73 Evolution News Articles
for August 2018
Click on the links below to get the full story from its source
8-19-18 The end of nighttime
Light pollution is often characterized as a soft issue in environmentalism. This perception needs to change. Light at night constitutes a massive assault on the ecology of the planet, including us. It also has indirect impacts because, while 20 percent of electricity is used for lighting worldwide, at least 30 percent of that light is wasted. Wasted light serves no purpose at all, and excessive lighting is too often used beyond what is needed for driving, or shopping, or Friday-night football. The electric light bulb is touted as one of the most significant technological advancements of human beings. It ranks right up there with the wheel, control of fire, antibiotics, and dynamite. But as with any new and spectacular technology, there are invariably unintended consequences. With electric light has come an obliteration of night in much of the modern world; both outside in the city, and indoors during what was once "night," according to the natural position of the sun. Life has evolved for several billion years with a reliable cycle of bright light from the sun during the day, and darkness at night. This has led to the development of an innate circadian rhythm in our physiology; that circadian rhythm depends on the solar cycle of night and day to maintain its precision. During the night, beginning at about sunset, body temperature drops, metabolism slows, hunger abates, sleepiness increases, and the hormone melatonin rises dramatically in the blood. This natural physiological transition to night is of ancient origin, and melatonin is crucial for the transition to proceed as it should. We now know that bright, short-wavelength light — blue light — is the most efficient for suppressing melatonin and delaying transition to night-time physiology; meanwhile, dimmer, longer-wavelength light — yellow, orange, and red, from a campfire or a candle, for example — has very little effect. Bright light from the sun contains blue light, which is a benefit in the morning when we need to be alert and awake; but whether we are outdoors or indoors, when bright, blue light comes after sunset, it fools the body into thinking it's daytime.
8-19-18 Why kids are obsessed with the Fortnite video game
Kids' video game obsession isn't really about video games. It's about unmet psychological needs. Many parents are concerned with their child's seemingly obsessive video game play. Fortnite, the most recent gaming phenomenon, has taken the world by storm and has parents asking whether the shooter game is okay for kids. The short answer is yes, Fortnite is generally fine. Furthermore, parents can breathe easier knowing that research suggests gaming (on its own) does not cause disorders like addiction. However, there's more to the story. A comprehensive answer to the question of whether video games are harmful must take into account other factors. Fortnite is just the latest example of a pastime some kids spend more time on than is good for them. But parents need to understand why kids play as well as when to worry and when to relax. The word "addiction" gets tossed around quite a bit these days. It's not uncommon to hear people say that they are addicted to chocolate or shoe shopping, but if it isn't causing serious harm and impairment to daily function, it isn't an addiction. It's an overindulgence. This isn't just semantics. An addiction involves a lack of control despite adverse consequences. Parents may worry their kids are addicted, but if the child can pull themselves away from a game to join the family for a conversation over dinner, and shows interest in other activities, like sports or socializing with friends, then they are not addicted. Generally, parents panic when their kid's video game playing comes at the expense of doing other things like studying or helping around the house. But let's be honest, kids have been avoiding these activities for ages. Equally true is the fact parents have been complaining about their unhelpful children well before the first video game was plugged into its socket.
8-18-18 Ancient Egypt: Cheese discovered in 3,200-year-old tomb
A substance found by archaeologists working in an Ancient Egyptian tomb has proved to be one of the oldest cheeses ever discovered. Several years ago, the team discovered broken jars in the tomb of Ptahmes, a high-ranking Egyptian official. The archaeologists found a "solidified whitish mass" in one of the jars which they suspected was food but were unsure which kind. Now a study has identified it as cheese, dating from 3,200 years ago. The discovery is significant as there has been no previous evidence of Ancient Egyptian cheese production, authors of the report, published in the journal Analytical Chemistry, said. "The material analysed is probably the most ancient archaeological solid residue of cheese ever found to date," said Dr Enrico Greco, from the University of Catania, who worked with colleagues at the Cairo University in Egypt to determine its identity. "We know it was made mostly from sheep's and goat's milk, but for me it's really hard to imagine a specific flavour." The ancient cheese would have had a "really, really acidy" bite, cheese historian and chemistry professor Paul Kindstedt told the New York Times. The researchers say they also found traces of a bacterium that can cause an infectious disease known as brucellosis, which comes from consuming unpasteurised dairy products. Symptoms include fever, sweating and muscle aches, and the disease still exists today. If confirmed, it would be the oldest evidence of such a case. The tomb where the cheese was found belonged to Ptahmes, an Egyptian official who was mayor of the ancient city of Memphis. The burial site, at the Saqqara necropolis near Cairo, was first unearthed in 1885. But, after being lost to shifting sands, it was rediscovered in 2010.
8-17-18 The galaxy is full of ‘water world’ exoplanets where life could evolve
Analysis of data from 4000 exoplanets reveals that around a third are rich in water – and many have more water than Earth. Planets with atmospheres of steam, oceans of liquid water and cores of rock surrounded by solid ice may be abundant around distant stars. An analysis of the 4000 or so known exoplanets estimates that around 1400 are water-rich worlds, potentially raising the stakes that some may harbour life. Although a few individual water world exoplanets have been identified, the new data suggests they may be abundant. “Life could develop in certain near-surface layers on these water worlds, if the pressures, temperatures and chemical conditions are appropriate,” says Li Zeng of Harvard University in Cambridge, Massachusetts, who presented his results today in Boston at the Goldschmidt geochemistry conference. On many of them, water accounts for more than half the weight of the planet, compared with just 0.02 per cent on Earth, he says. Zeng and his colleagues worked out the likely compositions of exoplanets by analysing measurements of the radius and mass of each, and modelling how they might have evolved from their host stars. They relied on a well-established theory of how planets evolve from the gases and material that form discs around newly formed stars. Small rocky planets like Mercury, Venus, Earth and Mars form in the hot, “terrestrial” zone closest to the star. Further out from the star, everything changes beyond a “frost-line”, where temperatures are low enough for water vapour to condense into ice grains and clump together into icy planets. Some then become enshrouded by huge quantities of gases, mostly hydrogen, and end up as giant planets like Jupiter, Saturn, Uranus and Neptune.
8-17-18 Cheese found in an Egyptian tomb is at least 3,200 years old
The white lump contained signs of a bacteria that causes the infectious disease brucellosis. What may be the oldest known solid cheese has been found in an ancient Egyptian tomb. Made from a mixture of cow milk and either sheep or goat milk, the cheese filled a broken clay jar unearthed from a 13th century B.C. tomb for Ptahmes, the mayor of the ancient city of Memphis, researchers report online July 25 in Analytical Chemistry. Chemist Enrico Greco, who did the work while at the University of Catania in Italy, and colleagues used mass spectrometry to analyze the antique cheese — now a white, soapy lump weighing “several hundred grams.” Besides milk and whey proteins, the cheese contained remnants of bacteria that cause an infection called brucellosis, adding to evidence that ancient Egyptians may have grappled with the disease, Greco says. Cheese making predates the new find by thousands of years, but preserved cheese is hard to come by (SN: 1/26/13, p. 16). Archaeologists found older curds draped around the necks of Bronze Age mummies in China, a different group of researchers reported in 2014 in the Journal of Archaeological Science. “There are other samples of dairy products in the literature, but not solid cheeses in the strict sense,” Greco says.
8-16-18 Eating a low-carb diet may shorten your life – unless you go vegan too
People following low-carb diets have been found to have a higher risk of mortality, except when people shun animal fats and protein too. Low carbohydrate diets have been linked to reduced longevity – except for when dieters ditch the steak for plant-based alternatives. An analysis of data from 15,400 people in the US has found a U-shaped relationship between mortality and carbohydrate intake. The study found that the people who lived longest tended to be those who got around 50 to 55 per cent of their energy intake from carbohydrates. At the age of 50, such people could expect to live a further 33 years. This is one year longer than people who get 70 per cent or more of their energy from carbs, and four years longer than people get less than 30 per cent of their calories from carbohydrates. Sara Seidelmann, at Brigham and Women’s Hospital in Boston, and her colleagues wondered if the types of fat and protein people eat on low-carb diets might contribute to reduced longevity. Diving into the data, they found that when people replaced carbs with meat such as lamb, pork, beef and chicken – typical for low carb dieters in Europe and the US — their mortality increased. But the opposite was true for those who instead ate plant-based sources of protein and fat such as legumes, vegetables and nuts. “The more you exchange plant-based fats and proteins for carbohydrates, the more the risk lowers,” says Seidelmann.
8-16-18 Exposure to insecticide DDT linked to having a child with autism
Although DDT has been banned for decades in many countries, exposure to its breakdown products may be influencing whether mothers have autistic babies. Although banned for decades in most rich countries, the insecticide DDT may be influencing whether babies born today and in the future develop autism. A study in Finland has found that mothers that show signs of high DDT exposure in their blood may be more likely to have children with autism. DDT was sprayed in large amounts from the 1940s onwards, to kill disease-carrying mosquitoes. But it was widely banned in Western nations in the 1970s and 1980s, after evidence mounted that it caused cancers in laboratory animals and impaired reproduction in wildlife. But the insecticide takes decades to break down, so people are still absorbing it from contaminated water and food. Once consumed, it lodges in the body’s fat, and circulates in the blood – and is known to pass to fetuses during pregnancy. To see if this might be linked to autism, Alan Brown of Columbia University in New York and his colleagues analysed blood samples taken in Finland between 1983 and 2005 from more than a million women during the early stages of pregnancy. Like in the UK and US, DDT was used widely in Finland before it was banned. The team screened these blood samples for DDE – a long-lived breakdown product of DDT – and found that, on average, DDE levels were higher in mothers who went on to have autistic children. The mothers of children without autism had, on average, 811 picograms of DDE present in each millilitre of their blood, but the average was 1032 picograms in the mothers of autistic children.
8-16-18 A drug’s weird side effect lets people control their dreams
Researchers have developed the most effective technique for lucid dreaming yet, and it may allow people to fulfil fantasies and overcome nightmares and phobias. Have you ever wanted to fly? A drug that helps people control their dreams could let you try it from the comfort of your own bed. A small number of people naturally have lucid dreams, meaning they can recognise when they’re dreaming and steer the storyline they experience. Some others can learn to induce them using cognitive techniques. The practice is most commonly used to pursue fantasies like flying, but it may also help to overcome fears and nightmares, says Benjamin Baird at the University of Wisconsin-Madison. However, its therapeutic potential has been limited by the fact that it’s often hard to achieve. Now, Baird and his colleagues have developed the most effective method yet for promoting lucid dreams, by combining cognitive training with a drug called galantamine that is typically used to slow Alzheimer’s disease. The researchers taught 121 adults aged 19 to 75 a cognitive technique for stimulating lucid dreams called mnemonic induction of lucid dreams. It involves picking a feature of a previous dream called a “dreamsign” that can serve as a reminder to become lucid when encountered again. After learning this technique, the volunteers were given capsules of galantamine, a treatment for mild to moderate Alzheimer’s disease. This drug boosts the brain chemical acetylcholine, which boosts memory, but also promotes rapid eye movement (REM) sleep, the phase in which dreams are most common. “Just as it might remind you to pick up milk on your way home, it might remind you to become lucid when you see your dreamsign,” says Baird.
8-16-18 Ancient Egyptian mummification 'recipe' revealed
Examination of a mummy has revealed the original ancient Egyptian embalming recipe - first used to preserve bodies. A battery of forensic chemical tests carried out on a mummy that dated from 3,700-3,500 BC revealed the recipe and confirmed that it was developed far earlier and used more widely than previously thought. The Egyptian Museum in Turin, Italy, is now home to the mummy in question. The findings are published in the Journal of Archaeological Science. Dr Stephen Buckley, an archaeologist from the University of York, told BBC News that this mummy "literally embodies the embalming that was at the heart of Egyptian mummification for 4,000 years". Dr Buckley and his colleagues worked out the chemical "fingerprint" of every ingredient, although each element could have come from a number of sources. When mixed into the oil, that resin would have given it antibacterial properties, protecting the body from decay. "Until now," he said, "we've not had a prehistoric mummy that has actually demonstrated - so perfectly through the chemistry - the origins of what would become the iconic mummification that we know all about."
8-15-18 Banana-y bread and onion beer: How yeast can trick our tastebuds
Maker of beer, bread and wine, yeast is our biggest microbial friend. Now we're engineering weird new flavours with it - even lager that tastes of something. FLORIAN BAUER’S recipe doesn’t sound very wine-like. Take water, sugar, some amino acids and yeast, and let it ferment. And yet… “When you smell it you say, ‘yes, that’s wine!’,” says Bauer, a wine scientist at Stellenbosch University in South Africa. Most people would casually assume that a wine’s nose is all about the grapes, just as a beer’s flavour is all in the hops and barley. Not so. Much of the taste of these beverages comes from an organism too small to see with the naked eye. From a sugar-loving fungus, to be precise, one we use to produce not just wine, beer and sake, but also bread, some of our most toothsome cheeses and more. Unwittingly at first, we have been domesticating and breeding this single-celled organism for millennia. The resulting legion of faithful servants can claim, arguably more than any dog, to be humanity’s best friend. We’re talking about yeast – or more precisely Saccharomyces cerevisiae, or brewer’s or baker’s yeast. But while yeast’s fermentative properties are well known, we are only now getting to grips with just how much it contributes to flavour. As researchers prise open its secrets, they are finding new and sometimes truly weird ways to tickle tipplers’ and gourmands’ taste buds. Beer like banana milkshake? Bread with a truly nutty crunch? With yeast, everything is possible. “In terms of flavour, you can go as far as your mind can take you,” says Jan Steensels, a molecular biologist at the Flemish Institute for Biotechnology (VIB) in Belgium.
8-15-18 How the humble cabbage can stop cancers
Scientists say they have discovered why some vegetables - including cabbage, broccoli and kale - can reduce the risk of bowel cancers. That cruciferous veg is good for the gut has never been in doubt but a detailed explanation has been elusive. The team at the Francis Crick Institute found anti-cancer chemicals were produced as the vegetables were digested. Cancer Research UK said there were plenty of reasons to eat more veg. The work focused on how vegetables alter the lining of the intestines, by studying mice and miniature bowels growing in the lab. Like the skin, the surface of the bowels is constantly being regenerated in a process that takes four to five days. But this constant renewal needs to be tightly controlled, otherwise it could lead to cancer or gut inflammation. And the work, published in the journal Immunity, showed chemicals in cruciferous vegetables were vital.
8-15-18 Cancer drugs may help the liver recover from common painkiller overdoses
In mice given a toxic dose of acetaminophen, an anticancer medication kept liver cells alive. Experimental anticancer drugs may help protect against liver damage caused by acetaminophen overdoses. In mice poisoned with the common painkiller, the drugs prevented liver cells from entering a sort of pre-death state known as senescence. The drugs also widened the treatment window: Mice need to get the drug doctors currently use to counteract an overdose within four hours or they will die, but the experimental drugs worked even 12 hours later, researchers report August 15 in Science Translational Medicine. If the liver-rescuing results are verified in clinical trials, this therapy may buy time for people who accidentally or intentionally overdose on Tylenol or other medications containing the painkiller acetaminophen. In the United States, such overdoses occur more than 100,000 times a year and are the leading cause of acute liver failure. Many people get treatment on time or recover on their own, but some require emergency liver transplants. And 150 people on average die of acetaminophen poisoning each year. Currently, doctors treat such overdoses with N-acetylcysteine, an antidote that must be given within eight hours of ingesting a potentially fatal dose. Some people don’t make it to a doctor in time, and will die or need transplants. In the study, untreated mice died within 18 hours. But mice given the new drugs survived at least a week until researchers sacrificed the rodents to examine their livers.
8-15-18 Children may be especially vulnerable to peer pressure from robots
Adults appear able to resist the machines’ influence. Peer pressure can be tough for kids to resist, even if it comes from robots. School-aged children tend to echo the incorrect but unanimous responses of a group of robots to a simple visual task, a new study finds. In contrast, adults who often go along with the errant judgments of human peers resist such social pressure applied by robots, researchers report August 15 in Science Robotics. “Rather than seeing a robot as a machine, children may see it as a social character,” says psychologist Anna-Lisa Vollmer of Bielefeld University, Germany. “This might explain why they succumb to peer pressure [applied] by robots.” Little is known about how either adults or children respond to the behavior of lifelike robots designed to interact with people, for example, as museum tour guides, child-care assistants and teaching aids. In a preliminary examination of the influence of social robots, Vollmer’s group adapted a 1950s social psychology experiment in which most adults agreed with groups of peers who had been coached to say that lines of different lengths were in fact the same length (SN Online: 5/15/18).
8-15-18 Replacing your boss with a cruel robot could make you concentrate more
A mean robot watching over you increases your focus on the most important parts of a task more than a friendly robot or even no robot at all. Cruel robot overlords get more out of their human subjects than nice ones. The mere presence of an unkind robot seems to improve our cognitive abilities, more than being watched by a friendly robot or even no robot at all. The effect of a robot observer on human performance was tested using the Stroop task, a test in which words printed in different colours appear on a screen, and test subjects must identify the colour, ignoring the word itself. We’re usually worse at this – either taking longer to answer or making mistakes – when the colour and the word clash, like when the word “blue” is printed in green letters. To see how a robot would affect the test, Nicolas Spatola at the University of Clermont Auvergne in France and his colleagues added a small humanoid robot perceived either as friendly or mean into the experiment. First, participants sat and had a conversation with the robot, which was programmed to answer questions either positively – “I think we could become friends”, or negatively – “I do not value friendship”. Then, they worked on a series of Stroop tasks on a screen, while the robot sat and watched them. The subjects paired with mean robots were faster and made fewer mistakes than those paired with friendly ones or with no robot at all. “Participants will give more attention to the ‘bad’ robot because maybe it could be dangerous, maybe it could do something that you have not predicted, maybe it could be mean towards you or it judges you,” says Spatola.
8-15-18 Why taking ayahuasca is like having a near-death experience
A psychedelic drug produces effects similar to near-death experiences. The finding suggests changes to brain activity may explain such paranormal phenomena. A psychedelic drug taken as part of the South American plant brew ayahuasca produces effects that are strikingly similar to near-death experiences, a study has found. That means that feelings of leaving the body or inner peace associated with life-threatening experiences may simply be explained by changes in how the brain works, and aren’t evidence of paranormal phenomena, say the researchers. DMT is the main psychoactive ingredient in ayahuasca, which is used as a sacrament by some indigenous peoples in the Amazon. People who take it commonly describe feeling that they transcend their body and enter another realm. Chris Timmerman and colleagues at Imperial College London gave DMT intravenously to 13 volunteers and asked them to fill in a questionnaire used to assess near-death experiences. In an earlier session, the same volunteers were given an intravenous placebo, and they did not know which session would involve the real drug. After the DMT session, all 13 participants got results on the questionnaire that met the criteria for a near-death experience. In particular, they reported feeling as though they entered an “unearthly environment”, feeling “incredible peace or pleasantness”, having heightened senses and a feeling of unity with the universe. When their responses were compared with responses from a set of 13 people who had reported actual near-death experiences, there were no statistically significant differences between the groups.
8-15-18 Sterile fish could help wild salmon dodge the ‘gene pollution’ effect
Farmed Atlantic salmon make the local wild salmon population weaker. Making them sterile could work – but there’s a catch. FROM Norway to Canada, farmed Atlantic salmon are escaping in such large numbers that they are a threat to the local salmon. This could be prevented by making the farmed fish sterile. But there is a catch: the sterile fish are less nutritious. Salmon farming has satisfied soaring demand without the need to catch ever more wild salmon. But it has also created an entirely new threat. Farmed salmon have been transformed into a domesticated animal by selective breeding. They eat more, grow faster and have less fear of predators. This means they are less likely to survive in the wild and so weaken wild salmon when they interbreed with them. Norway is tackling the problem in several ways, from trying to reduce the number of escapees to having snorkellers spear farmed salmon that turn up in rivers before they can interbreed. But some experimental farms there are already testing the ultimate solution: making farmed salmon sterile. One way to do this is to briefly pressurise fertilised eggs, which makes them retain an extra set of chromosomes. The resulting fish are triploid: they have three sets of chromosomes. This method is already used worldwide to sterilise trout for release in rivers. Now David Murray at the University of East Anglia, UK, has confirmed that triploid salmon are also effectively sterile. The females didn’t develop gonads and while the males did produce sperm, less than 1 per cent of the eggs they fertilised survived to the 5-week stage, when the experiment stopped (Royal Society Open Science, DOI: 10.1098/rsos.180493).
8-14-18 New Scientist Live: the sophisticated home life of Neanderthals
We once thought Neanderthals were less advanced than humans, but Matt Pope will argue at New Scientist Live that Neanderthal families lived rich domestic lives. We once thought of Neanderthals as crude and unintelligent – not any more. Archaeological evidence suggests they were capable of symbolic thought, had some capacity for speech, and probably carried out elaborate burial rituals. They may even have taught modern humans new skills when the two species met and interbred. Now we are starting to discover what Neanderthal home life was like, and the caricature of prehistoric cave men couldn’t be more wrong, Matt Pope of University College London will argue at New Scientist Live next month. It turns out that prehistoric humans started living in “homes” far earlier than we had thought. This unseen revolution included Neanderthals who, like Homo sapiens, had complex tools and mastery of fire. Neanderthals lived in family groups consisting of five to 10 individuals, and cared for their sick and injured with a medical cabinet that included painkillers and penicillin. Contrary to expectations, some Neanderthals were even vegetarian. Others seasoned their food with wild herbs. And they were making porridge 32,000 years ago, long before farming was invented. Hear more about the domestic life of Neanderthals when Pope speaks at New Scientist Live in London on Sunday 23 September.
8-14-18 A resurrected gene may protect elephants from cancer
LIF6 instructs damaged cells to self-destruct before the disease has a chance to take hold. Elephants rarely succumb to cancer. That’s surprising given how large the animals grow and how long they can live, which should provide more opportunities for cells to morph into cancer cells. A newly described gene that was brought back from the dead may take part in protecting the animals from the disease. A deep dive into elephants’ evolutionary history revealed a defunct gene called LIF6 that was somehow resurrected roughly 59 million years ago, around the time that elephants’ ancestors began to develop larger body sizes. Found only in elephants and their ancestral kin, LIF6 is triggered by another gene, TP53, to put cells out of commission at the first sign of damage before they turn cancerous, researchers report online August 14 in Cell Reports. Previous research on elephants’ cancer-fighting powers focused on TP53, which most animals have. It was known that the gene makes a protein that detects cellular DNA damage and signals for a cell to repair itself or self-destruct, which also helps stop damaged cells from turning into cancer cells. In 2015, researchers found that elephants have 20 TP53 copies, compared with just one for humans and other mammals (SN: 11/14/15, p. 5).
8-14-18 Sticking brain cells together with glue could boost and protect memory
Can a chemical that reinforces the connections in our brains prevent the destruction of memories in ageing and Alzheimer’s? It seems to work in mice. Can we bolt brain cells together to protect our memories from ageing or Alzheimer’s? It’s an eccentric idea, but there are signs it could work. Rahul Kaushik of the German Center for Neurodegenerative Diseases in Magdeburg and his colleagues have created a molecule to reinforce the connections between brain cells called neurons, acting like the steel bars in reinforced concrete. Although the approach hasn’t yet been tested in people, injecting this molecule into the brains of mice seems to improve their memories. “It is very clever and has a natural logic to it,” says John Aggleton of Cardiff University, UK. The connections between brain cells, known as synapses, allow signals to jump from one cell to another. Our memories are made of networks of strengthened synapses between millions of brain cells distributed through our heads. To reinforce this, Kaushik’s team has designed a molecule called CPTX. This chemical binds to compounds on the surface of brain cells on either side of a synapse, creating an artificial bridge between the two cells. In Alzheimer’s disease, people gradually lose synapses for decades before the damage is enough to start causing memory loss and confusion. “The idea is you don’t allow the synapses to go away,” says Kaushik. “We don’t let two neurons detach from each other completely.”
8-14-18 There is no evidence that the weedkiller glyphosate causes cancer
Agrichemical firm Monsanto has been ordered to pay $289 million to a man who says its products caused his cancer – but scientific evidence for links to cancer is lacking . Does weedkiller cause cancer? According to a ruling by a Californian court last week, yes. Monsanto, the agricultural chemicals company, has been ordered to pay $289 million to Dewayne Johnson, a groundskeeper who says his terminal cancer was caused by their products Roundup and RangerPro, which contain the chemical glyphosate. The ruling has led to Greenpeace calling for sales of the weedkiller to be restricted and shares in Monsanto’s parent company Bayer to drop. Meanwhile, Thérèse Coffey, an environment minister in the UK government, is under fire for her tacit support, having tweeted that she was about to “deploy the amazing Roundup!”. But while the jury ruled that Johnson’s cancer, a non-Hodgkin’s lymphoma, was probably caused by glyphosate, the evidence for a link is extremely thin. “I don’t think there’s any good scientific evidence,” says Paul Pharoah, who studies cancer epidemiology at the University of Cambridge. We simply don’t know if glyphosate was a relevant cause of cancer in this case or any another, he says. In 2015, the International Agency for Research on Cancer (IARC), a branch of the World Health Organization, said that glyphosate is “probably carcinogenic”, having reviewed the evidence.
8-14-18 Being human: Big toe clung on longest to primate origins
Scientists have found that our big toe was one of the last parts of the foot to evolve, a study suggests. As our early ancestors began to walk on two legs, they would also have hung about in trees, using their feet to grasp branches. They walked differently on the ground, but were still able to move around quite efficiently. The rigid big toe that eventually evolved gives efficient push-off power during walking and running. The findings have been published in the journal Proceedings of the National Academy of Sciences. In this new study, scientists made 3D scans of the toe bone joints from living and fossil human relatives, including primates such as apes and monkeys, and then compared them to modern day humans. They overlaid this information onto an evolutionary tree, revealing the timing and sequence of events that produced the human forefoot. The main finding is that the current shape of the bones in the big toe, or "hallux" in anatomical language, must have evolved quite late in comparison with the rest of the bones that they investigated. In an interview with the BBC, lead author of the study Dr Peter Fernandez, from Marquette University in Milwaukee, said: "Our ability to efficiently walk and run on two feet, or be 'bipedal', is a crucial feature that enabled humans to become what they are today. For everything to work together, the foot bones first had to evolve to accommodate the unique biomechanical demands of bipedalism". He then said: "The big toe is mechanically very important for walking. In our study, we showed that it did not reach its modern form until considerably later than the other toes."
8-13-18 We’ve identified the brain cells that let you control urination
We’ve all been there – desperately holding on for a toilet. Now the brain cells that help us do it have been identified, which may lead to new incontinence treatments. We’ve all been there – desperately holding on until reaching a toilet. Now researchers have discovered the brain cells that help mammals do this – a finding that may lead to new treatments for incontinence. Just like humans, mice learn to control when and where they urinate. To attract mates, males intentionally leave dabs of urine wherever they pick up the scent of females. Lisa Stowers of the Scripps Research Institute in La Jolla, California, and her colleagues used this behaviour to identify the brain cells involved in this voluntary urination. The team had previously identified neurons in the brainstem region – the part of the brain that extends downward into the spinal cord – that control bladder muscles. But these alone are not enough for a mouse to urinate – muscles that constrict the urethra, the tube that empties the bladder, need to relax too. Analysing slices of cells from this region of the brain, they identified around 200 neurons that didn’t behave the same way as the other bladder-relaxing cells. When the team artificially stimulated these neurons, the mice urinated on demand. Measurements made using implanted pressure recorders showed that activation of these neurons relaxes the muscles that normally hold the urethra closed. Chemically blocking these neurons stopped mice from urinating when they were exposed to female scents.
8-13-18 Tiny bits of RNA can trigger pain and itchiness
Two microRNAs may shed light on the causes of chronic nerve pain and itch. A microRNA called miR-30c-5p contributes to nerve pain in rats and people, a new study finds. A different microRNA, miR-711, interacts with a well-known itch-inducing protein to cause itching, a second study concludes. Together, the research highlights the important role that the small pieces of genetic material can play in nerve cell function, and may help researchers understand the causes of chronic nerve pain and itch. MicroRNAs help regulate gene activity and protein production. The small molecules play a big role in controlling cancer (SN: 8/28/10, p. 18) and other aspects of health and disease (SN: 2/20/16, p. 18). Usually, microRNAs work by pairing up with bigger pieces of RNA called messenger RNAs, or mRNA. Messenger RNAs contain copies of genetic instructions that are read by cellular machinery to build proteins. When microRNAs glom onto the messengers, the mRNA can be degraded or the microRNAs can prevent the protein-building machinery from reading the instructions. Either way, the result is typically to dial down production of certain proteins. In the case of nerve pain, miR-30c-5p limits production of an important protein called TGF-beta that’s involved in controlling pain, María Hurlé, a pharmacologist at the University of Cantabria in Santander, Spain, and colleagues report August 8 in Science Translational Medicine. The researchers discovered the link in experiments with mice, rats and people.
8-13-18 Strange brains offer a glimpse into the mind
‘Unthinkable’ and ‘The Disordered Mind’ tell stories about people and neuroscience. To understand the human brain, take note of the rare, the strange and the downright spooky. That’s the premise of two new books, Unthinkable by science writer Helen Thomson and The Disordered Mind by neuroscientist Eric R. Kandel. Both books describe people with minds that don’t work the same way as everyone else’s. These are people who are convinced that they are dead, for instance; people whose mental illnesses lead to incredible art; people whose memories have been stolen by dementia; people who don’t forget anything. By scrutinizing these cases, the stories offer extreme examples of how the brain creates our realities. In the tradition of the late neurologist Oliver Sacks (SN: 10/14/17, p. 28), Thomson explores the experiences of nine people with unusual minds. She travels around the world to interview her subjects with compassion and curiosity. In England, she meets a man who, following a bathtub electrocution, became convinced that he was dead. (Every so often, he still feels “a little bit dead,” he tells Thomson.) In Los Angeles, she spends time with a 64-year-old man who can remember almost every day of his life in extreme detail. And in a frightening encounter in a hospital in the United Arab Emirates, she interviews a man with schizophrenia who transmogrifies into a growling tiger. By visiting them in their element, Thomson presents these people not as parlor tricks, but as fully rendered human beings.
8-13-18 Winged reptiles thrived before dinosaurs
Palaeontologists have found a new species of pterosaur - the family of prehistoric flying reptiles that includes pterodactyl. It is about 210 millions years old, pre-dating its known relatives by 65 million years. Named Caelestiventus hanseni, the species' delicate bones were preserved in the remains of a desert oasis. The discovery suggests that these animals thrived around the world before the dinosaurs evolved. Pterosaurs are the oldest flying vertebrates; the first to crack the evolutionary puzzle of powered flight. As a result of this engineering, their delicate, bird-like skeletons are often found in quite a crushed state. "Most of them are heavily distorted; literally like roadkill," says lead author Prof Brooks Britt, from Brigham Young University in Utah. Finding the perfectly preserved skull of this early species provided researchers with a rare opportunity to study its structure. "The bones are so delicate, you can't take them all the way out of the rock because they would just fall apart," explains Prof Britt. Instead, the team used a CT scanner to build a digital profile of the skull, and then printed a detailed 3D model. This revealed a remarkably complex set of teeth, including sharp fangs protruding from the front of the mouth, and blade-like teeth along the lower jaw.
8-13-18 Asteroid strike may have forged the oldest rocks ever found on Earth
The oldest rocks ever found are over four billion years old and we don’t know how they formed – but a massive asteroid bombardment may be responsible. The oldest rocks ever found on Earth may have been born in an asteroid bombardment that happened over four billion years ago. Found at the Acasta River in Canada about three decades ago, these ancient granite, or felsic, rocks formed approximately 600 million years after the creation of the Earth, before any life arose. They contain a distinctive mix of elements compared to rocks that formed later, suggesting they may have been created by a different geological process. Tim Johnson at Curtin University, Australia and his colleagues simulated the potential conditions in which these rocks could have formed. They concluded that partial melting of the Earth’s surface at a temperature of 800 to 900°C under very low pressure may have contributed to their creation. It would have been impossible for the young Earth reach such high temperatures unaided, Johnson says. Instead, he says the late heavy bombardment, a period of intense asteroids impacts on Earth that also widely cratered the moon, may be responsible. “We know that the Earth was bombarded for 600–700 million years after its birth,” Johnson says. “The fact that they are the only felsic rocks older than four billion years that we know of instantly got me thinking about impacts as a possible cause.”
8-13-18 Tools reveal Easter Island may not have had a societal collapse
Tools used to make Easter Island’s famous statues have yielded a clue that suggests the Rapa Nui inhabitants that made them all got along with each other. The indigenous people of Easter Island, the Rapa Nui, were thought to have undergone a societal collapse some time after the 17th century due to in-fighting over depleted natural resources. But a new study of the tools they used to carve their famous moai statues adds to the evidence that the Rapa Nui in fact had a highly collaborative society. Easter Island covers just 170 square kilometres and is one of the most remote places on Earth, sitting thousands of miles from the nearest landmass in the south-eastern Pacific Ocean. Once lush with palms, the island was devoid of trees by about 1500. Some scientists have suggested that the resulting erosion led to food shortages, and the lack of wood limited boat building, which could have led to violence and the eventual collapse of Rapa Nui society. Dale Simpson at the University of Queensland says the evidence suggests otherwise. He and his colleagues used maps of stone quarries compiled by the Easter Island Statue Project to trace the path of the volcanic basalt mined and formed into chisels, picks, and axe-like tools. These were used for making canoes as well as the moai, massive monoliths carved into human figures that are set along the coastline.
8-11-18 Weedkiller glyphosate 'doesn't cause cancer' - Bayer
Pharmaceutical group Bayer has dismissed claims that an ingredient used in weed killers is carcinogenic. The German company, which owns agriculture giant Monsanto, says herbicides containing glyphosate are safe. On Friday, Monsanto was ordered to pay $289m (£226m) damages to a man who claimed the products caused his cancer. A Californian jury said Monsanto should have warned users about the dangers of its Roundup and RangerPro weedkillers. Bayer completed its $66bn takeover of Monsanto in June. A Bayer spokesperson told the BBC the two companies operate independently. In a statement the company said: "Bayer is confident, based on the strength of the science, the conclusions of regulators around the world and decades of experience, that glyphosate is safe for use and does not cause cancer when used according to the label." The landmark lawsuit was the first to go to trial alleging a glyphosate link to cancer. The claimant, groundsman Dewayne Johnson, was diagnosed with non-Hodgkin's lymphoma in 2014. His lawyers said he regularly used a form of RangerPro while working at a school in Benicia, California. He is among more than 5,000 similar plaintiffs across the US. Glyphosate is the world's most common weedkiller. The California ruling could lead to hundreds of other claims against Monsanto. The company said it intends to appeal against the verdict. Glyphosate was introduced by Monsanto in 1974, but its patent expired in 2000, and now the chemical is sold by various manufacturers. In the US, more than 750 products contain it. In 2015, the International Agency for Research on Cancer, the World Health Organisation's cancer agency, concluded that glyphosate was "probably carcinogenic to humans".
8-10-18 Coral reefs 'weathered dinosaur extinction'
Corals may have teamed up with the microscopic algae which live inside them as much as 160 million years ago, according to new research. The two organisms have a symbiotic relationship, meaning they need each other to survive. But this partnership was previously thought to have developed about 60 million years ago. The new findings suggest that reef algae may have weathered significant environmental changes over time. This includes the mass extinction that wiped out most of the dinosaurs. Algae's resilience to temperature changes has been of concern to scientists recently, as warming events on the Great Barrier Reef have seen the coral "bleached" of its algae. The study, conducted by an international team of scientists, aimed to explore the diversity of algae species co-habiting with corals. Looking at the species group Symbiodinium, the researchers found that it contained more varieties than previously thought. Although scientists had been aware of the algae's diversity, it had not been classified into many separate species - which now appears to be the case. Using DNA analysis, the team found that these algae likely evolved and began their partnership with coral during the Middle Jurassic, well before the extinction event that affected the dinosaurs. "Our recognition of the true origin of those microbes that give corals life is major revelation," lead author Prof Todd LaJeunesse told BBC News. "They are way older than was previously estimated. Meaning that [this partnership has] been around for a hell of a long time!" added the Pennsylvania State University researcher.
8-10-18 The first gene-silencing drug wins FDA approval
Using RNA interference, patisiran prevents symptoms by blocking DNA instructions. A Nobel Prize–winning discovery — that small double-stranded RNA molecules can silence genes by interrupting the translation of DNA’s instructions into proteins — is finally delivering on its medical promise. The first drug that takes advantage of this natural biological process, called RNA interference, was approved August 10 by the U.S. Food and Drug Administration. It targets a rare hereditary disease that causes misshapen proteins to build up in patients’ nerves, tissues and organs, causing loss of sensation, organ failure and even death. Heredity transthyretin amyloidosis, or ATTR, affects about 50,000 people worldwide. This drug will help the subset of those patients who have neurological impairments. Called patisiran, the drug uses specially designed pieces of RNA to silence a mutated gene that, when active in the liver, is responsible for patients’ symptoms. In a recent 18-month clinical trial, patients who received patisiran injections every three weeks showed a slight decrease in neurological symptoms, whereas patients on the placebo worsened overall. It’s not a cure — people still have the genetic mutation — but the treatment prevents the disease from progressing. This approval is “just the beginning,” says Craig Mello of the University of Massachusetts Medical School in Worcester, who co-discovered the process of RNA interference in roundworms (SN: 10/7/06, p. 229). Many more drugs using the same approach, for diseases ranging from hemophilia to HIV, are winding through clinical trials.
8-10-18 Dehydration hurts concentration
When you find yourself struggling to concentrate on something, try having a glass of water. That’s the conclusion of a new, detailed analysis of more than 30 studies into the effects of dehydration, NPR.org reports. The researchers, from the Georgia Institute of Technology, found that going thirsty had no significant impact on reaction times and other basic cognitive functions. But for more complex tasks that require focused attention or coordination, dehydration did appear to impair people’s performance. Examples include “maintaining focus in a long meeting, driving a car, [or] a monotonous job in a hot factory,” said study leader Mindy Millard-Stafford. “Higher-order functions like doing math or applying logic also dropped off.” Millard-Stafford and her colleagues found that cognitive impairment tended to begin when people lost 2 percent of the water in their body. For the average person, that equates to about 35 fluid ounces of sweat—roughly what you’d produce with an hour of moderate hiking.
8-10-18 How to be happier
The most popular course at Yale University teaches students how to be happy, said Adam Sternbergh. He took it—and made you a cheat sheet. Professor Laurie Santos didn’t set out to create the most popular course in the history of Yale University and the most talked-about college course in America. She just wanted her students to be happy. And they certainly look happy as they file into a church—a literal church, Battell Chapel, that’s been converted to a lecture hall—on the Yale campus on a sunny April afternoon, lugging backpacks and chatting before taking their seats in the pews. They’ve just returned from a two-week spring break. The weather outside is gorgeous. Professor Santos is playing her preclass get-pumped playlist featuring the Black Eyed Peas’ “I Gotta Feeling.” And, let’s not forget, all of these students are currently going to Yale. What’s not to be happy about? Quite a bit, it turns out. The very fact that Santos’ new course, Psych 157: Psychology and the Good Life, is so wildly popular, with over 1,200 enrolled students, suggests that she’s on to something when she tells me one day, prelecture, “College students are much more overwhelmed, much more stressed, much more anxious, and much more depressed than they’ve ever been. I think we really have a crisis writ large at colleges in how students are doing in terms of self-care and mental health.” Then she adds, “Sadly, I don’t think it’s just in colleges.” Santos is right. College students aren’t happy. According to a recent survey by the American College Health Association, 52 percent of students reported feeling hopeless, while 39 percent suffered from such severe depression that they had found it difficult to function at some point during the previous year.
8-9-18 We have measured the speed of death and it’s 2 millimetres an hour
Biologists have watched death spread across a living cell for the first time, and discovered that it travels in a steady wave in the same way that wildfires do. We have been able to watch death travelling for the first time – and it moves in a wave at a pace of 30 micrometres per minute. At least, that is how fast death spreads across an egg cell. In multicellular animals, cells often sacrifice themselves for the greater good. First, much of the machinery inside the cell self-destructs, and then the whole cell disintegrates. Some cells undergo this programmed cell death during development – it’s how our fingers separate in the womb, for instance – while other cells trigger it to prevent cancer or to stop viruses spreading. It has been clear for a while that once programmed cell death has been initiated, the signal spreads rapidly within a cell, says James Ferrell of Stanford University in California. But no one had studied yet how it spreads. Ferrell and his colleague Xianrui Cheng have now shown that rather than some chemical signal slowly diffusing through the cell, death spreads as a “trigger wave”, with the self-destruction of one part of the cell triggering the self-destruction of the next part. Other examples of trigger waves include nerve impulses and the spread of wildfires.
8-9-18 Here’s how fast cell death can strike
Scientists have clocked the speed of a form of cellular suicide called apoptosis. Scientists now know how long it takes for a cell to tell itself it’s time to die. Signals triggering a type of cell suicide called apoptosis move through a cell like a wave, traveling at a rate of 30 micrometers per minute, Stanford University systems biologists Xianrui Cheng and James Ferrell Jr. report in the Aug. 10 Science. These findings resolve a debate over whether these death signals spread by diffusion, with signaling molecules working their own way across a cell, or as self-regenerating trigger waves, like toppling dominoes. The apoptosis process starts with damage that causes the release of death signal chemicals. One example is cytochrome c leaking from damaged mitochondria, the cell’s power plant. Once cytochrome c concentrations get high enough, the chemicals signal proteins called caspases to go to work. Caspases trigger other proteins to poke holes in neighboring mitochondria, releasing more cytochrome c and moving the death wave across the cell. That chain reaction happens more quickly than diffusion can, Ferrell says. In an African clawed frog egg, a trigger wave takes about a half-hour to spread across the 1.2 millimeter cell, whereas diffusion would take five hours, he says. Like forest fires, trigger waves will keep going as long as there is fuel to feed them — in this case, the death signal chemicals and proteins, Ferrell says. He predicts that many other biological signals may move as trigger waves.
8-9-18 A ghost gene leaves ocean mammals vulnerable to some pesticides
Manatees, for example, don't produce a protein that breaks down organophosphates. A gene that helps mammals break down certain toxic chemicals appears to be faulty in marine mammals — potentially leaving manatees, dolphins and other warm-blooded water dwellers more sensitive to dangerous pesticides. The gene, PON1, carries instructions for making a protein that interacts with fatty acids ingested with food. But that protein has taken on another role in recent decades: breaking down toxic chemicals found in a popular class of pesticides called organophosphates. As the chemicals drain from agricultural fields, they can poison waterways and coastal areas and harm wildlife, says Wynn Meyer, an evolutionary geneticist at the University of Pittsburgh. An inspection of the genetic instructions of 53 land mammal species found the gene intact. But in six marine mammal species, PON1 was riddled with mutations that made it useless, Meyer and colleagues report in the Aug. 10 Science. The gene became defunct about 64 million to 21 million years ago, possibly due to dietary or behavioral changes related to marine mammal ancestors’ move from land to sea, the researchers say.
8-9-18 A newly approved drug could be a boon for treating malaria
But people with a certain genetic mutation who use tafenoquine could be at risk of anemia. The first new treatment in 60 years for a particularly stubborn kind of malaria is raising hopes that it might help eradicate the disease, even though the treatment can cause a dangerous side effect. Called tafenoquine, the drug targets the parasite that causes relapsing malaria. Plasmodium vivax infects an estimated 8.5 million people, mainly in Asia and Latin America. Each time infected people have a malaria relapse, the parasite returns to their bloodstream, allowing them to transmit the infection if a mosquito bites them again. Tafenoquine was approved as a treatment in July by the U.S. Food and Drug Administration and is under consideration as a preventative medication, too. “This is a game changer because we’ve really been struggling with eliminating [P.] vivax,” says malaria physician Ric Price from the Menzies School of Health Research in Darwin, Australia. The FDA’s action is expected to spur other countries where relapsing malaria is more prevalent to approve the drug as well. Companies are also working to develop speedy, low-cost tests that can identify people with a genetic deficiency who may risk getting a kind of anemia from the new drug. This test is essential for putting the drug to use in rural areas where rates of both P. vivax and this deficiency can be high.
8-9-18 Allergy explosion: The truth behind the most common myths
You can grow into and out of allergies your whole life; they come in groups; women are more allergy prone... Wild ideas about allergies abound, but which should you believe?
- Are women more allergy-prone?
- In adult life, women are certainly more likely than men to report having allergies and intolerances to food. Intolerances differ from allergies, but they are often grouped together in studies.
- Can you grow into and out of allergies? Adult-onset hay fever often comes as a surprise to those newly affected – but it is true, you really can develop fresh allergies throughout your life. Just because you have never been allergic to pollen or peanuts, doesn’t mean you never will be.
- Do allergies come in groups? If you know someone who can’t eat shellfish and also complains about dust, they aren’t (necessarily) just being picky. Allergies can come in a gang, and some combinations are more common than others.
- Not an allergy Allergies are caused by the immune system unnecessarily responding to harmless molecules. But not all rashes, swellings or breathing difficulties are a sign of one. (Food intolerance, Chemical sensitivity, Nocebo effect, Rhinitis)
8-8-18 Allergy explosion: They are on the rise, and here’s why
Banning nuts on planes and in schools may seem like hysteria, but there's good reason: allergies are becoming more common. And you may not realise how you're affected If your summer months are blighted by congestion, sneezing and a runny nose, you might think your immune system has gone into overdrive, or that it is especially good at its job. But unfortunately it’s not that simple. Allergies are caused by the immune system mistakenly reacting to certain innocuous molecules from the outside world. These can be part of anything from cat skin to certain foods (see “The most common allergies”, below). Any molecule capable of doing this is called an allergen. Although allergens pose no real danger to our bodies, their structures are recognised as a threat by some people’s antibodies – immune proteins on the lookout for harmful invaders. Allergies involve a special class of antibodies called immunoglobulin E (IgE). Different IgE antibodies detect different allergens. When this happens, the antibodies trigger immune cells to release histamine and other inflammatory chemicals, leading to those nasty symptoms, which under normal circumstances would be a useful defence against invading organisms. This is a highly primed defence mechanism. IgE antibodies bind to immune cells about 1000 times more tightly than any other class of antibody. This means they are usually already attached to an immune cell, and the whole system is ready to respond as soon as an allergen is detected. This happens in seconds to minutes, while other branches of the immune system take days to respond to a cold virus, for example. “It really is a remarkable system,” says Brian Sutton of King’s College London.
8-8-18 Allergy explosion: What causes allergies and how to avoid them
We've all heard that being too clean can cause allergies, or exposure can help you beat them. Most advice doesn't stand up, but there are things that do seem to work. Cleanliness is next to godliness, as they say, so for those who are a little less fastidious, the idea that dirt could protect from allergies might have a certain appeal. First proposed in 1989 by epidemiologist David Strachan, the thinking behind this “hygiene hypothesis” was that modern life has become more hygienic, leading children to catch fewer infections. This somehow predisposes them to develop allergies, perhaps because their immune systems have been incorrectly trained. If so, allergies are the price people in developed nations pay for massively reduced infant mortality. It is an idea that caught hold with the public, but it doesn’t fully add up. We now know that childhood infections don’t seem to make you any less likely to develop allergies. And major cities like London and New York had largely cleaned up their acts by 1920 – long before the idea was put forward. Water chlorination and separate sewage systems made cholera and typhoid infections rare. And if clean living is to blame for allergies, it doesn’t make sense that it took 40 years for asthma to begin to rise. Since 1960, developed countries have seen only minor changes in hygiene, so what prompted the sudden and recent surge in food allergies?
8-8-18 Why allergies aren’t nuts at all
Faced with airline peanut bans, it’s easy to dismiss allergies as imaginary modern maladies. They’re not – and we need to understand why they’re on the up. LOVERS of nuts – and freedom – suffered a blow on 1 August, when the US budget carrier Southwest Airlines went peanut-free. While many parents of children with allergies expressed thanks, other people took to the internet to announce they would be bringing their own supply from now on. If you were born before the 1990s, or don’t have children, peanut bans by airlines, schools and workplaces can feel like a gross overreaction. Allergies may seem like modern maladies, but that does not make them any less real or life-threatening. This isn’t simply a case of hypochondria or increased vigilance – cohort studies that have closely followed different generations for decades confirm that hay fever, allergic asthma and food allergies have all risen since the mid-20th century in the developed world. Rapidly developing nations such as China are now beginning to see an increase in allergies too. The challenge is to work out why, and dispel some of the many other myths surrounding allergies (see “The allergy explosion”). In the meantime, whether afflicted or non-afflicted, we must all learn to live with them.
8-8-18 Ecstasy-like drugs might relieve social difficulties in autism
Mouse studies hint that social difficulties in autism might be caused by faulty serotonin signalling in the brain and can be helped with serotonin-boosting drugs. Mimicking the effects of the drug ecstasy seems to restore normal social behaviour in mice modified to have social difficulties. Robert Malenka at Stanford University in California and his colleagues have been studying sociability in mice, as a way to understand why some people with autism can find social situations unpleasant and confusing. They have found that mice missing a section of DNA are less interested in spending time with other mice. The equivalent region of human DNA is often missing in people with autism. When mice socialise, they usually get a rush of the feel-good chemical serotonin in the brain’s nucleus accumbens. But the modified mice don’t get this serotonin surge, which may explain why they are less interested in hanging out with other mice. To enhance serotonin activity in the nucleus accumbens of these mice, Malenka’s team stimulated specific brain cells using laser light or a drug called CP93129. These treatments were enough to make these mice become newly sociable. Similar treatments could potentially improve sociability in people with autism too, says Malenka. But although the approach is promising, it is a big leap from mice to humans, says Matthew Hale at La Trobe University in Melbourne, Australia. Modified mice only mimic certain elements of autism, like reduced social motivation, rather than the whole complex condition, he says.
8-8-18 Researchers say CRISPR edits to a human embryo worked. But critics still doubt it
Reports that a heart disease–causing version of a gene had been corrected remain contested. When researchers announced last year that they had edited human embryos to repair a damaged gene that can lead to heart failure, critics called the report into question. Now new evidence confirms that the gene editing was successful, reproductive and developmental biologist Shoukhrat Mitalipov and colleagues report August 8 in Nature. “All of our conclusions were basically right,” Mitalipov, of Oregon Health & Science University in Portland, said during a news conference on August 6. But authors of two critiques published in the same issue of Nature say they still aren’t convinced. At issue is the way that the gene was repaired. Mitalipov and colleagues used the molecular scissors CRISPR/Cas9 to cut a faulty version of a gene called MYBPC3 in sperm (SN: 9/2/17, p. 6). People who inherit this version of the gene often develop heart failure. Cutting the gene allows cells to fix the problem by replacing erroneous instructions in the gene with correct information. Researchers supplied the correct information in the form of small foreign pieces of DNA, but the embryos ignored that repair template. Instead, Mitalipov and colleagues say, embryos used a healthy version of the gene on the mother’s chromosome to fix the error. That action is called gene conversion.
8-8-18 Tight underwear really is linked to lower sperm counts in men
Men who wear boxer shorts have higher sperm levels than men who wear tight underwear, although the difference shouldn't usually be enough to affect fertility. A man’s choice of underwear really can have an impact on his sperm, according to the largest study yet on the subject. Jorge Chavarro and colleagues at Harvard University asked 656 men to provide a semen sample and blood sample, and answer a questionnaire about what type of underwear they wore most often in the previous three months. Men who wore boxer shorts had a 25 per cent higher sperm concentration, 17 per cent higher total sperm count and 33 per cent more swimming sperm in a single ejaculate than men who wore other types of underwear. Those results are after adjusting for numerous other factors that might affect the results, such as differences in age, body mass index and smoking between the groups, but it’s impossible to rule out the possibility of other confounding factors that weren’t considered. Sperm production is extremely sensitive to temperature, and requires temperatures a few degrees lower than the temperature inside the abdomen. Previous studies have shown that tight underwear can push the testes closer to the abdomen and raise the temperature inside the scrotum, says Chavarro.
8-8-18 The debate over people’s pathway into the Americas heats up.
An inland route was likely, though a coastal route was possible, researchers claim. Despite recently getting a cold shoulder from some researchers, a long-standing idea that North America’s first settlers entered the continent via an ice-free inland corridor boasts more scientific support than any other proposal, an international team says. New World colonizers from Asia may also have traveled by canoe down the Northwest Pacific Coast and perhaps much farther, as critics of the ice-free corridor hypothesis have argued. But less evidence supports that possibility, archaeologist Ben Potter of the University of Alaska Fairbanks and colleagues argue in a research review published online August 8 in Science Advances. Whatever route they took, people didn’t reach North America until after 16,000 years ago as temperatures rose near the end of the Ice Age and shoreline food sources expanded, the interdisciplinary group concludes. Widespread human occupations appeared in the Americas by about 13,500 years ago. Sites from this time were inhabited by the Clovis people, best known for long, triangular spearpoints used in hunting big game. Advocates of a primarily coastal migration, however, have suggested that shoreline-hugging seafarers entered the Americas much earlier, with some archaeological evidence putting people in South America by nearly 20,000 years ago (SN: 12/26/15, p. 10). These researchers point to a study of plant and animal DNA from ancient lake beds that indicates an interior passageway through the North American Arctic could not have provided enough food until about 12,600 years ago (SN Online: 8/10/16)
8-8-18 Why 'stealth spheres' are making you ill
A nefarious trick used by viruses to make us sick - "stealth spheres" - has been discovered by scientists. It had been thought viruses were all lone wolves, each on a solo campaign of infection. Instead they can form "packs" of up to 40 viruses and surround themselves with a fatty sphere that makes them invisible to our body's defences. The team at the US National Institutes of Health say their findings rewrite the textbooks of infection. The researchers were analysing stool samples from patients with either rotavirus or norovirus. ( Rotavirus is the biggest cause of diarrhoea in children in the world. Norovirus is so infectious it spreads rampantly through schools, care homes and frequently cruise ships.) "It blew my mind," said researcher Dr Nihal Altan-Bonnet, the head of host-pathogen dynamics at the National Heart, Lung and Blood Institute. "I had this preconceived notion... I couldn't believe it when I saw it in the stool, I just couldn't believe they'd be able to exist." The conventional view is that a virus infects a cell, which is converted into a factory for making more viruses, which burst out as individual viruses into the body. Instead some are released as groups in spheres known as vesicles. Experiments, published in the journal Cell Host and Microbe, showed the spheres gave the viruses huge advantages. (The spheres acted like an invisibility cloak that prevents the immune system spotting the viruses. The spheres protected the viruses from harsh environments including stomach acid. And they helped viruses reach their target in larger numbers and overwhelm cells in the intestines.)
8-7-18 Zika may harm nearly 1 in 7 babies exposed to the virus in the womb
A CDC study of births in U.S. territories tallies birth defects and later health problems. Babies exposed to a Zika infection while in the womb are not out of the woods even if they look healthy at birth. Nearly 1 in 10 of 1,450 babies examined developed neurological or developmental problems, such as seizures, hearing loss, impaired vision or difficulty crawling, a study from the U.S. Centers for Disease Control and Prevention finds. It’s the first tally of the health of children at least 1 year old who were born in Puerto Rico and other U.S. territories and exposed to Zika in utero. Overall, 14 percent of children exposed to Zika in the womb — about 1 in 7 — were harmed in some way by the virus, the researchers report online August 7 in Morbidity and Mortality Weekly Report. These babies were either born with a birth defect such as microcephaly — a condition in which a baby’s head is significantly smaller than it should be — or developed neurological symptoms that may be related to Zika, or both. “Congenital Zika virus infection is quite serious, even beyond just the microcephaly,” says Peter Hotez, a pediatrician and microbiologist at Baylor College of Medicine in Houston, who was not involved in the report. “We’re still getting our arms around the full neurologic spectrum of illness” that is related to Zika. The report also found that 6 percent of babies in the study had at least one birth defect caused by the virus, such as defects of the eye or brain or microcephaly (SN: 10/29/16, p. 14).
8-7-18 Football and hockey players aren’t doomed to suffer brain damage
Tests on former pro athletes’ brains shows the tissues in better shape than expected. A career of hard hits to the head doesn’t inevitably lead to brain decline, a small study of former football and hockey pros suggests. The results counter a specter raised by other studies on pro football players’ brains after death. The new findings come from extensive brain scans and behavioral tests of 21 retired athletes — football players from New York’s Buffalo Bills and hockey players from the Buffalo Sabres. In a series of papers published August 7 in the Journal of Head Trauma Rehabilitation, researchers report finding no signs among the athletes of early dementia or mental slipping. Those symptoms are early hallmarks of the brain disease chronic traumatic encephalopathy, or CTE, which can be diagnosed by a brain examination only after death. Such studies involving living subjects “are exactly what we really need,” says cognitive neuroscientist and psychologist Carrie Esopenko of Rutgers University in Newark, N.J. “They are really going to help us understand what’s going on in these lives, rather than what’s happening when they’re dead.” Using a battery of clinical tests, researchers at the University at Buffalo measured brain function and mental health, while also investigating other aspects of the ex-players’ health, such as diet, body mass index and history of drug and alcohol use. The team then compared the results with the same measures taken for 21 noncontact athletes, including runners and cyclists.
8-6-18 The truth about the suspected link between social media and self-harm
Is social media really to blame for rises in self-harming? The evidence isn’t clear, but some social media use may even be good for teenagers, says Tom Chivers. Is social media use to blame for a large growth in incidences of self-harm? That’s the conclusion some have come to, but there is no robust evidence that this is the case. In fact, some social media may even be good for teenagers. The Times today reported that hospital admissions for girls who self-harmed had gone up from 7327 in 1997 to 13,463 last year. Interviewees quoted in the piece partly blamed social media for that increase. Jon Goldin at the Royal College of Psychiatrists suggested that the fear of missing out and comparing yourself with images online could be part of the problem. But the evidence to support that claim is very uncertain. A study last year found a similar rise in self-harm among girls, especially between 2011 and 2014. However, the researchers said that part of the increase in recorded self-harming incidents is probably due to people being more willing to talk about it – perhaps due to there being less stigma. Nevertheless, the team suggested that self-harming itself is also likely to be on the rise, acknowledging that the role of social media in this trend is often discussed in the media. “People see that unhappiness in teenagers and adolescents is going up, by some measures, and that the use of technologies is going up,” says Andrew Przybylski at the Oxford Internet Institute. “The inference that’s drawn is that A is a result of B.”
8-6-18 The first detailed map of red foxes’ DNA may reveal domestication secrets
For nearly 60 years, scientists in Russia have bred tame and aggressive Vulpes vulpes. For nearly 60 years, scientists in Siberia have bred silver foxes in an attempt to replay how domestication occurred thousands of years ago. Now, in a first, researchers have compiled the genetic instruction book, or genome, of Vulpes vulpes, the red fox species that includes the silver-coated variant. This long-awaited study of the foxes’ DNA may reveal genetic changes that drove domestication of animals such as cats and dogs, the team reports online August 6 in Nature Ecology & Evolution. At the Institute of Cytology and Genetics of the Russian Academy of Sciences in Novosibirsk, Russia, researchers bred one group of foxes for ever-tamer behavior, while another group was bred for increasing aggressiveness toward humans (SN: 5/13/17, p. 29). Rif, the male silver fox whose DNA serves as the example, or reference, genome for all members of the species, was the son of an aggressive vixen and a tame male. Geneticist Anna Kukekova of the University of Illinois at Urbana-Champaign and colleagues also conducted less-detailed examinations of 30 foxes’ DNA: 10 foxes each from the tame and aggressive groups and 10 animals from a “conventional” group that hadn’t been bred for either friendliness or aggression. Those genomes are an invaluable resource for researchers studying domestication, behavioral and population genetics and even human disorders such as autism and mental illness, says Ben Sacks, a canid evolutionary geneticist at the University of California, Davis, School of Veterinary Medicine. “It makes all kinds of research possible that weren’t before,” he says.
8-6-18 It may be impossible to evolve a large brain if you hibernate
Mammals that hibernate have smaller brains than those that don’t, suggesting that hibernation limits brain size by reducing annual food intake. Mammals that hibernate for part of the year tend to have smaller brains than those that can feed all year round. The finding may help explain why big-brained primates like us mostly evolved near the equator. It may be that our species arose in Africa, rather than neighbouring Europe, because Africa lies on the equator and much of it has only weak seasons. Sandra Heldstab of the University of Zurich, Switzerland and her colleagues compiled data on 1104 mammalian species. They looked at the size of each species’ brain relative to its body, and whether or not it hibernated. Those mammals that hibernated had significantly smaller brains relative to their bodies, even when the team controlled for other factors like the animals’ diets. “Hibernation really is a constraint for brain size,” says Heldstab. The team argues that this is because it takes a lot of energy to grow and run a large brain, an idea called the “expensive brain hypothesis”. For an animal to grow a big brain, it must put less energy into something else – and if food is tight there are limits to what it can do. “If you have a seasonality in food availability, if you don’t have a constant high energy supply, you’re just not able to have a large brain,” says Heldstab.
8-3-18 Alzheimer’s breakthrough
For the first time in a major clinical trial, an experimental drug has seemingly slowed the progress of Alzheimer’s disease, reports CNN.com. The drug, BAN2401, is an antibody designed to remove amyloid, a protein that can build up in the brain and disrupt nerve cell function. The 18-month trial by U.S. biotech company Biogen and Japanese drugmaker Eisai involved 856 people with mild cognitive impairment, a sign of early-stage Alzheimer’s, or mild Alzheimer’s dementia; all had a significant buildup of the protein. While other drugs have succeeded in reducing amyloid levels, they didn’t ease memory decline or other cognitive problems. But BAN2401 reduced the development of new amyloid clusters in the brain and shrunk existing plaques by 70 percent on average. On a series of cognitive tests measuring memory and skills such as planning and reasoning, the performance of participants who took the experimental treatment declined at a rate up to 30 percent slower than that in a placebo group. Experts caution that more extensive trials of BAN2401 are needed. “It’s encouraging,” says Julie Schneider, a professor of pathology at Rush Medical College, “but I personally think there is a lot more work to be done.”
8-3-18 Alternative medicine and cancer
Cancer patients who use alternative medicine to help alleviate their symptoms have a greater risk of dying prematurely, because they are more likely to skip essential conventional treatments. That’s the conclusion of a new study by researchers at Yale University, who examined the records of 1,290 people with breast, prostate, lung, or colorectal cancer. Of these, 258 used at least one complementary medicine, such as homeopathy, Chinese herbal medicine, or naturopathy. While all the participants were using at least one conventional cancer treatment at the start of the study, 53 percent of the alternative-medicine users subsequently declined a course of radiotherapy, 34 percent refused chemotherapy, and 7 percent rejected surgery. The impact on their health was significant. Only 82 percent survived the disease after five years, compared with 87 percent of those who stuck to standard care. Overall, the alternative-medicine users were almost twice as likely to die over the 10-year study period. “There is a great deal of confusion about the role of complementary therapies,” lead author Skyler Johnson tells ScienceDaily.com. “[These findings] should give providers and patients pause.”
8-3-18 Food chemicals harming kids?
The leading U.S. pediatricians’ group has issued a stark warning about food additives and food-packaging materials, cautioning that many of the chemicals used in these products have never been properly tested and could pose a health risk to children. The American Academy of Pediatrics cited mounting scientific evidence that “direct additives,” such as artificial flavorings and colorings, as well as “indirect additives” that leak into food from plastic and other packaging may interfere with the body’s hormone system. That disruption can cause increased risk of obesity and other health problems. Children are more vulnerable to these chemicals than adults because their organs are still developing, and because “pound for pound, they eat more food,” lead author Leonardo Trasande tells HealthDay.com. The AAP identified several particularly harmful chemicals: nitrates and nitrites, which are used as preservatives, especially in meat products; phthalates and perchlorates, which appear in plastic packaging; and bisphenols, used in the lining of many metal food cans. The pediatricians’ group recommends limiting exposure to these chemicals by avoiding canned goods, using wax paper rather than plastic wrap, and never microwaving plastic containers.
8-3-18 The world’s oldest bread
For years, historians and archaeologists have believed our ancestors began baking bread only after they started farming wheat. But the discovery of a few blackened bread crumbs in Jordan suggests the reverse may be true: that early humans developed farming as a way to produce more bread. The crumbs, found in sediment samples in what was once a dwelling or ceremonial building, date back 14,400 years—about 4,000 years before the earliest evidence of agriculture. “Our work shows that bread was not a product of settled, complex societies but of a Paleolithic hunter-gatherer society,” study author Amaia Arranz Otaegui tells The Washington Post. The ancient people who built the structure, the hunter-gatherer Natufians, wouldn’t have had the pita-like bread every day; collecting enough wild grains to be ground down into flour would have been a long and arduous process. But Arranz Otaegui says if bread was “desirable or much sought after,” it may eventually have helped spur the dawn of agriculture.
8-3-18 The great Chinese dinosaur boom
In northeastern China, paleontologists are in the midst of a gold rush of fossil finding, said Richard Conniff. They have uncovered dozens of new species of dinosaurs—and are rewriting what we know about the ancient world. We were visiting a dinosaur dig, but there was also a museum under construction—steel beams riveted together to form layers, stacked one atop another, climbing a hillside in two parallel rows. The two wings connected by a central pavilion looked like a bird about to take off. The new museum—its name roughly translates as Liaoning Beipiao Sihetun Ancient Fossils Museum—is due to open sometime in 2019. It was unmistakably huge. It was also expensive (Fangfang estimated $28 million for construction alone). And it was in the middle of nowhere. We were in a rural village called Sihetun, about 250 miles northeast of Beijing. In the exuberant fashion of a lot of modern development in China, the new structure is going up in anticipation of visitors arriving by speed train from the capital, except that the speed train network hasn’t been built yet. The new museum is located at an epicenter of modern paleontological discovery, an area that is at least as rich in fossils, and in some ways as wild, as the American West during the great era of dinosaur discovery in the late 19th century. In the mid-1990s, on that hillside in Sihetun, a farmer stumbled onto the world’s first known feathered dinosaur, a creature now named Sinosauropteryx (“the China dragon bird”). Actually, the farmer found two halves of a slab, each preserving a mirror image of this dinosaur. In the freewheeling spirit that has characterized the fossil trade in the area ever since, he sold one half to one unwitting museum and one half to another. It was the start of a fossil gold rush. The region has yielded more than 40 dinosaur species to date.
8-3-18 Rat lungworm disease is popping up in the mainland United States
Experts advise everyone to wash produce carefully and not eat raw snails or slugs. Health officials have confirmed 12 cases of rat lungworm disease in the continental United States since January 2011 — including six patients who had not traveled abroad but still contracted the illness caused by a parasite endemic to tropical regions in Asia and Hawaii. While the disease can be mild, it can become extreme and cause severe neurological problems. In most of the new cases, patients complained of headache, fever, weakness and symptoms consistent with meningitis, the U.S. Centers for Disease Control and Prevention reports in the Aug. 3 Morbidity and Mortality Weekly Report. The disease is also known as angiostrongyliasis, after the parasitic roundworm Angiostrongylus cantonensis whose larvae hatch in the lungs of rats and then are expelled in the rodents’ excrement. At that point, the larvae can be picked up by snails and slugs, and then passed along to humans if the snails and slugs are eaten raw. On July 30, researchers added centipedes to the list of creatures that can transmit the disease to humans, after a Chinese woman and her son contracted the disease in 2012 after eating raw centipedes bought at a market (SN Online: 7/30/18). More than half of the recent U.S. cases involved patients who had eaten raw vegetables, likely inadvertently consuming a snail or slug, and at least one case involved a toddler who ate slugs while playing. Of the six cases confirmed as originating within the country, four were reported from Texas, one from Tennessee and one from Alabama.
8-3-18 Engineered pig lung transplant 'a success'
Scientists have successfully transplanted a bioengineered lung into a pig. To create a new lung, experts used a "scaffold" that provided structural support and slowly built up the lung tissue around it, using cells from the pig that was due to get the transplant. This was done to prevent the lung being rejected by the pig's immune system. Once transplanted, the lung alveolar tissue and blood vessels carried on developing for up to two months. Not only was the lung not rejected, but it even developed an important population of bacteria. Lungs suitable for transplant are in short supply and the study is a significant step forward in finding an alternative solution. "People wait for a long time on a transplant list before they are able to receive a donated lung," said co-author Professor Joan Nichols. The transplantation of bioengineered lungs has been tried before in small animals, but these efforts have met with failure. There were problems with the blood vessels and the animals suffered from an accumulation of fluid, known as oedema. "We were able to make a much better developed vasculature in the lungs... and transplant into a larger animal with a larger lung," said co-author Prof Joaquin Cortiella, from the University of Texas Medical Branch (UTMB) in Galveston, US.
8-3-18 The ‘language gene’ didn’t give humans a big leg up in evolution
The effects of genetic tweaks to FOXP2 have been debated for years. Humans’ gift of gab probably wasn’t the evolutionary boon that scientists once thought. There’s no evidence that FOXP2, sometimes called “the language gene,” gave humans such a big evolutionary advantage that it was quickly adopted across the species, what scientists call a selective sweep. That finding, reported online August 2 in Cell, follows years of debate about the role of FOXP2 in human evolution. In 2002, the gene became famous when researchers thought they had found evidence that a tweak in FOXP2 spread quickly to all humans — and only humans — about 200,000 years ago. That tweak swapped two amino acids in the human version of the gene for ones different than in other animals’ versions of the gene. FOXP2 is involved in vocal learning in songbirds, and people with mutations in the gene have speech and language problems. Many researchers initially thought that the amino acid swap was what enabled humans to speak. Speech would have given humans a leg up on competition from Neandertals and other ancient hominids. That view helped make FOXP2 a textbook example of selective sweeps. Some researchers even suggested that FOXP2 was the gene that defines humans, until it became clear that the gene did not allow humans to settle the world and replace other hominids, says archeaogeneticist Johannes Krause at the Max Planck Institute for the Science of Human History in Jena, Germany, who was not involved in the study. “It was not the one gene to rule them all.”
8-2-18 Indonesia’s pygmies didn’t descend from hobbits, DNA analysis suggests
The Rampasasa live on Flores where hobbit fossils were found, but don’t share a genetic history. obbits took a separate evolutionary path to becoming small than did short, modern-day humans living on the same Indonesian island, a new DNA analysis suggests. Rampasasa pygmies residing near a cave on Flores that previously yielded small-bodied hobbit fossils inherited DNA from Neandertals and Denisovans but not from any other now-extinct hominid, scientists say, an international team reports in the Aug. 3 Science. The finding provides genetic backup for a fossil-based argument portraying these controversial Stone Age hominids as a separate species, Homo floresiensis, not small-bodied Homo sapiens that could have represented ancestors of Rampasasa people. Diminutive hobbits, standing roughly a meter tall, lived on Flores from at least 100,000 to 60,000 years ago, with possible ancestors on the island dating to about 700,000 years ago (SN: 7/9/16, p. 6). Some scientists contend that hobbits were actually short humans, not an ancient hominid species (SN: 11/18/06, p. 330). So far, researchers have been unable to extract DNA from hobbit fossils. Comparing hobbit and present-day human DNA would go a long way toward clarifying the evolutionary ID of the half-size Flores hominids.
8-2-18 Small height evolved twice on 'Hobbit' island of Flores
A new study has shown that small height evolved twice in humans on the Indonesian island of Flores. Scientists decoded the DNA of modern-day "pygmy" people to find out if they might be partly descended from the extinct Hobbit species. The remains of these Hobbits were found during an archaeological dig on Flores 15 years ago. The new analysis, published in the journal Science, found no trace of the Hobbit's DNA in the present-day people. This is important because some scientists had wondered whether modern humans (Homo sapiens) could have mixed with the Hobbit population when they first arrived on the island thousands of years ago. In theory, this could have led to Hobbit genes being passed down into living people on the island. Although the finding excludes that idea, it may help to explain why evolution may favour small size on islands. The fossilised remains of a small human species Homo floresiensis, nicknamed the "Hobbit", caused a sensation when they were found in Liang Bua cave. Just over metre in height, this human relative lived on Flores before our species got there. It's thought to have gone extinct tens of thousands of years ago. While there has been considerable research - and controversy - on the subject of the Hobbit, the evolutionary origins of living pygmy people - who also typically show small stature - have not been well studied. The new analysis showed that the Flores pygmies are not significantly distinct, genetically-speaking, from other populations around the world. Like some other humans in the same region, the pygmies have inherited part of their DNA code from both Neanderthals and another type of early human, the Denisovans.
8-2-18 'Oldest library in Germany' unearthed by Cologne archaeologist
Archaeologists in Cologne believe they have uncovered the foundations of the oldest known library in Germany, dating back to the 2nd Century. A team from the city's Roman-Germanic Museum discovered the library remains while excavating the site of a Protestant church. The building likely housed up to 20,000 scrolls, according to Dr Dirk Schmitz, a researcher on the expedition. He described the find as "truly spectacular". The archaeologists involved in the parish church project uncovered the remains of a Roman building from the 2nd Century. Cologne was founded by the Romans under the name Colonia in 50 AD. The former library is thought to have had a size of around 20 metres by nine and was two storeys high. "At first we thought they were the remains of a space for public gatherings," Marcus Trier, director of the city's Romano-Germanic Museum said, but the walls had "unusual, cavernous structures". After intensive research and comparison with ancient buildings such as the Ephesus in Turkey, the archaeologists were confident they had found the remains of what used to be a library.
8-2-18 Did ancient Mayan civilisation collapse because of a sudden drought?
We have the best evidence yet that there was a prolonged drought at the time of the demise of the classic Mayan civilisation - and could explain why it collapsed. Up to around 750 AD, the Mayan civilisation was thriving. Dozens of new monuments were being built every year in what is now Mexico and central America. But by 900 monument building ceased altogether and some cities in the southern lowlands were abandoned. What happened? One idea is that a prolonged drought was to blame, and now we have the best evidence yet that this was the case. Analysis of “fossil water” has shown that there was half as much rain as usual between 800 and 1000, and that at times during this period there was 70 per cent less rainfall. During prolonged dry periods gypsum may precipitate out of lake waters and be deposited in sediments. The presence of gypsum deposits in Lake Chichancanab in Mexico provided the first evidence of prolonged droughts around the time of the Mayan decline. But just how severe were these droughts? To find out, Nicholas Evans at the University of Cambridge, UK, and colleagues extracted ancient water trapped in the gypsum and analysed its isotopic ratios. Water molecules that contain, say, an oxygen-17 atom instead of the more common oxygen-16 are heavier and less like to evaporate. Heavier water molecules therefore accumulate in the lake during times of low rainfall and high evaporation.
8-2-18 Fossil teeth show how a mass extinction scrambled shark evolution.
The dinosaur-destroying event flipped which sharks were most dominant in the oceans. The extinction event that wiped out all nonbird dinosaurs about 66 million years ago also shook up shark evolution. Fossilized shark teeth show that the extinction marked a shift in the relative fates of two groups of sharks. Apex predators called lamniformes, which include modern great white sharks, dominated the oceans before the event, which took place at the end of the Cretaceous Period. But afterward, midlevel predator sharks called carcharhiniformes came to dominate the waters — as they still do today, researchers report August 2 in Current Biology. Paleontologist Mohamad Bazzi of Uppsala University in Sweden and colleagues examined the shapes of nearly 600 shark teeth dating from 72 million to 56 million years ago. Unlike their cartilaginous skeletons, sharks’ teeth, which the fish shed throughout their lives, are well preserved in the fossil record, Bazzi says. By looking at patterns in tooth shape variation — the height of the crown or the breadth of the tooth — scientists can measure trends in shark diversity. After the extinction event, lamniform sharks that had a particular tooth shape — low-crowned and triangular — appeared to decline, while carcharhiniform sharks with the same low-crowned tooth shape proliferated. The extinction “is one of the more transformative events in shark evolution,” Bazzi says. Today, there are only 15 known species of lamniformes, but hundreds of carcharhiniformes, including hammerheads and lemon sharks.
8-2-18 Google Glass app uses emojis to help children with autism read faces
Many children with autism find it hard to decipher other people’s facial expressions. An interactive system that uses Google Glass may help. Many children diagnosed with autism find it hard to decipher other people’s facial expressions. An interactive system that uses Google Glass may help them out. “I can see the difference this will have in people’s lives in a significant, immediate and meaningful way,” says Donji Cullenbine, whose child took part in the study. She said enrolling on the study was “one of the best choices that I have ever made for him”. Using technology such as Google Glass to support individuals with autism has been a promising area of research. The idea is they can provide a game-like environment to practise life skills without being overwhelming. But it has never been used outside the lab before. Dennis Wall at the Stanford University School of Medicine and his colleagues have now demonstrated that the effects work outside of the lab. They gave 14 children with autism a system called Superpower Glass to try at home for an average of 10 weeks each.
8-2-18 Google Glass could help children with autism socialize with others
The high-tech accessory is teaching kids to read facial expressions, a pilot trial suggests. Google Glass may have failed as a high-tech fashion trend, but it’s showing promise as a tool to help children with autism better navigate social situations. A new smartphone app that pairs with a Google Glass headset uses facial recognition software to give the wearer real-time updates on which emotions people are expressing. In a pilot trial, described online August 2 in npj Digital Medicine, 14 children with autism spectrum disorder used this program at home for an average of just over 10 weeks. After treatment, the kids showed improved social skills, including increased eye contact and ability to decode facial expressions. After her 9-year-old son, Alex, participated in the study, Donji Cullenbine described the Google Glass therapy as “remarkable.” She noticed within a few weeks that Alex was meeting her eyes more often — a behavior change that’s stuck since treatment ended, she says. And Alex enjoyed using the Google Glass app. Cullenbine recalls her son telling her excitedly, “Mommy, I can read minds.” Unlike most children, who naturally learn to read facial expressions by interacting with family and friends, children with autism often have to hone these skills through behavioral therapy. That typically involves a therapist leading the child through structured activities, like exercises with flash cards that depict faces wearing different expressions. But therapists are so few and far between that a child diagnosed with autism can spend 18 months on a waiting list before starting treatment.
8-2-18 Mystery of Welsh bodies buried at Stonehenge as first stones arrived
A new analysis of the cremated remains at Stonehenge suggest that some of the bodies buried there came from hundreds of kilometres away in Wales. Some of the bodies buried at Stonehenge came from hundreds of kilometres away in Wales, a new analysis of their cremated remains has found. Fragments of bones from burials at the site in Wiltshire, UK, were first uncovered almost 100 years ago. Until now, it was assumed they were all individuals from the local area. Radiocarbon dating of the remains had suggested that they were buried at around the same time as the first standing stones – Welsh bluestones – were erected at the site, around 3000 BC. Now, new developments in a technique known as strontium isotopic analysis have allowed Christophe Snoeck and his team from Vrije Universiteit Brussel to study the remains again. Their work suggests the individuals came from the same area as the bluestones. Strontium isotopic analysis can tell researchers what foods someone was predominantly eating in the last decade before they died. Plants have different levels of strontium depending on the bedrock of the area they are grown in, and this can be read in the bones of the humans who eat them.
8-2-18 Cremated remains reveal hints of who is buried at Stonehenge
Chemical analyses of skull pieces suggest some of the dead came from Wales. Stonehenge attracted the dead from far beyond its location in southern England. A new analysis of cremated human remains interred at the iconic site between around 5,000 and 4,400 years ago provides the first glimpse of who was buried there. Some were outsiders who probably spent the last decade or so of their lives in what’s now West Wales, more than 200 kilometers west of Stonehenge, researchers report August 2 in Scientific Reports. West Wales was the source of rocks known as bluestones used in early stages of constructing Stonehenge. Bluestones are smaller than the ancient monument’s massive sandstone boulders. The new investigation “adds detail to a previously rather shaky framework” of archaeological finds suggesting that links existed among ancient societies across southern England and Wales, says archaeologist Timothy Darvill of Bournemouth University in Poole, England, who was not involved in the research. Geographic origins of cremated remains at the site had previously eluded scientists. In the new study, bioarchaeologist Christophe Snoeck of Vrije Universiteit Brussel in Belgium and colleagues analyzed two forms of the element strontium in human skull fragments that were previously found among cremated remains at Stonehenge to narrow down individuals’ origins. Signature levels of these strontium types characterize rock formations and soil in different regions. Humans and other animals incorporate strontium into their bones and teeth by eating plants.
8-2-18 Stonehenge: First residents from west Wales
Researchers have shown that cremated humans at Stonehenge were from the same region of Wales as the stones used in construction. The key question was to understand the geographic origin of the people buried at Stonehenge. The key innovation was finding that high temperatures of cremation can crystallise a skull, locking in the chemical signal of its origin. The findings have been published in the journal Scientific Reports. The first long-term residents of Stonehenge, along with the first stones, arrived about 5,000 years ago. While it is already known that the "bluestones" that were first used to build Stonehenge were transported from 150 miles (240 km) away in modern-day Pembrokeshire, almost nothing is known about the people involved. The scientists' work shows that both people and materials were moving between the regions and that, for some of these people, the move was permanent. When their lives ended, their cremated remains were placed under the ancient monument in what is now Wiltshire. Lead author Dr Christophe Snoeck compared the levels of different forms, or isotopes, of the element strontium against a national database to work out where the cremated individuals spent the last years of their lives.
8-1-18 Bio-engineered lungs are the first successful organs made in the lab
Pigs have been able to breathe using lungs made in the lab. This is the most successful complex organ to be bioengineered yet – but there’s one big step left. In a major landmark for bioengineering, lungs that were made in the lab have been successfully implanted into pigs for the first time, enabling them to breathe normally. They have not yet been hooked up to a crucial artery, but the team behind the work are hopeful. “I would argue this is the first time that a tissue-engineered organ has been implanted in a large animal and shown to survive and have any degree of function whatsoever,” says Laura Niklason at Yale University, who was not involved in the work. To make these lungs, Joan Nichols and Joaquin Cortiella at the University of Texas Medical Branch at Galveston used growth hormones to encourage pig lung cells to grow into tissue, populating a de-cellularised pig lung. When you de-cellularise an organ, you’re left with a kind of skeleton. The airways throughout the lungs branch 23 times and end in small, grape-like air sacs just 200 microns across. These globules mediate the transfer of oxygen and carbon dioxide into and out of your blood. In lungs, a scaffold of collagen and elastin proteins remains after decellularisation. “The collagen makes it strong so you can breathe for your whole life, and the elastin makes it stretch so you can breathe in and out,” Nichols says.
8-1-18 Newly-discovered type of lung cell has central role in cystic fibrosis
A new type of lung cell is rare in our bodies, but is the main place where the gene involved in the common hereditary condition cystic fibrosis is active. A completely new type of cell has been discovered in the human airway, and it may have a central role in the common genetic disorder cystic fibrosis. The discovery came out of a census of all the cells in the windpipe and lungs, led by Allon Klein at Harvard Medical School and Aron Jaffe at the pharamaceutical company Novartis. They analysed gene activity in epithelial cells – which line membranes – taken from human lungs and the trachea of mice. They found a specialised kind of epithelial cell in the lining of the trachea, which they named a pulmonary ionocyte. Its gene activity is similar to ionocytes that have been studied in frog skin and fish gills, where they move ions to regulate the pH of the liquid layer next to them. “This may be the function of the pulmonary ionocyte as well, but we don’t know yet,” says Jaffe. These new cells make up less than 2 per cent of all the cells in the airway epithelium, but they seem to be the main cell type where the gene involved in cystic fibrosis acts. This gene, called CFTR, makes a protein channel that lets certain ions move in or out of a cell.
8-1-18 Newfound airway cells may breathe life into tackling cystic fibrosis
Pulmonary ionocytes are rare cells, but play a big role in keeping lungs clear. Meet the ionocyte. This newly discovered cell may be the star of future cystic fibrosis therapies. Researchers have found that the gene tied to the disease is very active in the cells, which line the air passages of the lungs. While the cells are rare, making up only 1 to 2 percent of cells that line the airways, they seem to play an outsized role in keeping lungs clear. The identification of the ionocyte “provides key information for targeting treatments,” says medical geneticist Garry Cutting of Johns Hopkins School of Medicine in Baltimore, who was not involved in the research. Two teams, working independently, each describe the new cell online August 1 in Nature. The ionocyte shares its name with similar cells found in fish gills and frog skin. This type of cell regulates fluid movement at surfaces — skin, gills, airways — where air and water meet. In people, special proteins that tunnel across cell membranes lining the airways allow chloride ions (half of what makes salt) to move into the airway. This causes water to move into the airway through a different channel to moisten mucus along the lining, which helps it remove bacteria and inhaled particles from the body. The tunnel protein that allows chloride ions through is made by a gene called CFTR. In cystic fibrosis patients, that gene is flawed. Airways can’t regulate water movement properly and get clogged with thick mucus that traps bacteria and leads to persistent infections and lung damage. The genetic disease affects at least 70,000 people worldwide, according to the Cystic Fibrosis Foundation in Bethesda, Md.
8-1-18 One drink a day might be enough to stop dementia by flushing the brain
Light drinking helps prevent dementia, and now we may know why: it revs up the brain’s waste disposal system. LIGHT drinking helps prevent dementia, and now we may know why: it revs up the brain’s waste disposal system. Brain cells are surrounded by a network of ultra-thin tubes that flush toxins and cell waste products away. Work in mice shows that low levels of alcohol stimulate this system, while higher amounts hinder it. If the findings apply to people, the low levels would be equivalent to about two units of alcohol a day, which is about a pint of beer or a medium glass of wine. Alcohol has been getting a bad press lately. Excessive drinking causes liver damage and has been linked with several kinds of cancer. In the UK, the recommendation for how much it is safe to drink has been cut, with both men and women advised to stick to 14 units or fewer a week. The latest UK government report said even drinking at very low levels carries some risk. However, this relates to a slightly higher rate of cancers that are fairly rare – such as those of the oesophagus. When it comes to more common conditions, such as dementia, total abstention from alcohol carries a slightly higher risk than low to moderate drinking. But it was unclear why. The reason may be the brain’s waste disposal system, known as the glymphatic system, which was only discovered in 2012. We know it ramps up its activity during sleep. Among the toxins it clears is a protein called beta-amyloid, which makes up the sticky plaques found in the brains of people with Alzheimer’s disease. Some studies have suggested that long-term sleep disruption may contribute to Alzheimer’s by causing amyloid build-up.
8-1-18 AI camera to help spot the best grapes for making pesticide-free wine
A combination of AI and photography is helping wine makers keep their grapes free of disease, by spotting the grapes that are most resistant to rot. A combination of AI and photography is helping wine makers keep their grapes free of disease. Botrytis cinerea is a fungus—also known as grey rot—which has spores that pierce and infect wine grapes, causing them to shrivel and sweeten. It can add complexity and longevity to sweet wines, like Sauternes; in these cases it is known as “Noble Rot”. But it is a problem for producers of dry reds, for example, causing widespread losses of harvest in many wine regions—particularly the more humid ones where the rot proliferates. Pesticides are the most common defence. Though an environmentally-kinder method is to find and then cultivate grapes that have a natural resilience. “Part of the armoury a grape possesses against Botrytis is a good bloom of epicuticular wax,” says wine expert Demetri Walters. But manually checking the wax coverage of grapes is laborious, time consuming and subject to human error. So a team at the University of Bonn and the Julius Kühn-Institut in Germany created a mobile laboratory to automate and accelerate the process. Grapes are placed under a light, before a series of high-resolution photos are taken that pick up patterns of scattered light—including the diffuse reflections given off by the roughness of the wax. The pictures are then analysed by two AI algorithms: one singles out the grape in the image; the other determines the distribution of waxiness over the grapes.
Total Page Views
73 Evolution News Articles
for August 2018
Evolution News Articles for July 2018