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68 Evolution News Articles
for September 2019
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9-18-19 Air pollution can reach the placenta around a developing baby
A study of women in Belgium found black carbon particles, or soot, within the organ. Breathing in polluted air may send soot far beyond a pregnant woman’s lungs, all the way to the womb surrounding her developing baby. Samples of placenta collected after women in Belgium gave birth revealed soot, or black carbon, embedded within the tissue on the side that faces the baby, researchers report online September 17 in Nature Communications. The amount of black carbon in the placenta correlated with a woman’s air pollution exposure, estimated based on emissions of black carbon near her home. “There’s no doubt that air pollution harms a developing baby,” says Amy Kalkbrenner, an environmental epidemiologist at the University of Wisconsin–Milwaukee who was not involved in the new work. Mothers who encounter air pollution regularly may have babies born prematurely or with low birth weight (SN: 5/13/15). These developmental problems have been tied to an inflammatory response to air pollution in a mother’s body, including inflammation within the uterus. But the new study, Kalkbrenner says, suggests that “air pollution itself is getting into the developing baby.” The study looked particularly at black carbon, a pollutant emitted in the burning of fossil fuels such as gasoline, diesel and coal. Researchers in Belgium at Hasselt University in Diepenbeek and Katholieke Universiteit Leuven used femtosecond pulsed laser illumination to test the tissue for soot. The technique involves using extremely fast laser bursts — each one-quadrillionth of a second — to excite electrons within the tissue, which then emits light. Different tissues are known to generate certain colors, such as red for collagen and green for placental cells. The black carbon was distinct and released white light.

9-18-19 Creating human-like consciousness requires just four key ingredients
Far from being a mystical “ghost in the machine”, consciousness evolved as a practical mental tool and we could engineer it in a robot using these simple guidelines. CONSCIOUSNESS is a slippery concept. It isn’t just the stuff in your head. It is the subjective experience of some of that stuff. When you stub your toe, your brain doesn’t merely process information and trigger a reaction: you have a feeling of pain. When you are happy, you experience joy. The ethereal nature of experience is the mystery at the heart of consciousness. How does the brain, a physical object, generate a non-physical essence? This experience-ness explains why pinning down consciousness has been described as “the hard problem”. Subjective experience doesn’t exist in any physical dimension. You can’t push it and measure a reaction force, scratch it and measure its hardness or put it on a scale and measure its weight. Philosophers have described it as the “ghost in the machine”. Even scientific ideas about consciousness often have an aura of the metaphysical. Many scientists describe it as an illusion, while others see it as so fundamental that it doesn’t have an explanation. Always at the centre of the riddle lies its non-physicality. But what if consciousness isn’t so mystical after all? Perhaps we have just been asking the wrong question. Instead of trying to grapple with the hard problem, my colleagues and I at Princeton University take a more down-to-earth approach. My background lies in the neuroscience of movement control, what you could call the robotics of the brain. Drawing on that, I suggest that consciousness can be understood best from an engineering perspective. Far from being some sort of magical property, it is a tool of extraordinary power. It is a tool that can be engineered into machines. Our new approach shows how.

9-18-19 Whales evolved large brains in the same way that we did
The largest brains ever to have evolved belong to whales. Now we have discovered that the marine mammals gained their big brains size in the same way we did – through massive expansion of two particular brain regions, fuelled perhaps through changes in diet. Amandine Muller at the University of Cambridge and Stephen Montgomery at the University of Bristol, UK, looked at brain size data from 18 species of whale and dolphin, as well as from 124 different land animals including 43 species of primate. With few exceptions, the whales, dolphins and primates all seem to have gained large brains through dramatic growth of the same two brain regions: the cerebellum and neocortex. Both regions are important for cognitive functions such as attention, and for controlling the movement of the body. It makes sense that the cerebellum and neocortex evolve in unison, says Montgomery, because they are physically connected by many brain pathways. “It’s possible one can only change so much without being constrained by the performance of its partner, and needing the other structure to ‘catch up’,” he says. But what drove these two brain regions to expand so dramatically in whales and dolphins? Muller and Montgomery first explored whether the trigger was a change in social behaviour. In common with some primates – including our species – whales and dolphins can form complex social groups. However, the two researchers found no strong correlation between the whale and dolphin species with the most advanced social behaviour and those with a particularly large cerebellum and neocortex. But they did discover that the whale and dolphin species with a larger cerebellum and neocortex typically enjoy an unusually broad diet, in terms of the variety of foodstuffs they consume. This might suggest that broadening the diet encouraged the evolution of larger brains.

9-18-19 Radio waves from electric devices may affect the body clock of insects
Weak radio frequency fields seem to affect the body clocks of cockroaches. If the finding is confirmed, it could mean that weak radio waves – which are already known to disorient birds – are capable of affecting a wide range of animals. However, Martin Vacha of Masaryk University in the Czech Republic, who conducted the study, says he is “very cautious” about his team’s results. In normal conditions, there might not be any effect on insects, he says, and the team isn’t making any claims about possible effects on people. Other scientists are sceptical, and say the study needs to be independently confirmed. Many claims have been made about possible effects of electromagnetic fields on humans and other animals. In particular, it is been claimed that the radio waves from mobile phones could cause cancer. But radio waves are much less energetic than, say, X-rays and don’t cause the damage to DNA that leads to cancer. Nonetheless, some researchers think they could have more subtle effects on living tissue. A couple of recent studies, for instance, have suggested that static magnetic fields affect the body clock of fruit flies. Vacha and his colleagues decided to look at whether they affect cockroaches too. His team kept cockroaches in constant dim UV light, with no clues as to whether it was night or day, and measured the animals’ activity using image analysis software. From that they worked out what time their body clocks were keeping. When they exposed the animals to either static magnetic fields or weak radio frequency broadband noise, the cockroaches’ periods of activity became an hour or two longer. In other words, their body clocks were running more slowly. Vacha says the team tested frequencies much lower than those from mobile phones. But many electric devices, such as computers, produce this kind of broadband noise.

9-18-19 Frogs evolved to be more scared after mongooses came to their island
The Amami tip-nosed frog is a battle-worn survivor of an invasion of mongooses on its island home. The mongooses left their mark on the species, leaving the frogs more skittish towards potential threats. Small Indian mongooses (Herpestes auropunctatus) were introduced to Japan’s Amami Island in 1979 to control the islands’ rat and pit viper populations. A handful spread out from a single starting point, eventually multiplying to 6000 individuals and infiltrating much of the forested island. They preyed on – and dramatically reduced – populations of native wildlife like the Amami tip-nosed frog (Odorrana amamiensis). Following a 20-year eradication campaign, most of the mongooses have now been removed and the frogs have rebounded. The situation was a great opportunity to see if the invaders influenced the frogs’ evolution, says Hirotaka Komine at the Tokyo University of Agriculture and Technology. Komine and his team searched the island for frogs. When they spotted one, they would approach and record how close they could get before the amphibian hopped away. They found that in places with greater impact from the mongoose invasion, frogs bounded away from potential threats quicker than frogs from less affected areas. The results suggest that the frogs evolved a heightened wariness in the wake of the invasion and this fear has persisted even after mongoose eradication, says Komine. The mongoose density on the island has been extremely low for at least five years, and the maximum lifespan of a tip-nosed frog is three years, so the frogs that were tested have probably never seen a mongoose. This means the skittishness is probably a genetic change, not a learned behaviour. This amplified fear may influence the island’s local ecology because it could change how the frogs acquire their own prey. Komine thinks the fearfulness may fade over time, though.

9-17-19 Wild wheat genetics offer climate hope for food crops
Wild relatives of food crops, such as wheat, host an abundant array of genetic material to help the plants cope with a changing climate. In a study over 28 years showed that populations of wild wheat developed "beneficial mutations" such as a tolerance to temperature increases. Researchers say the results improve our understanding of how plants are responding to a warming world. The findings appear in the Proceedings of the National Academy of Sciences. "We get some very exciting results," explained lead author Yong-Bi Fu, a research scientist from Agriculture and Agri-Food Canada. "One of which is that we can demonstrate that over 28 years, and 28 generations, you can see the wild relative of the plant accumulate more genetic mutations, and we found that most of the population is still adaptable." Although the team did find that there were individual specimens in the study that did not survive the conditions associated with a warmer environment, there were others that were able to adapt in such a way that meant they could cope with a warmer world. The study involved 10 populations of emmer wheat in Israel. Dr Fu say that the temperature increase over the three decades amounted to up to two degrees Celsius, which is similar to the increase that the Paris Climate Agreement hopes to limit global average temperatures from rising above pre-industrial levels. "That is really exciting because it means that the population is able to get beneficial mutations," Dr Fu told BBC News. "This mutation is crucial, and we can see that we need a lot of effort to protect and conserve the crop's diversity in the wild, natural population." The team suggested that this insight helped to improve our knowledge of how plants could adapt to future climate change. Dr Fu also highlighted the work of UK scientists who, reporting in Nature Biotechnology, who were developing ways to clone disease-resistance (R) genes from wild relatives in order to engineer broad-spectrum resistance in domesticated crops. He said that a similar approach could be used to clone climate-resistant genes from the plants' wild relatives in order to make our food crops more climate resilient.

9-17-19 Sim Singhrao on the secrets of a healthy mind at New Scientist Live
News about our microbiome and how it affects our health is everywhere. At New Scientist Live next month, biologist Sim Singhrao will delve into this topic, focusing on how our lifestyles can lead to changes in the communities of microbes in our mouths and how these changes might diminish our general wellbeing and potentially lead to diseases like Alzheimer’s. Based at the University of Central Lancashire, Singhrao’s goal is to discover causative links between oral health and the development of Alzheimer’s disease. Ultimately, she is hoping to find strategies we can use to delay or prevent the disease.

9-17-19 A new book shows how not to fall for dubious statistics
‘The Art of Statistics’ shows how to think critically about numbers and data analyses. There are, as the saying goes, three kinds of lies: lies, damned lies and statistics. David Spiegelhalter is here to keep you from being duped by data. If you’re seeking a plain-language intro to statistics, or just want to get better at judging the reliability of numbers in the news, Spiegelhalter’s The Art of Statistics is a solid crash course. The book is less about learning how to use specific mathematical tools than it is about exploring the myriad ways statistics can help solve real-world problems — and why statistical claims often have to be padded with caveats. Spiegelhalter, a statistician at the University of Cambridge, keeps things lively by tying new concepts to questions. For instance, should you fret that eating bacon will increase your risk of bowel cancer? The relative risk might make you think so: People who eat a bacon sandwich every day have an 18 percent higher risk of bowel cancer than those who don’t. But looking at the absolute risk — a rise of 6 to 7 cases per 100 people — may put your mind at ease. Spiegelhalter’s narration is encouraging, and he knows where beginners are likely to get tripped up. He makes dense sections easier to parse by including frequent recaps and lots of data visualizations, and tucking equations into footnotes. The Art of Statistics is alight with his enthusiasm for how statistics can be used to glean information for court cases, city planning and a host of other sectors. But Spiegelhalter warns readers not to forget the assumptions and uncertainties inherent in any analysis, and tells many cautionary tales about the ways statistics can go astray. Patchy samples and logical missteps can lead to faulty conclusions.

9-17-19 How circling the globe has evolved in the 500 years since Magellan’s famous trip
Botanist Jeanne Baret and journalist Nellie Bly are two women who duplicated the feat. Half of a millennium ago, Portuguese explorer Ferdinand Magellan and his crew embarked on the first voyage to successfully sail around the world. On September 20, 1519, Magellan’s five-ship fleet set sail from Spain and traveled south, crossing the Atlantic to South America. There, the sailors happened upon a channel, later dubbed the Strait of Magellan, to the Pacific Ocean, and the ships continued west. The journey was anything but smooth sailing. Magellan dealt with shipwrecks, mutiny and conflicts with indigenous people. He was killed during such a conflict in the Philippines in 1521. But his crew carried on, traversing the Indian Ocean and hooking around Africa’s southern tip to sail north back to Spain. A lone ship docked in Seville in 1522. In the 500 years since Magellan, humankind has found new ways to circle the globe. The goal of many early circumnavigations was to connect the world, says Jeremy Kinney, chair of the aeronautics department at the Smithsonian Air and Space Museum in Washington, D.C. Circumnavigation is the ultimate expression of “humans’ ability to conquer nature and geographic boundaries,” he says. 1. In late 1774 or early 1775, French botanist and explorer Jeanne Baret became the first woman to circumnavigate the world (SN: 2/8/14). 2. November will mark another circumnavigation milestone: 130 years since American journalist Nellie Bly’s 1889 record-breaking journey. 3. A 1924 series of flights by the United States Army Air Service (which later became the Air Force) is largely considered the first global circumnavigation by plane. 4. Part of the Soviet Union’s Space Race victory, cosmonaut Yuri Gagarin became the first person in space and the first to orbit Earth (SN: 4/22/61). 5. In 2017, French sailor Francis Joyon and his crew set a new fastest record for sailing around the world.

9-16-19 Vikings probably hunted Iceland's walruses to extinction for ivory
Iceland was once home to a unique subspecies of walrus, but the animals had vanished by the mid-14th century, just 500 years after the arrival of Norse settlers. The discovery suggests hunters were responsible for the walrus’s disappearance, providing some of the clearest evidence so far that humans began driving marine mammals extinct earlier than generally thought. Researchers have known for years that walruses once lived on Iceland, but opinion has been divided on whether they vanished before or after humans arrived. To settle the debate, Tange Olsen and Xénia Keighley at the University of Copenhagen in Denmark carbon dated the remains of 34 walruses found in western Iceland. Three of the walruses died after the year 874 – the date permanent settlers are thought to have reached Iceland – with the youngest dating to between 1213 and 1330. In other words, Icelandic walruses survived for a few centuries after humans arrived. A walrus hunt is described in one late 12th century Icelandic saga: the walrus’s skull and tusks are said to have been sent to Canterbury in the UK to honour the archbishop, Thomas Becket, who was murdered in the city’s cathedral in 1170. The new data indicate the walrus in question could have been local to Iceland and not simply a migrant animal visiting the island from elsewhere. Partly because of such Medieval accounts of hunting, and because we know walrus ivory was a valuable commodity at the time, Olsen and Keighley suspect that the settlers were responsible for the disappearance of Iceland’s walruses. But they also considered an alternative hypothesis: the animals might have fled the island when people arrived, as has happened elsewhere in the North Atlantic. “When hunters went to Svalbard, the females and calves moved away,” says Keighley. But she says the new study suggests this isn’t what happened.

9-15-19 A network in the brain is involved in a range of mental health issues
Depression, schizophrenia and some other mental health conditions can have very different symptoms but they all seem to be connected by a set of structures in the brain. This network may help us understand the link between certain genes and psychiatric symptoms, and suggests a focus on symptoms, rather than categorising mental health conditions, may be a better way to help people. “We know for psychiatric illnesses, the categories of diagnosis are not very reliable,” says Maxime Taquet at the University of Oxford. Psychiatric conditions have been shown to overlap when it comes to which genes they are linked to, as well as symptoms. Taquet and his colleagues wanted to find out how these shared genetic factors might influence a person’s brain structure. Looking at the brains of adults with established disorders might not answer the question, says Taquet, as the disorder or any treatments might have made changes to the brain. Instead, his team turned to children aged between 3 and 18, none of whom had been diagnosed with a psychiatric condition. Any differences in brain structure among children are more likely to be explained by genes rather than the effects of an established disorder or treatment, says Taquet. Using data already collected from 678 children in the US, the team started by searching for 1877 genetic factors that have been linked to a range of conditions, including schizophrenia, panic disorder, addiction and others. Each child was given a score based on their overall genetic risk for these conditions. His team then assessed scans of the children’s brains. There were “large differences” between the brains of high-risk and low-risk children, says Taquet, and not just in one or two regions of the brain.

9-14-19 Boosting circadian rhythms can help relieve perinatal depression
Women with perinatal depression appear to have altered circadian rhythms. Using light to reset the body clock may improve symptoms. Our bodies run on internal clocks that, in concert with light, wake us up in the morning and leave us sleepy by night time. This circadian rhythm is partly regulated by a suite of genes. These control not only the sleep-wake cycle but also a host of other functions, including metabolism, hormone secretions and body temperature – all of which cycle throughout the day. Something seems to go awry in depression. People with severe depression tend to experience disruptions to their circadian rhythms. Depression can give people daytime sleepiness and night-time insomnia, and research has found higher activity of some circadian genes in people with the condition. Perinatal depression – which occurs during and after pregnancy – seems to be similar. Women tend to get less sleep when they are pregnant, particularly if they have perinatal depression. To find out if circadian genes might play a role, Massimiliano Buoli, Cecilia Maria Esposito and their colleagues at the University of Milan, Italy, looked at seven such genes in 44 women in the third trimester of pregnancy. Thirty of the women had been diagnosed with perinatal depression. By looking at whether epigenetic tags called methyl groups were attached to the genes, the researchers could tell how active these genes were. They found that three circadian genes were more active and one circadian gene was less active in the women who had been diagnosed with depression than those who didn’t have the condition. The team also found that the more methyl groups there were, the more severe a woman’s symptoms were likely to be. This suggests that the greater the difference in circadian gene activity, the more likely a woman is to experience symptoms of depression, say Buoli and Esposito, who presented the findings at the annual meeting of the European College of Neuropsychopharmacology in Copenhagen, Denmark, last week.

9-13-19 Mystery illness: An e-cig reckoning
Amysterious vaping-induced lung illness is proving that “safer than smoking cigarettes” does not mean “safe,” said Amanda Mull in TheAtlantic?.com. Six people have died since August from this lung syndrome, which has severely sickened more than 475 Americans in recent months. Almost all patients have required hospitalization for severe shortness of breath, lung inflammation, fever, dizziness, and vomiting. Now federal health officials are warning people to avoid e-cigarettes, while scientists race to explain why “otherwise healthy” young people are falling ill. Officials say many patients were using bootleg marijuana vaporizers bought off the street, with “vape juice” diluted by vitamin E acetate, a popular skin-care oil that inflames the lungs when heated and inhaled. Some patients also used nicotine vapes, whose health risks are largely unknown despite 14 million U.S. users. Youth vaping is its own health crisis, said Julia Belluz in Vox.com. Teen usage of vapes doubled, to 21 percent, from 2017 to 2018, “the largest increase ever recorded for any substance.” With candy-like flavors such as mango and watermelon, vape giants have marketed to minors, and this week the Food and Drug Administration said Juul unlawfully advertised its products as safer alternatives to cigarettes. In fact, studies have linked vaping to wheezing, and nicotine is known to raise blood pressure, cause arteries to narrow, and even cause seizures in large amounts. The FDA didn’t gain oversight of e-cigarettes until 2016, said USA Today in an editorial, and within that “regulatory vacuum” a “Wild West culture emerged.” The “good news” is that a federal judge recently green-lighted an FDA safety review of e-cigarettes. “In the meantime, vapers beware.”

9-13-19 There is no ‘gay gene’ to predict sexuality
The largest-ever study into the link between sexuality and genetics has found that there is no “gay gene” that determines a person’s sexual orientation. Instead, same-sex attraction appears to be driven by a complex mix of genetic, cultural, and environmental influences—just like many other human traits. “It’s effectively impossible to predict an individual’s sexual behavior from their genome,” co-author Ben Neale, from the Broad Institute of MIT and Harvard, tells CBSNews.com. Homosexuality and bisexuality are a “normal part of variation in our species.” The researchers examined the genetic profiles of nearly 480,000 people in the U.K. and U.S.—about 100 times more than any previous study into genetics and same-sex attraction—who were also asked whether they had ever had a same-sex partner. The scientists identified five specific genetic variants associated with same-sex behavior, including one linked to the biological pathway for smell and others connected to the regulation of sex hormones. Overall, genetics accounts for 8 to 25 percent of same-sex behavior, when thousands of tiny variations across the whole genome are taken into account, researchers concluded. Sexual orientation “is influenced by genes but not determined by genes,” said researcher Brendan Zietsch. But genetic variation does appear to have a stronger influence on same-sex behavior in men than in women, suggesting that female sexuality is more complex.

9-13-19 Going blind from a bad diet
A teenage “fussy eater” who subsisted on junk food went blind and partially deaf because of his terrible diet, according to a new study. The unnamed British teen ate nothing but French fries, Pringles, sausages, processed ham slices, and white bread for the past decade, and first visited a doctor at age 14 complaining of “tiredness,” reports The Washington Post. He was given B12 shots and dietary advice and sent home, but by age 15 was starting to suffer from hearing and vision loss—symptoms that mystified doctors. At 17, he was declared legally blind, and doctors discovered that he still had a B12 deficiency, as well as low levels of copper, selenium, and vitamin D. The teen was diagnosed with nutritional optic neuropathy, a disorder of the optic nerve that in developed nations is caused mostly by chronic alcoholism and medications that interfere with the absorption of nutrients. It is rarely a result of poor diet, because nutritious food is readily available in the West. The case shows the importance of eating “a varied diet,” said study lead author Denize Atan, from Bristol Eye Hospital in England. “There is not a single food that will provide all the vitamins and minerals you need.”

9-13-19 HRT and breast cancer
New research has concluded that the risk of developing breast cancer from hormone replacement therapy is twice as high as previously thought, reports The Daily Telegraph (U.K.). HRT is used by millions of women around the world to relieve the symptoms of menopause, which include hot flashes and night sweats, and scientists have known of the treatment’s link to cancer since the early 2000s. To better gauge that risk, researchers analyzed data from 58 previous HRT studies, which included more than 100,000 postmenopausal women with invasive breast cancer. The metastudy revealed that the general risk of breast cancer for women ages 50 to 69 who have not taken HRT is 6.3 percent. But for women on the most common form of HRT—estrogen and daily progestogen—the risk jumps to 8.3 percent, equivalent to one extra cancer case per 50 users. The risk rises to 6.8 percent for those on estrogen-only therapy, and 7.7 percent for those taking progestogen every two or three days. The risk goes up the longer a woman is on HRT and persists even a decade after treatment stops. “We don’t want to be unduly alarming,” says co-author Richard Peto, from the University of Oxford. “But we don’t want to be unduly reassuring.”

9-13-19 Tattoo needles in lymph nodes
More than ink enters your body when you get a tattoo—metal fragments from tattoo needles that can cause allergic reactions also get left behind. In a new study, researchers examined 12 new steel tattoo needles with a high-powered microscope, both before and after use, reports The New York Times. They found that chromium and nickel particles break off during the tattooing process and become embedded in the skin. Those metals can travel through the body and build up in lymph nodes, potentially triggering an allergic reaction. Interestingly, the needle didn’t fragment when black ink alone was used; the breakdown was caused by titanium dioxide, an abrasive chemical additive used to brighten colored tattoo ink. The research builds on earlier studies that showed pigments can leach from tattoo sites and accumulate in lymph nodes. Anyone thinking of getting a tattoo, says lead author Ines Schreiver, from Germany’s Federal Institute for Risk Protection, should be aware they could be exposed to “impurities that might be allergenic or carcinogenic.”

9-13-19 An island grave site hints at far-flung ties among ancient Americans
Great Lakes and southeastern hunter-gatherers may have had direct contact 4,000 years ago. Ancient North American hunter-gatherers had direct contacts with people living halfway across the continent, researchers say. A ceremonial copper object and related burial practices at a roughly 4,000-year-old human grave site encircled by a massive ring of seashells in what’s now the southeastern United States closely correspond to those previously found at hunter-gatherer sites near the Great Lakes. Because the object and practices appear together, emissaries, traders or perhaps even religious pilgrims must have traveled most or all of the more than 1,500 kilometers from the Upper Midwest to St. Catherines Island, off Georgia’s coast, the researchers conclude September 2 in American Antiquity. Until now, “there was no clear evidence for direct, long-distance exchange among ancient hunter-gatherers in eastern North America,” says anthropologist Matthew Sanger of Binghamton University in New York. Finds at the McQueen shell ring on St. Catherines Island suggest that such exchanges involved objects and ideas that had spiritual significance, such as how to bury the dead. Only a massive, enigmatic earthworks in northern Louisiana called Poverty Point, inhabited from around 3,700 to 3,200 years ago, has yielded copper and other artifacts apparently obtained directly from groups based hundreds of kilometers or more away. But the findings at the McQueen shell ring show for the first time that such exchanges weren’t limited to great gatherings but also occurred between smaller groups going about their daily lives, says Harvard University anthropological archaeologist S. Margaret Spivey-Faulkner, who was not involved in the study.

9-13-19 Research on postmen's testicle warmth wins Ig Nobel
Research measuring if there is a difference in temperature between the left and right testicles is one of the winners of this year's spoof Nobel prizes. Fertility experts Roger Mieusset and Bourras Bengoudifa measured the temperature of French postmen's testicles, both naked and clothed. They found the left one is warmer, but only when a man has his clothes on. The Ig Nobel prizes were announced at a ceremony at Harvard University. In their research "Thermal Asymmetry of the Human Scrotum" published in the journal Human Reproduction, the researchers explained their experiment involved measuring scrotal temperatures with probes every two minutes. They asked 11 postal workers to stand for 90 minutes while they measured the temperature of their scrotums. In another experiment, they measured the temperatures of 11 bus drivers while they were sitting down. The Ig Nobels are spoof prizes that are published in the Annals of Improbable Research but many of the topics recognised in the awards actually have a serious point to them. In this case, other research has suggested the temperature around testicles can affect men's fertility. The quality of men's sperm in the Western world is in decline, but little is known about how to improve it. Craig Franklin told the BBC that he was devastated to find out he had no sperm at all.

9-13-19 We may have a basic form of sign language in common with chimpanzees
We can communicate with chimps. When put to the test, people can usually understand the meaning of ten common gestures used by chimpanzees. Human infants also use some of the same gestures before they can talk, although we don’t yet know if their meanings are the same. The gestures may be the remnants of a basic sign language used by our last common ancestors with apes, says Kirsty Graham, who did the work while at the University of St Andrews in Scotland. “This gestural communication is probably biologically inherited among the great apes – including humans.” One idea about language evolution is that we developed the ability to speak by building on a more primitive kind of sign language. To investigate, the St Andrews team have been recording the meanings of gestures used by gorillas, chimps and bonobos, a related species, to put together the online Great Ape Dictionary. So far they have found about 70 gestures, with about 16 different meanings, as several gestures can convey the same meaning. Most are shared by the three great apes. The researchers set up a website where members of the public could watch short video clips of ten common signs made by chimps and bonobos, and guess what each one meant from four options. By chance they should have got a quarter of the answers right. But people did better than that, picking the correct answer 52 per cent of the time, and this rose to 57 per cent if they were given a brief description of the situation when the gesture was used. Some gestures had success rates over 80 per cent, for instance, when a chimp strokes near its mouth, which means it is asking for food, says Graham, who presented the findings at the European Federation of Primatology meeting in Oxford this week.

9-13-19 Hans Christian Gram: The biologist who helped investigate bacteria
Biologist Hans Christian Gram devised one of the most important staining techniques used in microbiology to identify bacteria under a microscope. Hans Christian Gram, the inventor of the Gram staining technique, was a pioneering biologist who devised the system of classification which led to as many as 30,000 formally named species of bacteria being investigated. He’s the subject of the latest Google doodle, created to honour his birth date of 13 September 1853. Gram, working with German pathologist and microbiologist Carl Friedlander, devised the technique in Berlin in the early 1880s. It is still known as one of the most important staining techniques used in microbiology to identify bacteria under a microscope. Gram first dripped reagents, a substance designed to cause a chemical reaction, onto lung tissue samples. He found differences in the colouring of bacteria that is now known to be Streptococcus pneumoniae and Klebsiella pneumoniae. The differences Gram observed are a result of the composition of the bacterial cell wall. Some bacteria have a cell wall composed of peptidoglycan, a polymer of sugar and amino acids. These “gram-positive” bacterial cells retain the colour of a stain – usually a complex of crystal violet and iodine, or methylene blue – and appear purple or brown under the microscope. Others, that do not contain peptidoglycan, are not stained and are referred to as gram-negative, and appear red. Its popularity peaked between 1940 and 1960. Pierce Gardner, an associate professor of medicine at Harvard Medical School, wrote about the Gram stain and its interpretation in 1974: “It is our feeling that the Gram-stained smear should be considered part of the physical examination of the patient with an acute bacterial infection and belongs in the repertoire of all physicians delivering primary care in acutely ill patients.”

9-13-19 Early whales swam doggy paddle across the ocean from India to Africa
Some early whales may have swum using their arms as well as their legs, a bit like a dog paddling in water. Despite this primitive swimming style, they seem to have managed to spread long distances across the ocean, from India to the western tip of Africa at a minimum. “Even if they are not very good swimmers, they could cross at least one ocean,” says Quentin Vautrin at the University of Montpellier in France. Whales are descended from hoofed land animals similar to modern deer, so the first proto-whales to venture into the water presumably used all four limbs for propulsion, as four-legged animals do today. More modern whales swim by undulating their entire bodies and only use their front limbs – their flippers – for steering. This crucial evolutionary transition took place between 50 and 35 million years ago. We do not fully understand what happened to early whales’ arms during this time because we don’t have many fossils. “We only know the forelimbs for a few species,” says Vautrin. His team has now found a new one. Vautrin and his colleagues unearthed a partial skeleton of an early whale called a protocetid in Senegal. The fossil includes two vertebrae, two ribs, fragments of the feet and tail – and most of an arm. Dated at between 43 and 41 million years old, it sits in the middle of whales’ transition to marine life. “We are far from the earliest whale, but we are a few million years before the real whales,” says Vautrin. Even at this relatively late stage in the evolution of early whales, it seems the animal was using its arms to propel itself. The bones show the protocetid’s arm had powerful muscles and the ability to bend at the elbow. This suggests the animal used it arms — and presumably legs too — to swim, in a way that could have resembled a modern dog. In truth, it is not clear exactly what ‘stroke’ the animal used. The shoulder bones have not been found, so we can’t tell whether the arm could move sideways or just forwards and backwards. “We don’t know if it’s just crawl or more like butterfly,” says Vautrin.

9-12-19 Bones release a hormone that helps us deal with sudden danger
A hormone secreted by bone helps to coordinate our flight-or-fight response, suggesting our skeletons are more active than we thought. When faced with a sudden threat, our heart and breathing rate, blood pressure, circulating blood sugar and body temperature increase to prepare our muscles to fight or run away. This fight-or-flight response is known to be controlled by direct nerve pathways from the brain and hormones released by the adrenal glands. Now, Gerard Karsenty at Columbia University and his colleagues have discovered that a hormone released by bones called osteocalcin also coordinates this response.They found that blood levels of osteocalcin quickly rose in humans when they had to perform a stressful public speaking task. The same thing happened in mice and rats when they were restrained, given electric foot shocks, or exposed to the smell of fox urine. Additional experiments in mice showed that this osteocalcin surge suppressed the body’s “rest-and-digest” functions in order to allow the opposite flight-or-fight mechanisms to proceed. The results build on the group’s previous work showing that bones release osteocalcin to help the muscles burn fuel during exercise, and that osteocalcin injections in older mice make their ageing muscles more youthful. Together, these findings suggest we need a radical re-think of the role of bones, which have previously been viewed as mostly inert structures, says Karsenty. They may have evolved to protect us from acute danger by activating the flight-or-fight response, optimising muscle function, providing the structural framework needed for our bodies to move and escape, and forming a protective cage around our organs, he says.

9-12-19 50 years ago, polio was still circulating in the United States
Excerpt from the September 13, 1969 issue of Science News. Only eight cases of paralytic polio have been reported in the entire United States so far in 1969. But … if infants and young children are not vaccinated as they come along, pockets of the disease could get larger.
Update: The United States saw its last naturally occurring polio case in 1979. Though the paralyzing disease is now close to being eradicated worldwide, it still circulates in Afghanistan and Pakistan, where 66 new cases were recorded this year as of August 22. Meanwhile, dozens of new cases, mainly in Africa, were caused by vaccine strains that reverted to disease-causing versions. Newer vaccine versions yet to be deployed have a lower risk of causing disease, researchers reported in July in the Lancet. Vaccination campaigns are still needed everywhere, or the disease “will come roaring back,” says Oliver Rosenbauer, spokesman for the Global Polio Eradication Initiative. A resurgence could cause “as many as 200,000 new cases” globally a year.

9-11-19 Dean Burnett on why disruptive teens might have saved the human race
The behaviour that defines teenagers might be annoying, but neuroscientist Dean Burnett says it could have been crucial for the survival of our species. My background and origins were quite a hurdle. I’m from a remote, working-class, former mining community in south Wales. I’m also the first person in my family to show any interest in science. Nobody in academia was actively biased against me, but for many people, that world was familiar. I, by contrast, spent a lot of time figuring it out. By the time I did, it was usually too late. I wouldn’t do this even if I could. I’ve just spent months researching how the teenage brain works. Being given weirdly specific, unsolicited instructions from some older bloke who claims he’s you? Given how most teen brains are geared, that’s likely to make them more willing to do the thing you’re warning against. Teenagers are how they are because it was evolutionarily useful. Long term, sticking to the safe and familiar can lead to stagnation and extinction. Having individuals strike out on their own can refresh the gene pool and uncover useful information. Hence, teens reject authority, crave independence, take risks and so on. Far from being a constant annoyance, teenagers may be the reason humanity is as smart and successful as it is.

9-11-19 Netflix's Diagnosis is a real-life House with added crowdsourcing
Netflix's new show Diagnosis is a moving and powerful attempt to help people with unusual medical conditions find new routes to their longed-for diagnosis. WHEN I heard the premises of two new medical shows that use crowdsourcing to help people with undiagnosed conditions, I was extremely sceptical. The medics have failed you, so why not ask some random people what they think the problem is? As it turned out, I was both right and wrong. The first show, Chasing the Cure, uses a live talk show format to highlight several people seeking a diagnosis. Host Ann Curry asks about their symptoms, while messages and texts arrive, offering support or suggesting diseases. A panel of doctors sifts through the contributions, debunking the (mostly) irrelevant. This portion seemed geared towards increasing viewer and online engagement, rather than finding a diagnosis. But the professional hunt for a diagnosis is also performative, with doctors listing potential causes and crossing out ideas. Tests are done off-screen, but they are rarely referred to. At the end, the doctors join Curry and the participants to deliver their verdict. The tone is odd, with a slick studio, game show music and manipulative interviews that mine the emotions of people in real pain. It makes a spectacle of the tough work doctors do when they diagnose rare diseases. I hated every minute. So I’m not sure why I decided to give Netflix’s Diagnosis a try, but I’m glad I did. It is based on a column for The New York Times Magazine by a doctor, Lisa Sanders, about medical mysteries. In it, she opened up cases to anyone with information to share that could help reach a diagnosis.Each episode is centred on one person. Sanders talks them through her process and shares video messages she receives. Most come from informed sources: medical students who recognise the symptoms, vets who have seen such problems in animals and people who have similar diseases.

9-11-19 Vaping deaths: 'A new generation of nicotine addicts'
Doctors in the US are warning people not to use e-cigarettes as they investigate six deaths linked to vaping. But health experts also say there's a long-term addiction crisis because so many American teenagers are already hooked on nicotine.

9-11-19 Am I addicted? The truth behind being hooked on gaming, sex or porn
Urges to play video games, watch pornography or have sex are now spoken of as addictions. Is the science rigorous, or are we just helping people excuse their behaviour? IAN used to play online video games through the night and into the next day. Over eight years, he lost his job, his home and his family. “I would have told you I loved my children more than anything – and I do love my children very dearly – but the truth is I loved the feeling of going online more,” he says. “It made me feel settled, it was a way to cope and it was a physical craving.” For Ian and others like him, video games feel as addictive as a drug. In May, the World Health Organization (WHO) reached a similar conclusion, including gaming disorder in its International Classification of Diseases for the first time. Studies suggest that between 0.3 and 1 per cent of the general population might qualify for a diagnosis. In the UK, plans are under way to open the first National Health Service-funded internet addiction centre, which will initially focus on gaming disorder. But some argue that to pathologise problematic gaming as an addiction is a mistake. In 2017, a group of 24 academics argued against attributing this behaviour to a new disorder. “Of particular concern are moral panics around the harms of video gaming,” they wrote, which have been seen in the fears around games like Fortnite. Such hysteria, the group argued, could lead to premature or incorrect diagnoses.Others simply claim that addiction to gaming, and to other behaviours such as sex, isn’t real, and that suggesting it is trivialises the issue of addiction or lets people off the hook for their actions. It isn’t surprising that this is a complex issue when you consider that even professionals can’t agree on a definition of addiction. “If you speak to 50 psychologists, we’ll all give you a completely different answer,” says Mark Griffiths, director of the International Gaming Research Unit at Nottingham Trent University, UK.

9-11-19 Giant ice age kangaroos had massive cheekbones for crushing bites
Extinct giant kangaroos had skulls built to deliver the powerful crunch needed to eat tough food, such as branches and stems. This may have allowed them to survive long stretches of time when other food was scarce. Extinct giant kangaroos had skulls built to deliver the powerful crunch needed to eat tough food, such as branches and stems. This may have allowed them to survive long stretches of time when other food was scarce. Short-faced kangaroos lived in Australia during the last ice age and are known for their short snouts, large jaws and teeth, and heavily built skulls. D. Rex Mitchell at the University of New England, Australia, created a digital model of the skull of one type of short-faced kangaroo, the 120-kilogram Simosthenurus occidentalis, and analysed the effects of different biting behaviour. He found that the giant kangaroo had teeth so close to the jaw joints that, if its cheek muscles were proportionate to the tree-kangaroo, a living relative, then the chances of its jaw dislocating were high. “But what I noticed was that this species has absurdly huge cheek bones,” says Mitchell. So when he scaled up the size of the cheek muscles to fit the size of the cheekbones, the digital model showed that the risks of the jaw dislocating dropped substantially. Giant pandas have similarly huge cheekbones that support the same large, stabilising muscles. This suggests the kangaroo may have used their premolars to crunch down on tough plant material, much like pandas eat bamboo, says Mitchell. However, it is also possible that the kangaroos held tough branches in their teeth and pulled them down to break them. The digital model suggests the giant kangaroo could have eaten tougher plants than any currently living Australian herbivores can, says Mitchell. S. occidentalis is thought to have survived until around 42,000 years ago, meaning it possibly lived alongside humans for around 20,000 years.

9-11-19 Artists who paint with their feet have ‘toe maps’ in their brains
Scans of the organ reveal areas that sense individual touches. Two artists who paint with their toes have unusual neural footprints in their brains. Individual toes each take over discrete territory, creating a well-organized “toe map,” researchers report September 10 in Cell Reports. Similar brain organization isn’t thought to exist in people with typical toe dexterity. So finding these specialized maps brings scientists closer to understanding how the human brain senses the body, even when body designs differ (SN: 6/12/19). “Sometimes, having the unusual case — even the very rare one — might give you important insight into how things work,” says neuroscientist Denis Schluppeck of the University of Nottingham in England, who was not involved in the study. The skills of the two artists included in the study are certainly rare. Both were born without arms due to the drug thalidomide, formerly used to treat morning sickness in pregnant women. As a result, both men rely heavily on their feet, which possess the dexterity to eat with cutlery, write and use computers. The brain carries a map of areas that handle sensations from different body parts; sensitive fingers and lips, for example, have big corresponding areas. But so far, scientists haven’t had much luck in pinpointing areas of the human brain that respond to individual toes (although toe regions have been found in the brains of nonhuman primates). But because these men use their feet in unusually skilled ways, researchers wondered if their brains might represent toes a bit differently. The two artists, along with nine other people with no special foot abilities, underwent functional MRI scans while an experimenter gently touched each toe. For many people, the brain areas that correspond to individual toes aren’t discrete, says neuroscientist Daan Wesselink of University College London. But in the foot artists’ brains, “we found very distinct locations for each of their toes.” When each toe was touched, a patch of brain became active, linking neighboring toes to similarly neighboring areas of the brain.

9-11-19 ‘The Nature of Life and Death’ spotlights pollen’s role in solving crimes
A botantist explains the science of forensic ecology. Even if a criminal doesn’t leave behind fingerprints or DNA, detectives need not worry. Crime scenes are peppered with other clues — pollen and spores — that can trip up even the most careful crooks. These clues are central to forensic ecology, in which scientists analyze biological material to help detectives solve crimes. In The Nature of Life and Death, botanist Patricia Wiltshire lays out the science underlying the discipline — which she helped pioneer in the United Kingdom — as she chronicles some of her most memorable cases of the last 20 or so years. Early in her career, Wiltshire used the power of pollen and spores to analyze archaeological sites. The qualities that make these particles useful for studying the past also make them useful for solving crimes. The particles’ natural polymers can be long-lasting, and in certain conditions, pollen and spores persist longer than other forms of evidence, even for thousands of years. More important for detectives, these biological bits are often as distinctive as the plants and fungi that make them, providing telltale clues of where a crime has happened or where a criminal has been. In part because of their minuscule size, pollen and spores are particularly susceptible to static electricity, doggedly clinging to the clothing and hair of victims and perpetrators alike. Criminals often don’t even realize they’re covered in the tiny particles. The combination of pollen and spores at a site can be as distinct as a fingerprint, especially when dealing with rare plants or fungi, or pollen that isn’t spread far and wide by the wind, Wiltshire explains. By studying the material, she has, for example, determined where and during which season crimes have occurred. In one murder case, Wiltshire used pollen and spores from a gardening tool, the tennis shoes of the murderer and the foot pedals of the victim’s car to identify the woodland locale in northern England where the victim’s body had been dumped.

9-10-19 HPV vaccinations seem to be creating herd immunity for US men
Oral HPV infection rates are now 37 per cent lower among unvaccinated US men, suggesting the widespread rollout of the HPV vaccine has led to herd immunity. In the US, vaccinations to protect against the most common types of HPV were first officially recommended for girls in 2006 and for boys in 2011. In addition to causing most cervical cancer, HPV is also linked to some types of mouth and throat cancers. Despite this, little research has been done on the effects of the vaccine on oral cancers, so Anil Chaturvedi at the National Cancer Institute in the US and his colleagues looked at a nationwide survey on HPV infections in the years following the vaccines’ introduction. Almost 14,000 adults took part in the survey, conducted from between 2009 and 2016. Over those years, HPV vaccination rates increased from zero to 5.8 per cent in men and from 7.3 per cent to 15.1 per cent in women. During this period, the prevalence of the types of HPV included in the vaccines dropped from 2.7 per cent to 1.6 per cent in men who had not been vaccinated. This represented a 37 per cent drop among the unvaccinated adult men. This suggested herd immunity was protecting these men, the team wrote. “Herd protection likely arises from increased levels of female HPV vaccination in the US population.” Chaturvedi and his colleagues failed to find a similar protective effect among unvaccinated women in their study. This could be explained by a low prevalence of oral HPV in the women included, they wrote. There are more than 100 different types of HPV, and the current vaccines only protect against the most common and harmful types. The number of men infected with HPV types that were not included in the vaccine remained the same over the study period.

9-10-19 Earliest direct evidence of milk consumption
Scientists have discovered the earliest direct evidence of milk consumption by humans. The team identified milk protein entombed in calcified dental plaque (calculus) on the teeth of prehistoric farmers from Britain. It shows that humans were consuming dairy products as early as 6,000 years ago - despite being lactose intolerant. This could suggest they processed the raw milk into cheese, yoghurt or some other fermented product. This would have reduced its lactose content, making it more palatable. The team members scraped samples of plaque off the teeth, separated the different components within it and analysed them using mass spectrometry. They detected a milk protein called beta-lactoglobulin (BLG) in the tartar of seven individuals spanning early to middle Neolithic times. "Proteomic analysis of calculus is a fairly recent technique. There have been a few studies before, but they have generally been on historical archaeological material rather than prehistoric material," co-author Dr Sophy Charlton, from the department of archaeology at the University of York, told BBC News. Lactose intolerance arises from the inability to digest the lactose sugar contained in milk beyond infancy. This means that consuming milk-based foods can cause uncomfortable symptoms such as abdominal pain, diarrhoea and nausea. However, many modern Europeans possess a genetic mutation which allows for the continued consumption of milk into adulthood. This mutation affects a section of DNA controlling the activity of the gene for lactase - an enzyme that breaks down lactose sugar. However, previous studies of the genetics of Neolithic Europeans show that they lacked this mutation. Dr Charlton said it was possible these Stone Age people were limiting themselves to small amounts of milk. "If you are lactose intolerant and you consume very, very small amounts of milk, then it doesn't make you too ill. You can just about cope with that," she explained. But Dr Charlton added: "The alternative option, which I think is perhaps slightly more plausible, is that they were processing the milk in such a way that it's removing a degree of the lactose. So if you process it into a cheese, or a fermented milk product, or a yoghurt, then it does decrease the lactose content so you could more easily digest it. "That idea fits quite well with other archaeological evidence for the period in which we find dairy fats inside lots of Neolithic pottery, both in the UK and the rest of Europe."

9-10-19 Supercooling tripled the shelf life of donor livers
Chemicals that prevent the human tissue from freezing may help ease organ shortages. A new technique to keep donor organs colder than ice cold could greatly extend the length of time that those organs are viable for transplant. Typically, donor organs stay viable for several hours on ice at about 4° Celsius. Tissue can last even longer at lower temperatures — but below zero degrees Celsius, the formation of ice crystals risks damaging an organ and rendering it unusable. Now, using chemicals that prevent an organ from freezing at subzero temperatures, researchers have preserved five human livers at –4° C. That supercool storage system tripled the livers’ typical shelf life from nine to 27 hours, researchers report online September 9 in Nature Biotechnology. This kind of deep-chill technology “would be huge for transplantation,” says Jedediah Lewis, president and CEO of the Organ Preservation Alliance in Berkeley, Calif., a nonprofit that supports research on organ and tissue preservation but was not involved in this research. Every year, thousands of donor organs are discarded for various reasons, including the inability to find a suitable patient close enough to receive the organ before it goes bad. If donor tissue were viable longer, doctors could get organs to patients who might otherwise be too far away, Lewis says. That could lead to more lifesaving surgeries for patients waiting for a transplant — currently more than 100,000 in the United States alone. Pushing back organs’ expiration dates could also curb the costs of private flights to rush organs between cities and allow for more flexible surgery scheduling, Lewis adds.

9-10-19 A new prosthetic leg that senses touch reduces phantom pain
Agility and confidence while walking increased in two men who tested the device. A prosthetic leg that can feel helped two men walk faster, more smoothly and with greater confidence. The artificial leg, outfitted with sensors that detect pressure and motion, also curbed phantom pain that came from the men’s missing legs, researchers report online September 9 in Nature Medicine. Restoring these missing signals may greatly improve the lives of people who rely on prosthetic limbs (SN: 1/28/11). Neuroengineer Stanisa Raspopovic of EHT Zürich and colleagues tested the device in two men, both of whom had a leg amputated above the knee. Their new prosthetic legs were outfitted with seven sensors that detect foot pressure on the ground and one sensor that decodes the angles of the knee joint. Electrodes implanted on the sciatic nerve, just above the amputation site, then stimulated the nerve with signals from the sensors on the prosthesis. “If you close your eyes, you will think that you have your own leg,” volunteer Savo Panic said in Serbian in a translated video released by the researchers. When those sensory signals were present, the two men walked faster and more confidently, even over difficult sandy terrain. What’s more, unpleasant feelings of pain from their missing leg lessened. After about a month of use, one of the men reported no pain at all, and the other man said his pain was sporadic.

9-10-19 Culture helps shape when babies learn to walk
Motor development models based on Western standards are too narrow. For generations, farther back than anyone can remember, the women in Rano Dodojonova’s family have placed their babies in “gahvoras,” cradles that are part diaper, part restraining device. Dodojonova, a research assistant who lives in Tajikistan, was cradled for the first two or three years of her life. She cradled her three children in the same way. Ubiquitous throughout Central Asia, the wooden gahvora is often a gift for newlyweds. The mother positions her baby on his back with his bottom firmly over a hole. Underneath is a bucket to capture whatever comes out. She then binds the baby with several long swaths of fabric so that only the baby’s head can move. Next, she connects a funnel, specially designed for either boys or girls, to send urine out to that same bucket under the cradle. Finally, she drapes heavy fabric over the handle atop the gahvora to protect the child from bright light and insects. Babies stay in that womblike apparatus for hours on end, with use decreasing as the child ages. When babies fuss, mothers often shush them by vigorously rocking the cradle back and forth or leaning over the side to breastfeed. Besides keeping babies dry and warm, gahvoras provide a sense of safety, Dodojonova says. “It is very nice for children because they are bound and cannot move.” Eventually, they are running and jumping like children everywhere. To the uninitiated, this child-rearing approach may sound odd, or even shocking. Yet cultures should be viewed within their own context, says psychologist Catherine Tamis-LeMonda of New York University. “We engage in practices that fit our needs, our own everyday lives.”

9-10-19 The day the dinosaurs' world fell apart
Scientists have a recording of the worst day on Earth; certainly the worst day in the last 66 million years. It takes the form of a 130m section of rock drilled from under the Gulf of Mexico. These are sediments that were laid down in the seconds to hours after a huge asteroid had slammed into the planet. You'll know the event we're talking about - the one researchers now think was responsible for the demise of the dinosaurs and the rise of mammals. The high-resolution account of this catastrophe was recovered by a UK/US-led team, who spent several weeks in 2016 drilling into what remains of the crater produced by the impact. Today, this 200km-wide structure is positioned under Mexico's Yucatan Peninsula, with its best preserved central portions sitting just offshore of the port of Chicxulub. The team pulled up a great long core of rock but it's a particular 130m-long section that essentially documents the first day of what geologists call the Cenozoic Era, or as some others like to refer to it: the Age of Mammals. 1. A 12km-wide object dug a hole in Earth's crust 100km across and 30km deep. 2. This bowl then collapsed, leaving a crater 200km across and a few km deep. 3. The crater's centre rebounded and collapsed again, producing an inner ring. 4. Today, much of the crater is buried offshore, under 600m of sediments. 5. On land, it is covered by limestone, but its rim is traced by an arc of sinkholes. The section is a nightmarish jumble of shattered material, but its contents are arranged in such a way that scientists say they can discern a clear narrative. The bottom 20m or so, is dominated by glassy debris. This is the rock that was melted by the heat and pressure of the impact. It lapped across the base of the crater in the subsequent seconds and minutes. This then transitions to a lot of fragmented melt rock - the result of explosions as water rushed across the hot material. The water came from the shallow sea covering the area at the time. It would have been pushed temporarily out of the way by the impact but when it came back in and made contact with the broiling rock, it would have set off violent reactions. Something similar occurs at volcanoes where magma interacts with seawater. This phase covers the first minutes to an hour. But the water keeps coming, filling up the crater, and the top 80-90m of the core section is built from all the debris that was in this water and ultimately rained out. Larger fragments initially followed by finer and finer material. The timescale for this is the first hours after the impact. And then, right at the top of the 130m core section is evidence of a tsunami. The sediments all dip in one direction and their organisation suggests they were deposited in a high-energy event. Scientists say the impact would have generated a giant wave pulse that would have crashed on to shorelines hundreds of kilometres from the crater. But this outward train would also have had a return pulse and it's the debris carried in this tsunami that caps the top of the rock sequence. "This is all still Day One," says Prof Sean Gulick from the University of Texas at Austin. "Tsunamis move at the speed of a jet plane. Twenty-four hours is a generous amount of time for the waves to move out and come back in again," he told BBC News.

9-9-19 Transplant organs can be supercooled to below zero for longer storage
The length of time that a liver can be kept outside the body has been extended to a day and a half by a new “supercooling” method, which for the first time has let human organs be safely stored at sub-zero temperatures. The technique, which lowers the organ’s temperature below zero without forming damaging ice crystals, could boost the number of liver transplants carried out and could also be used on other organs, says Reinier de Vries of Harvard Medical School in Boston. There is a shortage of organs available for transplant, with about 14,000 people on the liver waiting list in the US, for example. A big problem is that when an organ becomes available from someone who has died, it can only be stored outside the body, at 4 degrees C, for a short time – up to 12 hours in the case of livers – which limits how far it can be transported. “It’s a race against the clock,” says de Vries. His team has developed a method for cooling livers down to -4 degrees C without them freezing. The organ is connected to a machine that perfuses it with chemicals to lower the freezing point, and air is removed from the storage bag, to avoid ice crystals forming at air-liquid contact points. The method was tested on three human livers that had been made available for transplant but weren’t in good enough condition to use. After the sub-zero storage and rewarming, all three organs seemed to recover well when they were perfused with blood at body temperature, as they started making bile. As the organs are not frozen they cannot be kept below zero indefinitely, but de Vries says they will now try extending the storage period past a day and a half. It could also be used with hearts and kidneys, although lungs would be more difficult because they are filled with air. “The larger the volume of the organ, the more difficult it becomes. Human livers are the largest solid organ.”

9-9-19 An artificial leg with sensors helps people feel every step
An artificial leg has sensors to let people feel when it flexes and lands on the ground – which helps them to walk more quickly and confidently. The first two people to use the new kind of prosthetic legs found they also had less phantom limb pain, the mysterious phenomenon when amputees get rogue sensations that seem to come from their missing limb. Many people with an artificial leg find it hard to use, especially those who have lost their leg above the knee. Part of the problem is that it feeds back no sensations, making it hard to judge its position and motion. Stanisa Raspopovic of the Swiss Federal Institute of Technology in Zürich, Switzerland, and colleagues took a commercially available artificial leg and put sensors on the sole of the foot and inside the knee that could be connected by wires to nerves in the person’s thigh.The team gave two men the chance to test out their legs, by connecting up their nerves to the wires. For the first month they tested the best way to stimulate their nerves to generate the most realistic sensations. “They described it as close to lifelike,” says Raspopovic. Then the men tested out the legs on an outdoor track. Both walked faster with the new limbs than when the feedback was turned off, by up to 6 meters per minute and they felt more confident in the limb. “Being able to perceive the motion of your joints is incredibly important,” says Aadeel Akhtar of the University of Illinois at Urbana-Champaign, who was not involved in the work. “It makes you feel like the prosthetic becomes your own.” Over three months, one man’s phantom limb pain went completely and the other’s fell by 80 per cent. “I would argue that’s an even bigger benefit,” says Akhtar.

9-9-19 Ancient footprints show Neanderthals may have been taller than thought
We know Neanderthals mated with us, painted on cave walls and may have used herbal medications. Now an analysis of the biggest tranche of Neanderthal footprints yet discovered offers a window into their lives. The 257 fossil footprints were found in a coastal creek bed in Le Rozel in northern France. They were made around 80,000 years ago and preserved in sandy mud. Most of the footprints were from children and may show that Neanderthals could have been taller than previously thought. “The discovery of so many Neanderthal footprints at one site is extraordinary,” says Isabelle de Groote at Liverpool John Moores University, who was not involved with the study. Before this, only nine Neanderthal footprints were known, from 4 different sites, says Jérémy Duveau of the Muséum National d’Histoire Naturelle in France, who led the team that carried out the analysis. “Footprints are very interesting because they give a snapshot of a moment of life of hominins such as Neanderthals, and allow us to estimate the size and composition of the group that made them.” This kind of information is hard to obtain from other archaeological artefacts such as skeletons and tools. Although the researchers can’t be certain that the 80,000-year old footprints at Le Rozel were made by Neanderthals, as no hominin skeletal remains were found at the site, Neanderthals were the only known hominins in Europe at that time – Homo sapiens arrived some 35,000 years later. The footprints of Neanderthals are wider than those of modern humans because their feet were broader. From the size of the Le Rozel footprints, the researchers could estimate the size of the individual who made them, and then infer their age.

9-9-19 Defeat malaria in a generation - here's how
The world could be free of malaria - one of the oldest and deadliest diseases to affect humanity - within a generation, a major report says. Each year there are still more than 200 million cases of the disease, which mostly kills young children. The report says eradicating malaria is no longer a distant dream, but wiping out the parasite will probably need an extra $2bn (£1.6bn) of annual funding. Experts say eradication is a "goal of epic proportions". Malaria is a disease caused by Plasmodium parasites. These are spread from person to person by the bite of female mosquitoes in search of a blood meal. Once infected, people become very sick with a severe fever and shaking chills. The parasites infect cells in the liver and red blood cells, and other symptoms include anaemia. Eventually the disease takes a toll on the whole body, including the brain, and can be fatal. Around 435,000 people - mostly children - die from malaria each year. The world has already made huge progress against malaria. Since 2000: 1. The number of countries with malaria has fallen from 106 to 86. 2. Cases have fallen by 36%. 3. The death rate has fallen by 60%. This is largely down to widespread access to ways of preventing mosquito bites, such as bed nets treated with insecticide, and better drugs for treating people who are infected. "Despite unprecedented progress, malaria continues to strip communities around the world of promise and economic potential," said Dr Winnie Mpanju-Shumbusho, one of the report authors. "This is particularly true in Africa, where just five countries account for nearly half of the global burden." Eradicating malaria - effectively wiping it off the face of the planet - would be a monumental achievement. The report was commissioned by the World Health Organization three years ago to assess how feasible it would be, and how much it would cost. Forty-one of the world's leading malaria experts - ranging from scientists to economists - have concluded that it can be done by 2050. Their report, published in the Lancet, is being described as "the first of its kind".

9-9-19 Europeans have steadily accumulated mutations for thousands of years
The number of mildly harmful mutations in the European population has gradually increased over the last 45,000 years, ever since modern humans arrived on the continent. The mutations may be a lingering effect of the original migration into Europe. “These mutations that today are associated with genetic disease do not decrease over time,” says Stéphane Aris-Brosou of the University of Ottawa in Canada. However, while many of the mutations are linked to diseases, their effects are minor and it is unlikely that they are causing the people who have them significant harm. Our species evolved in Africa and only moved into Europe in a big way 45,000 years ago. Geneticists have known for decades that African populations contain much more genetic diversity than non-African groups. This is because the first groups that moved out of Africa were fairly small. To find out how European genomes have been affected by this, Aris-Brosou examined the genomes of 2062 Europeans, including 1179 ancient genomes dating back to up to 45,000 years. For each genome, he looked at 1.2 million sites where a single “letter” on the DNA varies from person to person. Many of these genetic variants have previously been found to be statistically associated with diseases like asthma and diabetes, although their effects are often small: having a single harmful variant would only slightly increase a person’s chances of developing diabetes. Aris-Brosou found that the number of mildly harmful variants in the European population has steadily increased over time. The key factor was probably the small initial populations in places like Europe, which allowed the harmful mutations to become common. “Then it’s very hard to get rid of them,” says Laura Botigué of the Centre for Research in Agricultural Genomics in Barcelona, Spain.

9-8-19 How you live affects your sperm - and perhaps your future children too
Would-be dads take note. Lifestyle choices from smoking to exercise to wearing tight underpants lead to subtle changes in your sperm that may affect the health and behaviour of your children. “What a man does throughout his life has an impact on his sperm,” says Kenneth Aston at the University of Utah. “Those changes may confer risk to offspring.” The focus is usually on mothers when it comes to smoking, but a father’s behaviour also affects his children’s health. One way this can happen is by pregnant women and children being exposed to fathers’ cigarette smoke. However, there is growing evidence that even smoking before conception increases children’s risk of developing a wide range of diseases, from autism to cancers. In part this is because the sperm (and eggs) of smokers have more mutations in their DNA. In 2017, Aston’s team showed that there are also epigenetic changes in the sperm of men who smoke. Epigenetic changes, such as the addition of methyl groups to DNA, don’t change the underlying DNA sequence but can alter the activity of genes. Aston found widespread changes in DNA methylation in the sperm of smokers. What wasn’t clear was whether these changes affect children. In theory, all the methylation changes might be wiped away in developing embryos. So Aston’s team has now exposed male mice to cigarette smoke. The offspring of these mice had altered methylation patterns and altered gene expression in the prefrontal cortex of the brain compared with mice whose fathers were not exposed to smoke. That strongly suggests that the epigenetic changes in sperm due to lifestyle factors such as smoking do indeed affect the health and behaviour of children, the team concludes. Men need to be aware of this, Aston says. “I don’t think many men think about the impacts that their behaviour prior to conception has on their offspring. That’s something I didn’t think about when I was having kids.”

9-7-19 Vaping is suspected in a fifth death and hundreds of injuries
It’s unclear what e-cigarette device or product may be driving the growing number of cases. U.S. health officials have now reported five deaths from severe lung illnesses tied to vaping, with 450 possible cases of these lung injuries reported in 33 states and one U.S. territory. That’s more than double the 215 cases reported a week ago. It’s unclear whether a particular substance vaped or a type of vaping device is behind the illnesses, federal and state health authorities announced September 6 in a news conference. “So far, no definitive causes have been established,” said Dana Meaney-Delman of the lung injury response group at the Centers for Disease Control and Prevention in Atlanta. For now, federal health officials are urging people not to use e-cigarettes, and say that vaping is especially harmful to youth, young adults and pregnant women. The New York State Department of Health is eyeing one possible suspect substance, saying on September 5 that high levels of vitamin E acetate had been found in some vape products containing cannabis. Vitamin E acetate is a dietary supplement and ingredient in some skin care products, but could be toxic when inhaled. But it is still too early to focus on any one substance, federal officials cautioned in the news conference. The Food and Drug Administration is testing more than 120 samples from vaping products for a broad range of chemicals, including nicotine and tetrahydrocannabinol — the psychoactive ingredient in marijuana known as THC — as well as various diluents and additives and even pesticides and opioids. “The samples we’re continuing to evaluate show a mix of results, and no one substance or compound, including vitamin E acetate, has been identified in all of the samples tested,” said Mitch Zeller, director of the FDA’s Center for Tobacco Products in Silver Spring, Md.

9-7-19 The longest Dead Sea Scroll sports a salt finish that the others lack
The treatment may help explain why the Temple Scroll is remarkably bright. Decades after the Dead Sea Scrolls were discovered in desert caves, the ancient manuscripts are still offering surprises. Chemical analysis of the Temple Scroll, the longest of the scrolls, has revealed a salty coating on the text side of the scroll that hasn’t been previously found on the others. This unusual finish suggests that the Temple Scroll’s remarkably bright parchment was manufactured differently from other documents in the collection, researchers report online September 6 in Science Advances. It’s not yet clear how the mineral coating may have contributed to the Temple Scroll’s striking appearance, says Admir Masic, a materials scientist at MIT. But understanding the properties of this manuscript and others like it could inform strategies for preserving these 2,000-year-old documents, which include sections of the Hebrew Bible, as well as help in spotting forgeries. Masic and colleagues scrutinized a small fragment of the Temple Scroll using X-ray and Raman spectroscopy. These techniques involve shining radiation on a sample and measuring the light that emanates back out to map the material’s chemical composition. “This surprise came out, of salts that we weren’t expecting to find at all,” Masic says. The mixture atop the Temple Scroll mostly comprises sulfate salts, including minerals like gypsum, glauberite and thenardite, not previously seen on the Dead Sea Scrolls (SN: 11/17/17). “Sometimes you find a lot of inorganic components on these scrolls or fragments, and they probably came from the caves,” Masic says. But since the minerals on the Temple Scroll aren’t generally found in the region around the Dead Sea, it’s more likely that these materials were used in the scroll’s production, the researchers conclude.

9-6-19 Two people have died from lung disease after vaping – what’s going on?
Two deaths in the US have now been attributed to vaping-related lung conditions, and state governments are taking actions to crack down on the types of e-cigarettes available. Here’s what you need to know about this mysterious illness and the response to the outbreak. In July, an Illinois resident developed a lung infection and died after using a vaping device that contained marijuana oil. Yesterday, officials in Oregon said that a resident of the state who used e-cigarettes had also died after being hospitalised for a severe lung infection. It’s not clear why these respiratory problems led to the people’s deaths. It could be that something either in the e-cigarette or the substances smoked through them caused serious inflammation of the lungs. The US Centers for Disease Control and Prevention (CDC) says that as of 27 August, 215 possible cases of vaping-related severe lung disease have been reported by 25 states. In addition to the deaths in Illinois and Oregon, this multistate outbreak includes people who have reported coughs, shortness of breath, chest pain, fever, fatigue, nausea, vomiting and diarrhoea. These symptoms developed over days or weeks. Some people turn up to hospital with symptoms that look like pneumonia, and have been put on ventilators or treated in intensive care units. We’re not certain, but there could be a connection. In every one of these cases, people reported using e-cigarettes. But no single e-cigarette product or substance has been associated with all the illnesses. The CDC says that recent inhalation of cannabis products and THC, the main psychoactive compound in marijuana, has been reported in many patients from two states.

9-6-19 Why do fragrances cause health problems for one in three people?
One in three adults say that fragranced products cause them health problems, and one in ten say the effects are so bad that they have missed work or lost jobs, suggests a survey of over 4000 people. But it is unclear whether the symptoms people experience are direct physiological responses, or whether they have a psychological component. Fragrances are used to mask smells or add a nice aroma in to a wide range of products, including in many cosmetics, cleaning supplies, air fresheners, laundry detergents and soaps. Previous surveys have found that people believe they experience a range of health issues when exposed to such fragrances. An increasing number of people are describing themselves as having “chemical sensitivity”, in which low levels of chemicals in their everyday environment trigger a diverse range of symptoms. But little is known about what may be causing these problems. To get a better understanding of how common fragrance sensitivity is and how it affects daily life, Anne Steinemann at the University of Melbourne, Australia, surveyed around 1100 nationally representative individuals each from the US, Australia, the UK and Sweden. These were randomly recruited from a research survey database of over six million people. One in three respondents said fragranced products affected their health. The highest rate of issues was in the US, where nearly 35 per cent reported problems with fragrances. The lowest reported incidence was in the UK, where nearly 28 per cent of respondents said they were adversely affected by fragrances. One in five respondents said their health had been affected by being near someone wearing a fragranced product, while one in six said they experienced health problems around air fresheners or in rooms cleaned with fragranced products.

9-6-19 DNA indicates how ancient migrations shaped South Asian languages and farming
An analysis of more than 500 skeletons reveals the genetic and cultural ancestry of the region. A new DNA study of unprecedented size has unveiled ancient human movements that shaped the genetic makeup of present-day South Asians in complex ways. Those long-ago treks across vast grasslands and through mountain valleys may even have determined the types of languages still spoken in a region that includes what’s now India and Pakistan. The investigation addresses two controversial issues. First, who brought farming to South Asia? Genetic comparisons indicate that farming was either invented locally by South Asian hunter-gatherers or launched via borrowing of knowledge from other cultures, rather than brought by Near Eastern farmers from what’s now Turkey. No DNA signs were found of those farmers, who earlier studies suggested had brought farming to Europe. Second, where did local languages originate? New DNA evidence supports the idea that mobile herders from Eurasian steppe grasslands, not Near Eastern farmers, brought Indo-European languages to South Asia. Ancient DNA had already suggested that Indo-European speaking Eurasian herders called the Yamnaya reached parts of early Bronze Age Europe by around 5,000 years ago (SN: 11/15/17). Yamnaya-related ancestry appeared among South Asians between around 3,900 and 3,500 years ago, an international team reports in the Sept. 6 Science. “By the early Bronze Age, human movements were stirring the genetic pot throughout Asia,” says archaeologist Michael Frachetti of Washington University in St. Louis. He led the massive project along with Harvard Medical School geneticists David Reich and Vagheesh Narasimhan and archaeologist Ron Pinhasi of the University of Vienna.

9-6-19 Jurassic turtle may have been crushed underfoot by a giant dinosaur
It brings a whole new meaning to the word shellshock. A Jurassic turtle seems to have been squashed flat before it was fossilised – possibly because a giant dinosaur trod on it. The marine turtle fossil was found in 2007 in Switzerland, as part of a project to study fossils that had been revealed by the construction of a highway. It dates from about 155 million years ago in the late Jurassic period. The dinosaurs were at their height then, and huge, long-necked sauropod dinosaurs dominated the land. Most turtles from the time are found in marine sediments, but this one was on land. “It’s like a tidal flat, where we mostly found dinosaur prints and tracks,” says palaeontologist Christian Pu¨ntener, who was employed by the Republic and Canton of Jura in Switzerland to study the fossils. Finding the turtle there is significant, he says, because previously there was no hard evidence that Jurassic marine turtles ventured onto land. The turtle was on its back, which suggests it had become stuck on the tidal flat and died there, says Pu¨ntener. It’s not clear what it was doing there. One possibility is that it came ashore to lay eggs, as marine turtles do today, but it is unclear if the animal was male and female, and if the tidal flat was a nursery there ought to be more turtle fossils. However, the most striking thing about the turtle is the state of the fossil. Most of it is unusually flat. Seen from the side, a big chunk of it is visibly lower than the rest in the rocks. “The main shell part is pushed down, relative to the posterior part,” says Pu¨ntener. This suggests a heavy weight crushed much of the shell.

9-5-19 Drug cocktail seems to reverse biological signs of ageing in people
Is this the world’s first anti-ageing drug? Scientists have made people younger for the first time, or so they think. Nine men took a year-long drug regime that appeared to reverse the ageing process, leaving them one-and-a-half years younger – biologically – than when they started. The clinical trial was the first to investigate the possibility that a drug might be able to reverse the biological signs of ageing, increasing lifespan. However, the results are limited by the fact that this was a feasibility study without a placebo. The men, aged 51 to 65, took a drug cocktail involving recombinant human growth hormone (rhGH), three to four times a week for a year. At the beginning and end of the trial they had their biological age measured. We all have a chronological age – the number of candles on our birthday cake – and an epigenetic, or biological age, which is a measure of how quickly the cells in our body are deteriorating compared with the general population. These two figures can differ, and our epigenetic age is often a better predictor of lifespan. The researchers used four different tests of epigenetic age. On average, across the four tests, the volunteers’ epigenetic age was 1.5 years younger than it was at the beginning of the treatment. This means someone who had an epigenetic age of 55, say, at the beginning of the trial had an epigenetic age of 53.5 at the end of the year-long trial. The most advanced test, “GrimAge” – named after the Grim Reaper – showed a 2-year decrease in epigenetic versus chronological age that persisted six months after the men stopped taking the drug therapy.

9-5-19 Tyrannosaurus rex had 'air-con' in its head
As a big, active predator, the mighty Tyrannosaurus rex needed a way to cool down. Now, scientists say that two large holes in its skull acted as a kind of internal "air-conditioning unit", to help the dinosaur lose heat. These anatomical features on the top of the head were previously thought to have been filled by muscles. But a team says it's more likely this area was filled with blood vessels that helped T. rex regulate its temperature. Large animals need special ways to cool down, since their immense body heat can overwhelm them in hot conditions. Casey Holliday, from the University of Missouri, and colleagues, used thermal imaging devices - which translate heat into visible light - to examine alligators at the St Augustine Alligator Farm Zoological Park in Florida. "It's really hard to get a picture of an alligator skull in the wild, because they're always off away from you and they're dangerous to approach," he said. "Being at the farm allowed us to get up and over fences and take images and video from the top down." They discovered that the alligators have blood-vessel-filled holes in their skulls. "An alligator's body heat depends on its environment," said co-author Kent Vliet, from the University of Florida in Gainesville. "We noticed when it was cooler and the alligators are trying to warm up, our thermal imaging showed big hot spots in these holes in the roof of their skull, indicating a rise in temperature. Yet, later in the day when it's warmer, the holes appear dark, like they were turned off to keep cool." By examining fossils and 3-D images of Tyrannosaurus rex's skull, the scientists discovered that the dinosaur had similar holes. In the past, scientists believed the two large features in the roof of the extinct predator's skull - called the dorsotemporal fenestra - were filled with muscles that assist with jaw movements.

9-4-19 The psychobiotics revolution has implications for us all
The discovery that gut bacteria can boost our mood may herald a new way of treating mental health conditions. “KILLS all known germs” was once an effective advertising slogan. Now we know this promise isn’t as desirable as it might sound. Not all “germs” are bad. In fact, you couldn’t survive without help from the many microbes that live on and within you. A thriving microbiome isn’t just essential for your physical health, though. In the latest twist to this story it turns out that microbes in your gut also influence your mood. These so-called psychobiotics are intimately entwined with us from birth. They help shape the developing human brain, particularly the areas associated with emotions. They also exert day-to-day control over how we feel. The mystery of how single-celled organisms have an effect on our minds from a distance is starting to be solved (see “How what you eat directly influences your mental health”). Intriguingly, bacteria in our intestinal tract can produce almost all the same neurotransmitters we generate in our brains, and they have a hotline from the gut to the head. As yet, we don’t know exactly which microbes influence our moods. Still, we know enough about psychobiotics to start to benefit from them. Experiments show that consuming certain probiotic foods can help people cope with anxiety and depression, the most common causes of disability worldwide. With more research and a better understanding of the bacteria involved, psychobiotics look set to offer a real alternative to drugs and cognitive behavioural therapy for a range of mood disorders. Some will find this liberating, because it offers hope of taking back control from a mental health condition. But the psychobiotics revolution has implications for all. Anyone can cultivate feel-good bacteria in their gut with the right kind of diet (see “Healthy gut, happy mind: What to eat to boost how you feel”). You really can eat yourself happier.

9-4-19 The world is getting better, so why are we convinced otherwise?
We need a better handle on our ignorance if we want to improve our lives, says Ola Rosling, a proponent of factfulness - holding only opinions supported by strong facts. OLA ROSLING isn’t afraid to point out your mistakes. He is the president of Gapminder, the foundation he set up with his wife Anna Rosling Rönnlund and his late father Hans Rosling. Gapminder is dedicated to exposing common misconceptions about the world and promoting a fact-based viewpoint. The foundation uses data visualisations and quizzes to reveal how little we really know, asking people things like whether they believe the world is getting better or worse, and what they think is the average life expectancy for people globally. He also advocates a “factfulness” mindset, one that seeks to overcome our brain’s inbuilt biases. These arise from the mental “rules of thumb”, known as heuristics, that we use to make decisions, and are responsible for our tendency to notice bad events rather than good ones, and to assume that some things are destined to happen. You may have already seen Ola Rosling’s work via his father’s TED talks. The first, given in June 2006 on “the best stats you’ve ever seen“, has now been viewed more than 16 million times. Last year, the trio behind Gapminder published Factfulness – a book that identifies the common pitfalls that make us see the world as a scary place. It became a global bestseller.For some reason, historically, it was beneficial to worry about everything, to see problems and plan for disaster. It was the way previous generations could survive. We are their offspring, so we tend to use the same tactics, except that we don’t need them anymore. I am not a researcher in these fields, but it seems like humans are predisposed to focus on the negative things we hear, to see problems. (Webmaster's comment: With all these mass killings by White Supremacists the world is better?)

9-4-19 A single severe head injury can trigger long-term brain damage
One major blow to the head is enough to trigger progressive brain deterioration and long-term cognitive decline in some people. We already know that repeated head knocks – like those sustained in boxing and American football – can lead to personality changes, cognitive problems and depression years later. This condition – known as chronic traumatic encephalopathy (CTE) – is associated with gradual build-up of a protein called tau in the brain. David Sharp at Imperial College London and his colleagues wondered if similar brain changes can occur after one bad head injury. To find out, they scanned the brains of 21 men and women who had a single major head injury 18 to 51 years ago in a car accident, assault or fall. They all experienced severe initial symptoms like loss of consciousness for more than 30 minutes, and many have since developed problems with thinking, memory and motivation. The scans revealed that 15 of the participants have unusually high levels of tau protein in their brains, particularly in the outer layers. This is probably because the outer layers are most vulnerable to external impacts, Sharp’s team writes. The amount of tau in their brains didn’t seem to relate to symptom severity, but the study may have been too small to detect this relationship, say the researchers. High levels of tau have also been found in the outer brain layers of former athletes with CTE, particularly in those who have had the most head blows. This is consistent with the idea that brain deterioration can come from either several relatively minor brain injuries or from a single particularly severe one, writes the team.

9-4-19 Vegetarian diet linked with 22 per cent lower risk of heart disease
Eating a vegetarian diet rather than consuming meat has been linked with a significantly lower risk of coronary heart disease. While the environmental case for going vegetarian is unequivocal and powerful, the long-term health impacts of adopting a vegetarian or vegan diet are still poorly understood. To help fill the gap, Tammy Tong at the University of Oxford and her colleagues grouped 48,000 people in the UK by diet and followed them over 18 years. The results showed vegetarians had a 22 per cent lower risk of heart disease than their meat-eating counterparts. The finding, which is in line with some previous research, could be explained by vegetarians generally having lower cholesterol levels. But the analysis has a sting in the tail: vegetarian diets were also associated with a 20 per cent high risk of stroke than that seen in meat-eaters. The reason could be vegetarians missing out on some nutrients only found in meat, such as the B12 vitamin. But that deficiency can be addressed with supplements, says Tong. While that might give people pause before joining the UK’s estimated 1.7 million vegetarians and vegans, Tong says it’s important to look at absolute numbers. Over a ten-year period in the cohort she studied, vegetarians had 10 fewer cases of heart disease per 1000 people than meat-eaters, but just three more cases of stroke per 1000. “You can say the lower risk of heart disease does outweigh the higher risk of stroke in this cohort,” she says.Mark Lawrence and Sarah McNaughton of Deakin University, Australia, writing in a commentary in the BMJ, say the stroke risk should be kept in perspective, as it is a result from just one study and the increase is modest relative to meat-eaters.

9-4-19 All languages, however different, convey information at the same rate
Human speech conveys information at 39 bits per second on average. That might not sound terribly impressive in an age where electronic devices exchange millions of bits of information per second, but it seems to be the optimum rate for people whatever language we speak. Francois Pellegrino’s team at the University of Lyon in France analysed 17 languages, from English to Japanese, that vary greatly in terms of the number of basic sounds, the number of syllables, the use of tones and so on. For instance, there are 7000 distinct syllables in English compared with just a few hundred in Japanese. The team worked out the information density of each language, in terms of bits of information per syllable. This varies from 5 bits per syllable for Basque to 8 bits per syllable for Vietnamese. Next, the team got 10 native speakers of each language – 170 people overall – to read 15 equivalent texts. What they found was that while the speech rate – in terms of syllables per second – varied from speaker to speaker, those speaking more information-dense languages speak more slowly on average. For instance, Basque was spoken at a rate of 8 syllables per second on average while Vietnamese was spoken at 5 syllables per second, making the rate at which information is conveyed similar for both. “There’s this pretty strong push to go for an optimal information rate,” says team member Dan Dediu. “We all have similar brains and we all have similar articulatory organs, so there are universal constraints.” Just what imposes these constraints isn’t clear. It might be due to the effort of speaking, or of understanding speech, or be related to the frequency of brainwaves, Dediu says.

9-4-19 This ancient Denisovan finger bone is surprisingly humanlike
Yet the extinct hominids had closer genetic ties to Neandertals than Homo sapiens. A newly described Denisovan finger fossil holds a skeletal surprise, adding to the mystery of this extinct Stone Age crowd. A decade ago, scientists found a tiny fragment of a fossil pinkie bone in Siberia’s Denisova Cave. That bone yielded the first known Denisovan DNA and helped identify the hominids (SN: 8/30/12). Now paleogeneticist E. Andrew Bennett of Paris Diderot University and colleagues say they’ve identified the rest of the finger bone, which comes from the right hand of a roughly 13-year-old female Denisovan. Unexpectedly, this ancient digit looks more like corresponding bones of ancient and recent humans than of Neandertals, the scientists report September 4 in Science Advances. Yet Denisovans, who inhabited parts of Asia from around 300,000 to 50,000 years ago, had closer genetic ties to Neandertals than to Homo sapiens (SN: 5/1/19). The new finding raises the possibility that other yet-to-be-found Denisovan body parts may be largely humanlike. (Aside from the finger, only teeth, a partial jawbone and part of a braincase have been found so far.) As a result, Bennett’s team recommends caution in trying to identify Denisovan fossils based on shape alone. Russian scientists unearthed the newly identified finger fossil in 2008 in Denisova Cave. Then they cut the specimen into two the next year and sent the pieces to separate DNA-research teams. Bennett’s group matched mitochondrial DNA extracted from one finger segment to mitochondrial DNA already taken from the smaller Denisovan finger fragment, indicating that the bones came from the same individual. Mitochondrial DNA is typically inherited from the mother.

9-4-19 540-million-year-old worm was first segmented animal that could move
An extinct creature that looked like a cross between a millipede and an earthworm was one of the first animals that could move under its own power. The animal has been named Yilingia spiciformis. It was up to 27 centimetres long and up to 2.6 cm wide. Its body was divided into many segments, each carrying two spiky appendages. It looked a bit like an ear of wheat. The fossils were found in the Dengying Formation in southern China. They are between 551 and 539 million years old. This was the Ediacaran period, when the first confirmed multicellular animals appear in the fossil record. Before the Ediacaran, life on Earth seems to have been almost entirely single-celled, but after the Ediacaran, complex plants and animals flourished. Alongside 35 fossils of Y. spiciformis, the rocks also yielded 13 trace fossils: tracks that were left behind by the animals as they moved along the sediment on the seabed. One body fossil was actually found right next to its tracks, offering hard evidence that Y. spiciformis was able to move. “It is the first segmented animal that has been shown to be capable of directional movement,” says Shuhai Xiao at Virginia Tech. Xiao says that Y. spiciformis isn’t quite the oldest animal that could move from A to B. “The first mobile animal is probably about 565 million years old,” he says. One such creature was the slug-like Kimberella, which could slither across the sea floor. Other Ediacaran animals like Dickinsonia could probably move in a less directed way, by letting the water current take them, says Xiao. The new fossils will help us understand how animals evolved the ability to move, says Xiao. “When we look at the animal family tree, clearly animals started as non-motile organisms,” he says. These early, stationary animals may have resembled modern sponges. “The question then becomes, when did animal motility evolve, and whether it evolved once or several times among animals.”

9-4-19 Healthy gut, happy mind: What to eat to boost how you feel
The deep connection between our guts and brains gives us ways to eat ourselves happier – and a few simple changes make all the difference, says dietician Megan Rossi. Megan Rossi is a research fellow at King’s College London and a dietician and founder of the Gut Health Clinic at Harley Street in London. Her background as a clinical dietician and sports nutritionist in Australia helped her realise the depth of the link between what we eat, the bacteria in our gut and how we feel, subjects she now researches at King’s. Her book Eat Yourself Healthy is published on 19 September. Megan will also be appearing at New Scientist Live in London on 12 October to talk about we can better look after our gut health. It made me laugh when you said in your book that “intimate kisses” can transfer bacteria between partners. Are there consequences? There are millions of bacteria in our saliva, so we’d like to see if these impact our partners’ health in some way. In observational studies, there’s an increased risk of being obese if you have an obese partner. Of course, this may just be down to your shared eating environment, but there’s a theory that you might also be sharing bacteria that are associated with obesity.It has been known for ages that there is a connection between our gut and brain via nerves, but now there is a new player, gut bacteria. They communicate with the brain in three different ways: they send signals up the vagus nerve directly into the brain; they influence immune cells in the gut, which produce a range of chemicals that affect the brain; and they produce chemicals that travel in the blood. Some can get through the blood-brain barrier to the brain. And it works in both directions.

9-4-19 Gut feeling: How a healthy microbiome helps beat stress and lift mood
The microbes in our guts have a surprising influence on our brains. Now we're understanding why – and how to use them to combat anxiety, stress and depression. REMEMBER the last time you had a stomach bug and just wanted to crawl into bed and pull up the covers? That is called “sickness behaviour” and it is a kind of short-term depression. The bacteria infecting you aren’t just making you feel nauseous, they are controlling your mood too. It sounds absurd: they are in your gut and your feelings are generated in your brain. In fact, this is just an inkling of the power that microbes have over our emotions. In recent years, such organisms in the gut have been implicated in a range of conditions that affect mood, especially depression and anxiety. The good news is that bacteria don’t just make you feel low; the right ones can also improve your mood. That has an intriguing implication: one day we may be able to manipulate the microbes living within our gut to change our mood and feelings. It is early days, but the promise is astounding. The World Health Organization rates depression and anxiety as the number one cause of disability, affecting at least 300 million people worldwide. The new findings challenge the whole paradigm of mental illness being caused by a chemical imbalance in the brain, and offer an alternative to drug treatment. You’ve probably heard of probiotics, but these are their new incarnation – psychobiotics. They could be about to change the mood of the planet. Bacteria have been associated with sickness almost since they were discovered 350 years ago by Dutch biologist and microscope pioneer Antonie van Leeuwenhoek. Only recently have we begun to understand that microbes also contribute to our health. They produce vitamins and help us eke out extra energy from otherwise indigestible food, for example. Most importantly, by outcompeting and directly battling pathogens, our home-grown microbes protect us from disease.

9-4-19 Pancreatic cancer tumors attack the blood vessels that deliver chemo drugs
New insights into how pancreatic cancer spreads could lead to more effective treatments. Pancreatic cancer is nearly impossible to treat. New research now shows this may be because its tumors destroy the surrounding blood vessels that doctors typically rely on to deliver anti-cancer drugs. Armed with this new knowledge, researchers have zeroed in on how the tumors kill neighboring blood vessel cells. When the team knocked out part of a molecular messaging system underlying the tumor’s deadly progression, its growth slowed, and the density of surrounding blood vessels increased both in mice and in human cells in a dish, the team reports August 28 in Science Advances. A drug that does the same thing in humans “could rescue the blood vessels around the tumor and allow us to deliver drugs to the patient that would shrink the tumor mass, which is currently impossible to do,” says Duc-Huy Nguyen, a molecular biologist at Weill Cornell Medicine in New York City, who did the research while at the University of Pennsylvania. Pancreatic cancer is among the deadliest cancers: More than 90 percent of the estimated 56,770 Americans who will be diagnosed with the disease in 2019 are predicted to die within five years. Cancer of this sweet potato–sized organ has long puzzled researchers. The tumors appear to spread via the bloodstream, yet the tumors themselves have little to no blood supply. Understanding how pancreatic cancer grows and spreads throughout the body has proven difficult because the pancreas is nestled deep in the belly, just behind the stomach. Monitoring a tumor or removing sections of it for study requires cutting the patient open and weaving through other vital organs, increasing the risk of infection or other complications.

9-4-19 Liquid mouth drops could one day protect people from peanut allergies
The treatment may rival a similar approach that involves swallowing the food. A no-fuss immune therapy involving liquid drops placed under the tongue could protect people with peanut allergies from reacting if exposed. Results from a small study of the treatment — called sublingual immunotherapy, or SLIT — rival those of a similar treatment that also builds allergy tolerance by exposing sufferers to small, daily doses of an allergen, researchers report September 4 in the Journal of Allergy and Clinical Immunology. But in that approach, called oral immunotherapy or OIT for short, doses are swallowed rather than administered under the tongue (SN: 11/18/18). The question with SLIT “was always about efficacy,” says Brian Schroer, director of allergy and immunology at Akron Children’s Hospital in Ohio, who was not involved with the research. The new study “shows it’s pretty much equivalent to OIT in terms of protection from accidental food exposures,” he says. SLIT’s delivery method through the mouth’s mucous membrane means that much smaller doses can be used than with the oral treatment, says Edwin Kim, a pediatric allergist and immunologist at the University of North Carolina’s School of Medicine in Chapel Hill. SLIT also produced milder side effects, such as a mouth itch that lasted for up to 15 minutes, compared with OIT, which occasionally has caused allergic reactions that required epinephrine, Kim and colleagues report. And while patients need a two-hour rest period after taking the oral treatment, those receiving a sublingual dose need only hold it under their tongues for two minutes. And “then you’re in the clear to go about your day,” Kim says.

9-3-19 Battle of Worcester artefacts unearthed for first time
Artefacts from the site of the final battle of the English Civil War have been unearthed for the first time. Musket balls, horse harness fittings and belt buckles were found at the Battle of Worcester site in Powick, Worcestershire. Historians have always known the area was the site of the 1651 battle, but it is the first time physical evidence has been recovered. The artefacts will now be analysed and recorded. Archaeologists were able to explore an area of land close to Powick Church while the Worcester Southern Link Road is being built. They had hoped to find artefacts as there is shot damage on the church tower, while Powick Bridge was reportedly the location of intense fighting. The 98 finds were buried deep at the bottom of a river valley and covered by flood deposits accumulated over hundreds of years since the battle. They included a powder container cap, which would have been the top of a flask that held gunpowder, and an impacted lead shot - a lead ball fired from a musket. The finds show the battlefield site was further south than previously thought. Archaeologists said different artefacts were found in different areas of the battlefield, reflecting the different types of troops that would have been fighting. For example, more pistol shots were found in one area, reflecting cavalry, while musket shots were found in another area, reflecting infantry. Richard Bradley, on-site lead archaeologist, said it was "fantastic" to be able to locate and map physical remains of the battle. "We are just outside the registered battlefield area but this is still a nationally significant site," Mr Bradley said. "The construction work has given us the opportunity to investigate the floodplain across which thousands of infantry and cavalry engaged, and to get down to the level where artefacts were deposited.

9-2-19 Bananas have benefited from climate change – but they won’t in future
Climate change has been relatively kind to banana suppliers so far – but in the decades to come, friend may turn to foe. Temperatures are likely to get so hot that the annual production gains enjoyed by banana suppliers will begin to drop. And in some places, total banana yields will begin to decline. Bananas are a staple crop for millions, and one of the world’s top 10 crops in terms of the cultivated area devoted to their growth and the calories they provide to the global population. For the past 60 years, annual yields have been increasing by 1.37 tonnes a hectare as the world warms, and now stand at about 10-40 tonnes per hectare. But a new study by Dan Bebber at the University of Exeter, UK, and his colleagues suggests that as climate change continues, annual yield gains will begin to slump. By 2050, they may be down to 0.19-0.59 tonnes per hectare. “Bananas can take it pretty hot,” says Bebber. “But some of our big suppliers are under serious threat, particularly in Latin America.” India and Colombia will be so badly affected that total annual banana yields will begin to fall, he says. Bebber and Varun Varma of the National Centre for Biological Sciences in Bangalore, India, built a model of optimal conditions for banana production, based on databases from 27 countries stretching back to 1961, combined with temperature and rainfall records. Globally, the ideal average temperature for the crop appears to be 26.7°C, but the best level varies from country to country. Temperatures in the future were assumed to follow two of the UN climate science panel’s worst scenarios. Bananas are cheap in high income countries, so producers are likely to be badly affected by any change in production yields.

9-2-19 'Mission Jurassic' fossil dinosaur dig closes for winter
Three full truck loads of dinosaur fossils were shipped out of the "Mission Jurassic" dig site in North Wyoming as scientists brought the 80-day excavation season to an end. The specimens included skeletal parts from giant herbivorous sauropods and meat-eating theropods. The fossils will now be cleaned to see precisely which species they represent. Mission Jurassic is a major undertaking involving researchers from the US, the UK and the Netherlands. It is led by The Children's Museum of Indianapolis (TCMI) which has taken out a 20-year lease on a square mile (260 hectares) of ranch land. The BBC was given special access to the site in July. The fossil beds exposed at the secret location in the Big Horn Basin record dinosaur activity around 150 million years ago - and the summer's work confirms the site is particularly rich. One three-tonne block of rock lifted on the final day last week was embedded with multiple remains all stacked one on top of the other. "Overall we must have moved something like 500-600 bones; it's just a huge amount of material we've been able to shift in one year," said Prof Phil Manning, a University of Manchester palaeontologist and TCMI scientist in residence. The Children's Museum has been working the site with teams from Manchester, London's Natural History Museum and Leiden's Naturalis Biodiversity Centre. They've been scraping back the layers in two pilot quarries. One of these appears to be a watering hole where various different animals congregated. Not only are their bones preserved in the sediments but so too are the footprints they made as they sploshed through muddy ground. "We have astounding trackways now - over a hundred individual tracks from different creatures. It's pretty cool because we see evidence of the animals when they were dead and when they were alive," Prof Manning told BBC News.

9-1-19 CRISPR could lead to gene-editing fix for a form of male infertility
Male mice with a mutation that prevented them producing any sperm have fathered offspring the natural way after a team in China fixed their infertility by CRISPR genome editing. The technique could one day help many infertile men around the world. “I think this study is very exciting,” says Sarah Vij, a male infertility specialist at Cleveland Clinic Foundation in the US, who was not involved in the work. “Most of us think this is the future for these men.” There are several known genetic mutations that prevent the stem cells in the testes giving rise to healthy sperm. Some men still have non-moving sperm cells in the testes that can be surgically extracted and injected into eggs. But this doesn’t always work, and children created this way risk inheriting the mutation that made their father infertile. So for decades biologists have been exploring ways of correcting these mutations. In 2015, for instance, one team showed that they could restore the ability of mice stem cells to produce healthy sperm by using CRISPR genome editing to correct the underlying genetic mutation. Now Xiaoyu Li’s team at the Affiliated Hospital of Guangdong Medical University has taken this work a step further by taking stem cells from a mouse, correcting the mutation and implanting them back in the same mouse. Four months later, the mice mated with females, and 9 out of 11 fathered healthy offspring. However, there is still a way to go before trying this in people. The biggest obstacle, says reproductive expert Geert Hamer of the University of Amsterdam, is that there is no reliable way of isolating human sperm stem cells. Another issue is that in some cases it might be necessary to kill off the mutant stem cells in the testes to prevent them competing with the corrected ones, Hamer says. This would likely require chemotherapy or radiation, so developing lab-grown sperm and using it for IVF might be a safer approach.

9-1-19 Giant virus has evolved its own kind of CRISPR to destroy invaders
The mimivirus is so enormous it has its own kind of CRISPR-like immune system to defend against the smaller viruses that attack it. A team in France has confirmed how it works by transferring the entire system to a bacterium and tweaking it to destroy a different target. While CRISPR has become famous as a tool geneticists can use for editing genomes, it evolved in bacteria as a way of defending against viruses. The bacteria “cannibalise” bits of DNA from the viruses that attack them and add this DNA to their own genomes. The CRISPR system allows the bacteria to recognise and destroy any matching viral DNA the next time they get attacked. In other words, CRISPR acts like an adaptive immune system. In 2016, Didier Raoult of Aix-Marseille University in France sparked controversy when he claimed that a giant virus called mimivirus had independently evolved its own adaptive immune system that works in a similar way to CRISPR, dubbed MIMIVIRE. Giant viruses are strange entities first identified in 2003. Like all viruses, they cannot multiply independently but rely on hijacking other organisms. But while most viruses are little more than protein shells containing DNA or RNA, giant viruses have lots of active cellular machinery inside them, such as protein-making factories. They are so complex they are even plagued by their own viruses, or virophages. The first virophage was discovered by Raoult in 2008. His team also discovered that one strain of mimivirus is immune to a virophage called zamilon. This mimivirus strain has bits of zamilon DNA integrated into its genome, which it uses to recognise and chew up the DNA of invading zamilon virophages. But critics questioned the claim that the mimivirus has its own kind of adaptive immune system. So Raoult has now transferred the MIMIVIRE system to the E. coli bacterium. Crucially, the team swapped the zamilon sequences for bits of a bacterial gene. When they activated MIMIVIRE, that bacterial gene got chewed up. “We changed the target,” says Raoult.

9-1-19 How a deer-tooth necklace helps us to better understand our ancestors
Ice Age Europe, approximately 20,000-13,500 years ago; a period known as the Magdalenian. The climate is gradually ameliorating after glaciers and cold temperatures reached their height in the Last Glacial Maximum. Despite this, the landscape is frozen, arid, and unforgiving for all who live within it. Dispersed and highly mobile hunter-gatherers populate this harsh environment. These Magdalenian people adapted to the landscape by using all available resources to create a rich and diverse material culture, which included tools, highly efficient hunting projectile weapons, tailored clothing, cave art, portable art, beads, and much more. All aspects of this culture depended on relationships with other human groups, and an intimate knowledge of animals that were a crucial resource during this period, enabling the Magdalenian people to survive. It is these relationships, how they were maintained by these people, and how they shaped past identities and social behaviors, that are the key to better understanding our ancestors' social lives and behaviors. During this period, around 19,000 years ago in southwestern France at a site called Saint-Germain-La-Rivière, an adult woman dies and is prepared for burial by members of her society. She is adorned with 70 red-deer teeth that were perforated by a flint tool to be used as beads; many of which have a unique engraved design and were smeared with red ocher. These beads provide a window into the period, giving an insight into the way our Magdalenian ancestors negotiated relationships, and the importance of this meshwork of relations to their survival. The burial context of these beads demonstrates how these relations took center stage in the social lives of Magdalenian people. Untangling the object biographies of these beads — the way they were made, used, and deposited — can reveal the creative ways our ancestors used objects to negotiate and embody intricate human-animal-object-landscape relationships. Insight into the "lives" of these beads can be achieved by contextualizing the successive stages of their biographies within the environmental and social conditions of the Magdalenian.


68 Evolution News Articles
for September 2019

Evolution News Articles for August 2019