable as 'human,'' McRae said. 'They are still our more mysterious cousin, just slightly less so than before,' he added. 'There is still a lot of work to be done to figure out exactly who the Denisovans were and how they are related to us and other hominins.'
Yahoo
2 days ago
- Science
- Yahoo
A skull found in a well defied classification. Now it could help unravel an evolutionary mystery
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. An enigmatic skull recovered from the bottom of a well in northeastern China in 2018 sparked intrigue when it didn't match any previously known species of prehistoric human. Now, scientists say they have found evidence of where the fossil fits, and it could be a key piece in another cryptic evolutionary puzzle. After several failed attempts, the researchers managed to extract genetic material from the fossilized cranium — nicknamed Dragon Man — linking it to an enigmatic group of early humans known as Denisovans. A dozen or so Denisovan fossilized bone fragments had previously been found and identified using ancient DNA. But the specimens' small size offered little idea of what this shadowy population of ancient hominins looked like, and the group has never been assigned an official scientific name. Scientists typically consider skulls, with telltale bumps and ridges, the best type of fossilized remains to understand the form or appearance of an extinct hominin species. The new findings, if confirmed, could effectively put a face to the Denisovan name. 'I really feel that we have cleared up some of the mystery surrounding this population,' said Qiaomei Fu, a professor at the Institute of Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences in Beijing, and lead author of the new research. 'After 15 years, we know the first Denisovan skull.' Denisovans were first discovered in 2010 by a team that included Fu — who was then a young researcher at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany — from ancient DNA contained in a pinkie fossil found in Denisova Cave in the Altai Mountains of Russia. Additional remains unearthed in the cave, from which the group gets its name, and elsewhere in Asia continue to add to the still-incomplete picture. The new research, described in two scientific papers published Wednesday, is 'definitely going to be among, if not the, biggest paleoanthropology papers of the year,' and will spur debate in the field 'for quite some time,' said Ryan McRae, a paleoanthropologist at the Smithsonian National Museum of Natural History in Washington, DC, who was not involved in the studies. The findings could help fill in gaps about a time when Homo sapiens weren't the only humans roaming the planet — and teach scientists more about modern humans. Our species once coexisted for tens of thousands of years and interbred with both Denisovans and Neanderthals before the two went extinct. Most humans today carry a genetic legacy of those ancient encounters. Neanderthal fossils have been the subject of study for than a century, but scant details are known about our mysterious Denisovan cousins, and a skull fossil can reveal a great deal. A laborer in the city of Harbin in northeastern China discovered the Dragon Man skull in 1933. The man, who was constructing a bridge over the Songhua River when that part of the country was under Japanese occupation, took home the specimen and stored it at the bottom of a well for safekeeping. The man never retrieved his treasure, and the cranium, with one tooth still attached in the upper jaw, remained unknown to science for decades until his relatives learned about it before his death. His family donated the fossil to Hebei GEO University, and researchers first described it in a set of studies published in 2021 that found the skull to be at least 146,000 years old. The researchers argued that the fossil merited a new species name given the unique nature of the skull, naming it Homo longi — which is derived from Heilongjiang, or Black Dragon River, the province where the cranium was found. Some experts at the time hypothesized that the skull might be Denisovan, while others have lumped the cranium in with a cache of difficult-to-classify fossils found in China, resulting in intense debate and making molecular data from the fossil particularly valuable. Given the skull's age and backstory, Fu said she knew it would be challenging to extract ancient DNA from the fossil to better understand where it fit in the human family tree. 'There are only bones from 4 sites over 100,000 (years old) in the world that have ancient DNA,' she noted via email. Fu and her colleagues attempted to retrieve ancient DNA from six samples taken from Dragon Man's surviving tooth and the cranium's petrous bone, a dense piece at the base of the skull that's often a rich source of DNA in fossils, without success. The team also tried to retrieve genetic material from the skull's dental calculus — the gunk left on teeth that can over time form a hard layer and preserve DNA from the mouth. From this process, the researchers managed to recover mitochondrial DNA, which is less detailed than nuclear DNA but revealed a link between the sample and the known Denisovan genome, according to one new paper published in the journal Cell. 'Mitochondrial DNA is only a small portion of the total genome but can tell us a lot. The limitations lie in its relatively small size compared to nuclear DNA and in the fact that it is only inherited from the matrilineal side, not both biological parents,' McRae said. 'Therefore, without nuclear DNA a case could be made that this individual is a hybrid with a Denisovan mother, but I think that scenario is rather less likely than this fossil belonging to a full Denisovan,' he added. The team additionally recovered protein fragments from the petrous bone samples, the analysis of which also suggested the Dragon Man skull belonged to a Denisovan population, according to a separate paper published Wednesday in the journal Science. Together, 'these papers increase the impact of establishing the Harbin cranium as a Denisovan,' Fu said. The molecular data provided by the two papers is potentially very important, said anthropologist Chris Stringer, research leader in human origins at London's Natural History Museum. 'I have been collaborating with Chinese scientists on new morphological analyses of human fossils, including Harbin,' he said. 'Combined with our studies, this work makes it increasingly likely that Harbin is the most complete fossil of a Denisovan found so far.' However, Xijun Ni, a professor at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing who, along with Stringer, worked on the initial Dragon Man research but not the latest studies, said that he is cautious about the outcome of the two papers because some of the DNA extraction methods used were 'experimental.' Ni also said he finds it strange that DNA was obtained from surface dental calculus but not inside the tooth and petrous bone, given that the calculus appeared to be more exposed to potential contamination. Nonetheless, he added that he thinks it is likely the skull and other fossils identified as Denisovan are from the same human species. The goal in using a new extraction approach was to recover as much genetic material as possible, Fu explained, adding that the dense crystalline structure of dental calculus may help prevent the host DNA from being lost. The protein signatures Fu and her team recovered indicated 'a Denisovan attribution, with other attributions very unlikely,' said Frido Welker, an associate professor of biomolecular paleoanthropology at the University of Copenhagen's Globe Institute in Denmark. Welker has recovered Denisovan proteins from other candidate fossils but was not involved in this research. 'With the Harbin cranium now linked to Denisovans based on molecular evidence, a larger portion of the hominin fossil record can be compared reliably to a known Denisovan specimen based on morphology,' he said. With the Dragon Man skull now linked to Denisovans based on molecular evidence, it will be easier for paleoanthropologists to classify other potential Denisovan remains from China and elsewhere. McRae, Ni and Stringer all said they thought it was likely that Homo longi would become the official species name for Denisovans, although other names have been proposed. 'Renaming the entire suite of Denisovan evidence as Homo longi is a bit of a step, but one that has good standing since the scientific name Homo longi was technically the first to be, now, tied to Denisovan fossils,' McRae said. However, he added that he doubts the informal name of Denisovan is going anywhere anytime soon, suggesting it might become shorthand for the species, as Neanderthal is to Homo neanderthalensis. The findings also make it possible to say a little more about what Denisovans might have looked like, assuming the Dragon Man skull belonged to a typical individual. According to McRae, the ancient human would have had very strong brow ridges, brains 'on par in size to Neanderthals and modern humans' but larger teeth than both cousins. Overall, Denisovans would have had a blocky and robust-looking appearance. 'As with the famous image of a Neanderthal dressed in modern attire, they would most likely still be recognizable as 'human,'' McRae said. 'They are still our more mysterious cousin, just slightly less so than before,' he added. 'There is still a lot of work to be done to figure out exactly who the Denisovans were and how they are related to us and other hominins.'
BBC News
2 days ago
- Science
- BBC News
Glowing, biofluorescent fish originated over a hundred million years ago
Did you know that some fish can glow with different colours?This special ability is called biofluorescence and scientists have now found it dates back over a hundred million years. Two new studies led by scientists at the American Museum of Natural History also found that there are more colours of biofluorescence than previously thought - and more species with this power. The authors also suggest this huge variation of colours and patterns could mean the fish are using the glow to communicate with each other. Biofluorescence is where a living organism can absorb light before letting it out again. The result is the creatures seem to glow with different colours and even patterns. It is different to bioluminescence which is when the creatures create the light inside themselves and so can glow in total darkness. The researchers produced a list of 459 biofluorescent species, including 48 species that were not previously known to be also estimated the biofluorescence dated back about 112 million years, with the first instance happening in team also found that fish species that live in or around coral reefs evolve biofluorescence faster than those that live outside of the reef. Most of the species studied were associated with coral reefs. The researchers found there was a sharp increase in glowing species after the dinosaurs became extinct 66 million years was also when there was a rise of modern coral-dominated reefs which the study authors say could explain the sudden surge of the second study, published in PLOS One, the scientists looked at fish they already knew were biofluorescent under special researchers were surprised by the range of colours with some species giving out several colours and patterns.
Forbes
6 days ago
- Science
- Forbes
Meet The Bird That Soars Higher Than Any Other. Hint: It Flies Higher Than Commercial Airplanes
Most birds don't fly that high in the air. In fact, some birds – such as the emu or the cassowary – don't fly at all. They have wings, but only in the 'vestigial' sense, meaning that their wings are non-functional remnants of their flying ancestors. Evolution went even further in New Zealand's moas, which were completely wingless. Yet there are some flight-capable bird species with a knack for soaring really high in the air. While this may sound like a matter of choice, it's actually quite complicated. Flying at high altitudes requires birds to be more efficient in their movement and energy production. For instance, research published in the Journal of Experimental Biology suggests that high-altitude birds have developed unique specializations such as more effective breathing patterns, larger lungs and blood with a higher oxygen affinity. These adaptations, according to the research, allows birds to 'improve the uptake, circulation and efficient utilization of oxygen during high-altitude hypoxia.' High-flying birds also tend to have larger wings than their low-flying cousins, presumably to allow the birds to soar without expending as much energy. Research has identified a handful of bird species that are known to soar at altitudes of 20,000+ feet – the most notable and highest soarer being the Ruppell's griffon. Here is more detail on the record-setting, 'Chuck Yeager's' of the bird world. This African vulture holds the record for the highest known bird flight. In fact, a Ruppell's griffon collided with a commercial aircraft over western Africa at an altitude of 37,000 feet, higher than the cruising height of most airliners. The species is uniquely adapted to extreme altitudes, with hemoglobin that binds oxygen more effectively than that of almost any other bird. These vultures rely on powerful soaring techniques and can cover vast distances in search of carrion, making use of rising thermal currents to stay aloft with minimal energy expenditure. This bird is known for its grueling migrations over the Himalayas, including Mount Everest. Bar-headed geese have been recorded flying at elevations above 27,000 feet during their seasonal journeys between Central Asia and the Indian subcontinent. To cope with the thin air, they possess a high lung capacity and their muscles are particularly efficient at using oxygen. These physiological traits allow them to flap continuously, rather than just soar, even in oxygen-starved environments. The alpine chough, a member of the crow family, lives in mountainous regions across Europe, North Africa and Asia. Though not migratory in the same way as the bar-headed goose, this species regularly forages and nests at high altitudes. Observations have documented Alpine choughs flying at over 25,000 feet. Their strong, curved wings and acrobatic flight style allow them to navigate rugged terrain with ease, making the most of updrafts and wind currents that sweep over alpine cliffs. Known for their distinctive trumpet-like calls, whooper swans are powerful, long-distance migrants. These swans have been spotted by pilots at heights of up to 25,000 feet during their transcontinental migrations between Europe and Asia. Despite their large size, their strong wings and streamlined bodies help them maintain high-altitude flight over long distances. They often travel in V-shaped formations that improve aerodynamic efficiency and conserve energy among the flock. The steppe eagle is a bird of prey that breeds in the open plains and steppes of Central Asia. These eagles are skilled soarers, often riding thermal updrafts to reach extreme heights. Their broad wings and keen eyesight make them efficient hunters and scavengers, capable of spotting prey from great distances. Their long-distance migratory routes take them across mountainous regions where such high-altitude flights are essential. Also known as the bearded vulture, the lammergeier is a striking bird that thrives in mountainous regions from Europe to the Himalayas. It has been recorded flying at heights of up to 24,000 feet, gliding on thermals. Unique among vultures, lammergeiers primarily feed on bone marrow, often dropping large bones from great heights onto rocks to crack them open. Their adaptations for high-altitude flight include long, narrow wings and a lightweight frame, enabling them to maneuver with precision in thin air. Despite their delicate appearance, demoiselle cranes are among the toughest migratory birds in the world. Each year, they make a perilous journey over the Himalayas to reach their wintering grounds in India. Flying at altitudes up to 24,000 feet, they endure fierce winds, cold temperatures and low oxygen levels. These cranes are known for their resilience and strong familial bonds, often migrating in flocks that include young birds guided by their experienced elders. Are you an animal lover who owns a pet, perhaps even a pet bird? Take the science-backed Pet Personality Test to know how well you know your little friend.
