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69 Evolution News Articles
for November 2018
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Nature cares only that you reproduce and raise the kids.
After you've done that get out of the way.

11-16-18 Walking backwards can boost your short-term memory
To go back in time, it might help to go backwards in space. Volunteers in a study did better in a memory test if they walked backwards before taking it – or if they simply imagined moving backwards. Aleksandar Aksentijevic at the University of Roehampton, UK, and colleagues asked 114 volunteers to watch a video in which a woman has her bag stolen by a passer-by. Ten minutes after watching the video, some of the participants were told to walk forwards or backwards 10 metres, while those in a control group stood in one place. Then they were asked 20 questions about the events in the video. The backward-walking group got two more answers correct on average than the forward-walkers and the non-walkers – a small improvement, but one that was statistically significant. A similar effect was found in five variations of the experiment. One of them involved a similar procedure, but tested how many words the volunteers could remember from a list. In others, participants simply imagined moving forwards or backwards, or watched a video filmed on a train, which created the impression of moving forwards or backwards. We are all used to thinking about time as a space that we move through, and using the language of spatial movement to talk about time. This study and others hint that the connection between time and space is more than a convenient analogy – it is intrinsic to the way the past is conceptualised in our minds

11-15-18 Catching up on sleep at weekends may aggravate period pain
Sleeping in on weekends may cause period pain by disrupting normal reproductive cycles, a study in female university students suggests. We already know that female shift-workers are more prone to irregular menstrual cycles, difficulties falling pregnant and miscarriages, possibly because their irregular schedules affect the circadian rhythms that control their hormone cycles. Yoko Komada at Meiji Pharmaceutical University in Japan and her colleagues wondered if social jetlag – a pattern of sleeping in on weekends to make up for early starts during the week – may have similar effects. To find out, they surveyed 150 female Japanese university students about their sleep habits and menstrual patterns. The students were defined as having social jetlag if the midpoint of their sleep was an hour or more later on their days off than on their university days. Those with social jetlag reported significantly more pain, bloating and behavioural changes during their periods. Moreover, the greater the social jet lag they had, the worse their symptoms were. These adverse health effects could not be explained by late-night drinking or smoking at the end of the university week, since almost none of the students drank alcohol and none smoked. Getting up later on days off may throw out the body’s circadian rhythms, which are reset daily by light exposure upon waking, says Jonathan Cedernaes at Uppsala University in Sweden. “In either social jet lag or shift work, you mistime when your body is expecting to sleep and be exposed to light,” he says.

11-15-18 Lyme and other tickborne diseases are on the rise in the U.S. Here’s what that means.
An infectious disease physician answers questions about the increase in cases. There’s no sign that ticks are backing down. A record high of 59,349 cases of tickborne diseases were reported in 2017 in the United States. That’s a 22 percent increase in cases — or roughly 11,000 more — than were reported in 2016, the Centers for Disease Control and Prevention announced on November 14. Lyme disease accounted for most of the reported diseases, with nearly 43,000 cases in 2017, up from over 36,000 in 2016. There were increases in all six tick-related illnesses reported, though, including Rocky Mountain spotted fever. Because underreporting is common, experts expect the actual number of cases is higher than what the data show. “The United States is not fully prepared to control these threats,” the agency said in statement. The Tick-Borne Disease Working Group, set up by Congress in 2016 to address the threats that ticks pose, also released its first report on November 14, with input from public health officials, scientists, patients and clinicians. Science News discussed the findings with the working group’s chairman, infectious disease physician John Aucott, who is also the director of the Lyme Disease Research Center at Johns Hopkins School of Medicine.

11-15-18 Mini ‘solar panels’ help yeast shine at churning out drug ingredients
Covering microbes with light-harvesting semiconductors boosted shikimic acid production. Bionic microbes outfitted with tiny semiconductor components can generate useful chemicals more efficiently than normal cells. Microorganisms like fungi are commonly used in biomanufacturing to convert simple carbon-based molecules, such as sugar, into a wide range of chemical ingredients for pharmaceuticals and other products. But much of a microbe’s carbon intake typically gets used to power the creature itself, cutting the amount available to form desired chemicals. In the new setup, described in the Nov. 16 Science, microbial cells are coated in semiconductor nanoparticles that absorb and transfer energy from sunlight to the cell, similar to the way rooftop solar panels supply energy to a house. That process allows the cell to funnel carbon it would normally use as a fuel toward its chemical output instead. Chemical and biological engineer Neel Joshi of Harvard University and colleagues tested this scheme using baker’s yeast cells covered in nanoparticles made of the semiconductor indium phosphide. Baker’s yeast consumes the sugar glucose to produce shikimic acid, which is used to make the flu medication Tamiflu. In lab experiments, cyborg microbes equipped with nanoparticles produced about three times as much shikimic acid as normal baker’s yeast fed the same amount of glucose.

11-15-18 Is the sex recession only for straight people?
When a trend makes the cover of The Atlantic, you know it's really arrived. That's surely the case with the "sex recession," the term Kate Julian coined in a blockbuster article to describe a phenomenon that social scientists have been tracking and puzzling over for years now. Americans — and not just Americans — are having less sex than they used to. A lot less sex. They're starting later and engaging with less frequency, with fewer people over a lifetime, and with less satisfaction. We may seem to the casual observer to be a sex-obsessed society, but it appears that impression is as accurate as someone's Instagram feed. And while there's some data to cheer about — a decline in teen pregnancy is surely a positive development, for example, as is the dramatic decline in new HIV infections — the overall picture is a depressing one, given how strongly correlated a positive sex life is with personal well-being. What is the explanation for this sustained decline? Cultural conservatives will predictably indict the continuing echoes of the now-50-years-old sexual revolution that cheapened intimacy and disrupted the purportedly natural order of family-formation. Feminists need only gesture at any given week's headlines to bring their own indictment of violent male entitlement as the root cause. In both cases, the blame falls on changes in the culture. The narrative satisfactions of such cultural explanations are obvious, which is why I'm instinctively inclined to look first for material explanations. And there are plenty on offer. Perhaps environmental pollutants are to blame for a drop in libido as they are plausibly to blame for a global drop in sperm count? Or perhaps it's the opposite, and the removal of lead from gasoline explains the drop in teen pregnancy as well as it explains the drop in teen criminality? Economic explanations are also ready to hand. Partly as a consequence of the Great Recession, a whole cohort of young adults have lived with their parents at much higher rates and for much longer into their 20s (and even 30s) than previous generations. It's hard to build a stable relationship under such conditions. Meanwhile, those fortunate enough to have good-paying jobs increasingly feel married to them, leaving little time to explore the depths of human companionship. Then there's technology, changing our habits and thereby our minds and brains. Are ubiquitous screens making us more distractible and depriving us of high-quality sleep? Has pornography-facilitated masturbation acted like a drug, blunting our drive to seek fulfilling erotic relationships? Is the sex recession a side effect of our widely-attested plague of anxiety and depression, or of the libido-dampening drugs prescribed to treat those conditions?

11-15-18 Exclusive: A new test can predict IVF embryos’ risk of having a low IQ
A new genetic test that enables people having IVF to screen out embryos likely to have a low IQ or high disease risk could soon become available in the US. THE prospect of creating intelligent designer babies has been the subject of ethical debate for decades, but we have lacked the ability to actually do it. That may now change, thanks to a new method of testing an embryo’s genes that could soon be available in some IVF clinics in the US, New Scientist can reveal. The firm Genomic Prediction says it has developed genetic screening tests that can assess complex traits, such as the risk of some diseases and low intelligence, in IVF embryos. The tests haven’t been used yet, but the firm began talks last month with several IVF clinics to provide them to customers. For intelligence, Genomic Prediction says that it will only offer the option of screening out embryos deemed likely to have “mental disability”. However, the same approach could in future be used to identify embryos with genes that make them more likely to have a high IQ. “I think people are going to demand that. If we don’t do it, some other company will,” says the firm’s co-founder Stephen Hsu. For many years, it has been possible to do simpler genetic tests on embryos as part of IVF. For example, parents at risk of having a child with cystic fibrosis have the option to undergo IVF and select an embryo that doesn’t carry the gene behind the condition. It is also possible to screen for several other conditions caused by a single gene, as well as those caused by chromosomal abnormalities, such as Down’s syndrome. However, most medical conditions are influenced by hundreds of genes, which has made it impossible to screen out embryos with a high risk of heart disease, for example, or select embryos with a low likelihood of experiencing depression. This is true for traits like intelligence too.

11-15-18 New techniques may soon make designer babies a reality – are we ready?
IT IS hard to think of an area of science more controversial than the genetics of intelligence. Now it is about to get exponentially more contentious. For a long time, DNA testing couldn’t tell us anything useful about someone’s IQ or any other traits affected by multiple genes, such as diabetes or cancer risk. But new “polygenic” techniques for analysing many genetic regions at once have begun to make this possible. This week, we report on the first company offering fertility clinics a test for screening IVF embryos for disease risk and low intelligence (see “Exclusive: A new test can predict IVF embryos’ risk of having a low IQ”). With this news, it is unlikely to be long before some clinic, somewhere, starts using a similar approach to offer prospective parents the ability to pick out embryos that look most genetically promising for a high IQ. As if this isn’t controversial enough, it may only be the beginning. As our understanding of traits governed by multiple genes grows, it may also become possible to screen for embryos that are more or less likely to have a range of other features, be it sexuality, autism or susceptibility to depression. We already live in a world where wealthy individuals are willing to cross borders to pay for procedures at the sharpest edge of fertility research. The first baby created using a particular three-parent technique was born two years ago to Jordanian parents helped by US scientists working in Mexico, for example. While many prospective parents won’t want to genetically fine-tune their children this way, the idea of a near-designer baby will undoubtedly appeal to some. The desire to maximise a future child’s intelligence, mental health or physical attractiveness could be enough to prompt couples with no fertility problems to seek IVF, just to have this opportunity.

11-15-18 Life may have begun with cells made wholly from simple proteins
Did life begin in a world of proteins? It’s a minority view among origin-of-life researchers but it just got a boost. Researchers have built model cells out of nothing but simple proteins, and those cells can host some of the crucial processes of life. The small compartments within living cells are normally made from lipids, but in 2014, Stefan Schiller of the Albert Ludwig University of Freiburg in Germany and his colleagues made them using proteins instead. “So we asked the question if these ‘organelles’ also represent a plausible prebiotic protocell model,” he says. Proteins are built from long chains of amino acids. Schiller’s team made simple chains just five amino acids long. There are hundreds of naturally occurring amino acids, but the researchers used only seven kinds in their experiment to keep the approach simple and more likely to have occurred spontaneously on early Earth. The chains readily clumped together into spherical containers, which the team describe as “protocells”. This happened in pure water and in water with substances dissolved in it or mixed with alcohol. The protocells survived temperatures up to 100 °C, as well as being mixed with strong acids and alkalis. That implies they could endure “conditions imagined to be present on the early Earth”, says Schiller. The young planet was bombarded with meteorites and may have had a lot of active volcanoes. The team has also found that the protocells have a number of life-like properties. They can house large molecules over periods of weeks, just as living cells must play host to DNA and other substances. This included phospholipids, which most modern cells are made of. They also found that two protocells can fuse together to form one.

11-15-18 Prefer tea or coffee? It may be down to your genes for bitter tastes
Whether you prefer drinking tea or coffee may come down to your genes.Tea and coffee contain bitter components that contribute to their pleasant taste. Both drinks contain bitter-tasting caffeine, while coffee contains another bitter molecule called quinine, which is also found in tonic water. Previous research has found that people taste bitter flavours like caffeine, quinine and an artificial substance called propylthiouracil differently according to the types of taste receptor genes they have. To find out if this variation influences preference for tea or coffee, Daniel Hwang at the University of Queensland in Australia and his colleagues studied the relationship between taste receptor genes and tea and coffee consumption in over 430,000 men and women aged 37 to 73 in the UK. The participants with gene variants that made them taste caffeine more strongly were 20 per cent more likely than the average person to be heavy coffee drinkers, meaning they drank more than 4 cups per day. At the same time, these caffeine “super-tasters” were less likely to drink tea, says Hwang. This may be because people who are better at detecting caffeine are more prone to becoming addicted to its stimulant effects, and coffee contains more caffeine than tea. “But future studies are needed to investigate this,” says Hwang. In contrast, participants with gene variants that made them more sensitive to the tastes of quinine and propylthiouracil were 4 and 9 per cent more likely than the average person to be heavy tea drinkers respectively, meaning they drank more than 5 cups per day. They were also less likely to drink coffee.

11-15-18 Coffee or tea? Your preference may be written in your DNA
Genetic variants may confer sensitivity to the flavor of caffeine or other bitter chemicals. Whether people prefer coffee or tea may boil down to a matter of taste genetics. People with a version of a gene that increases sensitivity to the bitter flavor of caffeine tend to be coffee drinkers, researchers report online November 15 in Scientific Reports. Tea drinkers tended to be less sensitive to caffeine’s bitter taste, but have versions of genes that increase sensitivity to the bitterness of other chemicals, the researchers found. It’s long been thought that people avoid eating bitter foods because bitterness is an indicator of poison, says John Hayes, a taste researcher at Penn State who was not involved in the study. The coffee and tea findings help challenge that “overly simplistic ‘bitter is always bad, let’s avoid it’” view, he says. In the new study, researchers examined DNA variants of genes involved in detecting the bitter taste of the chemicals, caffeine, quinine — that bitter taste in tonic water — and propylthiouracil (PROP), a synthetic chemical not naturally found in food or drink. Other bitter components naturally in coffee and tea may trigger the same taste responses as quinine and PROP do, Hayes says. Researchers in Australia, the United States and England examined DNA from more than 400,000 participants in the UK Biobank, a repository of genetic data for medical research. Participants also reported other information about their health and lifestyle, including how much tea or coffee they drink each day.

11-14-18 We’ve got thinking all wrong. This is how your mind really works
From unconscious biases to advertising, the idea we can think fast or slow is influential, but it may be mistaken. Here’s how to think better. A bat and a ball together cost $1.10. The bat costs $1 more than the ball. How much does the ball cost? If you instantly guessed 10 cents, you’re in smart company: more than half of students at Harvard University and MIT jumped to the same conclusion. But you’d be wrong – the answer is actually 5 cents. For years, this puzzle has been held up as the perfect example of the way we think being ruled by two types of mental processes: fast and intuitive, versus slow and analytical. If you arrived at the wrong answer before you had time to really ponder the problem, you might blame it on intuitive thinking leading you to make a snap judgement before slower, rational thinking had kicked in. This idea that our thoughts can be split into two distinctive camps has become so popular it now influences many areas of everyday life. Marketeers try to tap into our automatic impulses with emotive adverts and special offers, while governments attempt to appeal to our deliberative sides, by doing things like putting calorie counts on menus. These “nudges” are often based on the assumption that fast, intuitive thinking is likely to get you into trouble, so we need to cultivate the slower kind. The US National Academies of Sciences, Engineering, and Medicine and the World Bank have both issued reports urging decision-makers to use the slower type of thinking to avoid the expensive, or deadly, mistakes of the other form. But a more complex picture of our mental processes is beginning to emerge. Categorising all our thoughts as one of these two types might in fact be leading us astray on all sorts of policies and practices. Armed with a new understanding of how we make decisions, we could all benefit.

11-14-18 We’ve discovered a whole new defence system against germs in our noses
IT’S been right inside our noses all along. When cells in the nose sense potential invaders, they release tiny sacs that fight them off and prime other cells to resist an onslaught. “We have demonstrated in a live patient that the immune system goes and attacks pathogens before they get into the body,” says Benjamin Bleier, a sinus surgeon at the teaching hospital Massachusetts Eye and Ear. “It is the only example of this I know of.” The nose is a crucial frontier: every breath we take may contain dangerous bacteria. So the cells lining the nasal cavity secrete a mucus that traps tiny particles. Hairs on the surface of these cells, called cilia, beat to move the mucus along. What’s surprising, says Bleier, is that instead of being swept forwards so it can be rapidly expelled, the mucus is swept backwards towards the throat. “You swallow it, and then the gut deals with it from there.” Bleier’s team and other researchers have recently found that, as well as secreting mucus, the cells of the nasal cavity release billions of tiny sacs called exosomes. Once in the mucus, these sacs can go on to fuse with other cells, delivering cargo such as proteins or RNA. This made Bleier and his colleagues suspect that exosomes are part of a previously unknown defence system. Now, after studying tissue in the lab and people undergoing nasal surgery, the researchers have strong evidence for this idea. They found that when cells at the front of the nose are exposed to a potentially dangerous bacterium, the number of exosomes released into the mucus doubles within 5 minutes. Their experiments suggest that exosomes can kill pathogens directly, although we don’t yet know how (Journal of Allergy and Clinical Immunology, doi.org/cwzw). “They are as powerful at killing bacteria as an antibiotic,” Bleier says.

11-14-18 The Galapagos of the Indian Ocean: Voyage to a forgotten paradise
Celebrated for their biodiversity, the islands of Socotra could unlock secrets of humans' journey out of Africa – but war and weather hamper the journey there. I HADN’T thought a scientific expedition would involve cockroaches or pirates, and certainly not both. And yet there we were, our team of four, sailing through a part of the Indian Ocean synonymous with Somali piracy, aboard a wooden cargo ship filled with a population of many thousands of grudging insects. We shared our sweaty cabin with a crew of 12 Gujarati sailors. In between watching for other vessels and clambering among the bags of cement on deck, our three days at sea were punctuated only by visits to the ship’s “toilets”: two wooden boxes strapped to the outside of the hull. Glamorous it wasn’t, but none of us would have wished to be anywhere else. We were on our way to the Socotra archipelago. Largely unknown in the wider world, this group of islands is a UNESCO World Heritage Site on account of its rich endemic flora and fauna. More than a third of its 800-plus plant species are unique to Socotra, whose westernmost island is just 100 kilometres from Somalia and the Horn of Africa. Some 400 kilometres to the north is Yemen, to which the territory belongs. With both countries torn apart by civil war, getting there isn’t easy. But that’s no reason not to try. Our team’s leader was archaeologist Ella Al-Shamahi of University College London. She was in search of secrets about our ancestors’ migration out of Africa that might lie in caves on the archipelago’s main island, also called Socotra. I’m an author and film-maker, and my job was to digitally map the major thoroughfares and tracks that cross the island. The archipelago has been prized for its unique resources for at least two millennia, and it is said to have supplied much of the ancient world with frankincense and aloes used in perfumes and medicines. But the volume of scientific work done there is a mere fraction of what has been possible in the few comparable places on Earth. It had seemed like increased political stability in Yemen in the 1990s would improve things, but now the geopolitics of the region looks to be closing the door once more. Add in the increasingly extreme and frequent cyclones that hit its shores, and Socotra’s future as a refuge of natural and cultural heritage is far from assured.

11-14-18 Skull damage suggests Neandertals led no more violent lives than humans
Some 200 skulls show similar rates of damage between humans and our evolutionary cousins. Neandertals are shaking off their reputation as head bangers. Our close evolutionary cousins experienced plenty of head injuries, but no more so than late Stone Age humans did, a study suggests. Rates of fractures and other bone damage in a large sample of Neandertal and ancient Homo sapiens skulls roughly match rates previously reported for human foragers and farmers who have lived within the past 10,000 years, concludes a team led by paleoanthropologist Katerina Harvati of the University of Tübingen in Germany. Males suffered the bulk of harmful head knocks, whether they were Neandertals or ancient humans, the scientists report online November 14 in Nature. “Our results suggest that Neandertal lifestyles were not more dangerous than those of early modern Europeans,” Harvati says. Until recently, researchers depicted Neandertals, who inhabited Europe and Asia between around 400,000 and 40,000 years ago, as especially prone to head injuries. Serious damage to small numbers of Neandertal skulls fueled a view that these hominids led dangerous lives. Proposed causes of Neandertal noggin wounds have included fighting, attacks by cave bears and other carnivores and close-range hunting of large prey animals.

11-14-18 A massive crater hides beneath Greenland’s ice
Whether the impact is related to a period of cooling called the Younger Dryas is unknown. There’s something big lurking beneath Greenland’s ice. Using airborne ice-penetrating radar, scientists have discovered a 31-kilometer-wide crater — larger than the city of Paris — buried under as much as 930 meters of ice in northwest Greenland. The meteorite that slammed into Earth and formed the pit would have been about 1.5 kilometers across, researchers say. That’s large enough to have caused significant environmental damage across the Northern Hemisphere, a team led by glaciologist Kurt Kjær of the University of Copenhagen reports November 14 in Science Advances. Although the crater has not been dated, data from glacial debris as well as ice-flow simulations suggest that the impact may have happened during the Pleistocene Epoch, between 2.6 million and 11,700 thousand years ago. The discovery could breathe new life into a controversial hypothesis that suggests that an impact about 13,000 years ago triggered a mysterious 1,000-year cold snap known as the Younger Dryas (SN: 7/7/18, p. 18). Members of the research team first spotted a curiously rounded shape at the edge of Hiawatha Glacier in northwest Greenland in 2015, during a scan of the region by NASA’s Operation IceBridge. The mission uses airborne radar to map the thickness of ice at Earth’s poles. The researchers immediately suspected that the rounded shape represented the edge of a crater, Kjær says.

11-14-18 Greenland ice sheet hides huge 'impact crater'
What looks to be a large impact crater has been identified beneath the Greenland ice sheet. The 31km-wide depression came to light when scientists examined radar images of the island's bedrock. Investigations suggest the feature was probably dug out by a 1.5km-wide iron asteroid sometime between about 12,000 and three million years ago. But without drilling through nearly 1km of ice to sample the bed directly, scientists can't be more specific. "We will endeavour to do this; it would certainly be the best way to get the 'dead fish on the table' (acknowledge the issue, rather than leaving it), so to speak," Prof Kurt Kjær, from the Danish Museum of Natural History, told BBC News. If confirmed, the crater would be the first of any size that has been observed under one of Earth's continental ice sheets. The discovery is reported in the journal Science Advances. The putative impact crater is located right on the northwest margin of the Greenland Ice Sheet, underneath what is known as Hiawatha Glacier. Additional high-resolution radar imagery gathered by Prof Kjær's team clearly shows a circular structure that is elevated at its rim and at its centre - both classic traits. But because the depression is covered by up to 980m of ice, the scientists have so far had to rely on indirect studies. Meltwaters running out from under Hiawatha Glacier into the Nares Strait carry sediments from the depression. In these sediments are quartz grains which have been subjected to enormous shock pressures, of the type that would be experienced in an impact. Other river sediments have revealed unusual ratios in the concentrations of different metals. "The profile we saw was an enrichment of rhodium, a depletion of platinum, and an enrichment of palladium," explained team-member Dr Iain McDonald, from Cardiff University, UK.

11-14-18 There is no fundamental difference between male and female brains
A lasting desire to find differences in how male and female brains work serves to affirm gender stereotypes, not explain them, says Dean Burnett. A study claiming to show “very clear” differences between the brains of men and women was widely reported this week, as such studies invariably are. Yet a close look at the details shows that if any differences exist they are anything but clear. Despite the large sample size – half a million people – there is much to find fault with the study, from the simple data collection method (a list of 10 agree/disagree questions completed online) to the application of questionable theories and assumptions. These include the empathising-systemising brain theory (the idea that all brains tend towards either empathy or analysis on a binary scale) and the “extreme male” theory of autism, which suggests that typical autistic traits are actually inherently male traits, taken to extremes of expression. The study, published in PNAS, is just the latest – and certainly won’t be the last – in a long line of findings that are trumpeted in the media as “proving” that male and female brains are inherently different. The actual evidence falls way short of such claims. Distinctions do exist. Men and women have genetic differences due to the sex chromosomes, are regulated by different hormones during development, and have distinct anatomical differences. All of this is reflected in the structure of the brain. But whether these have any direct and significant impacts on the functioning of the mature adult brain is a lot harder to determine. There are just too many other factors and variables that can affect how we use our brains, which cannot be screened out by modern research methods, no matter how rigorous.

11-14-18 Modern lifestyles shaped our evolution only a few thousand years ago
ARE humans still evolving? Because evolution usually takes many generations, it is hard to tell. But two new genetic studies reveal DNA changes that took hold within the last few thousand years, suggesting that modern lifestyles have recently shaped our evolution – and are probably still doing so. “During a short time, human genomes have changed a lot,” says Irina Morozova of the University of Zurich in Switzerland. “We think these changes are driven by human civilisation.” Both studies looked for evidence of evolution favouring some DNA sequences over others, a process called selection. Morozova and her colleagues compared the genomes of 150 Europeans from between 5500 and 3000 years ago with those of 305 modern Europeans descended from them. This allowed the team to identify various processes that evolution has acted on in Europeans within the past 6000 years (Molecular Biology and Evolution, doi.org/gfjj53). The team found changes over time in the way that the body metabolises carbohydrates. Morozova suggests these happened when societies began farming, prompting a switch from a meat-heavy, hunter-gatherer diet to a starchier, more sugary one. She thinks human metabolism is still evolving, and may keep doing so for millennia. “It’s not like we’re completely adapted to this.” There was evidence of evolutionary changes in several aspects of the immune system, too. It’s not clear what these changes do, but they could have been a response to exposure to new diseases some 6000 years ago, when people began living in more crowded conditions and spending more time with livestock. But two processes stood out as showing very few evolutionary changes over the same period of time. These are how egg cells form, and long-term potentiation, a process in the brain that aids learning by strengthening the connections of commonly used neural pathways. It looks as if both have been protected from changing, says Morozova.

11-14-18 Sound-absorbent wings and fur help some moths evade bats
Checkered scales on wings and furry bellies let the insects avoid detection. Some moths aren’t so easy for bats to detect. The cabbage tree emperor moth has wings with tiny scales that absorb sound waves sent out by bats searching for food. That absorption reduces the echoes that bounce back to bats, allowing Bunaea alcinoe to avoid being so noticeable to the nocturnal predators, researchers report online November 12 in the Proceedings of the National Academy of Sciences. “They have this stealth coating on their body surfaces which absorbs the sound,” says study coauthor Marc Holderied, a bioacoustician at the University of Bristol in England. “We now understand the mechanism behind it.” Bats sense their surroundings using echolocation, sending out sound waves that bounce off objects and return as echoes picked up by the bats’ supersensitive ears (SN: 9/30/17, p. 22). These moths, without ears that might alert them to an approaching predator, have instead developed scales of a size, shape and thickness suited to absorbing ultrasonic sound frequencies used by bats, the researchers found. The team shot ultrasonic sound waves at a single, microscopic scale and observed it transferring sound wave energy into movement. The scientists then simulated the process with a 3-D computer model that showed the scale absorbing up to 50 percent of the energy from sound waves. What’s more, it isn’t just wings that help such earless moths evade bats. Other moths in the same family as B. alcinoe also have sound-absorbing fur, the same researchers report online October 18 in the Journal of the Acoustical Society of America.

11-14-18 Ancient Greek city Tenea found by archaeologists
Archaeologists in Greece believe they have found the lost city of Tenea, thought to have been founded by captives of the legendary Trojan War. They said they had discovered the remains of a housing settlement, jewellery, coins and several burial sites in the southern Peloponnese area. Until now, archaeologists had a rough idea of where the city might have been located but had no tangible proof. The items date from 4th Century BC to Roman times. Excavation work around the modern-day village of Chiliomodi began in 2013, and "proof of the existence" of Tenea emerged in work carried out in September and early October this year, officials said. Carefully-constructed walls as well as clay, stone and marble floors were uncovered. Around 200 rare coins, including one designed to pay for the journey to an afterlife, were also found. Seven graves - including one containing the remains of a woman and child - were unearthed, adorned with vases and jewellery. Lead archaeologist Elena Korka told the Associated Press that the discoveries suggested the citizens of Tenea had been "remarkably affluent". She said the city would have been located on a key trade route between the main cities of Corinth and Argos in the northern Peloponnese. "(The city) had distinctive pottery shapes with eastern influences, maintained contacts with both east and west... and had its own thinking, which, to the extent that it could, shaped its own policies," she told the AP. Little is known about Tenea, but legend has it that it was founded by Trojans who had been captured by King Agamemnon of Mycenae during his war with Troy in the 12th or 13th Century BC. The city is thought to have flourished during the Roman era but may have been abandoned by the 4th Century AD.

11-13-18 U.S. cases of a polio-like illness rise, but there are few clues to its cause
The CDC has confirmed 90 cases of acute flaccid myelitis out of 252 suspected cases. The cause of a rare polio-like disease continues to elude public health officials even as the number of U.S. cases grows. Confirmed cases of acute flaccid myelitis cases have risen to 90 in 27 states, out of a possible 252 under investigation, the U.S. Centers for Disease Control and Prevention announced November 13. That’s up from 62 confirmed cases out of 127 suspected just a month ago (SN Online: 10/16/18). There were a record 149 cases in 2016. “I understand parents want answers,” Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases in Atlanta, said at a news conference. The agency continues to investigate the disease, which causes weakness in one or more limbs and primarily affects children. But “right now the science doesn’t give us an answer,” she said. A deep dive into 80 of the confirmed cases offered some details about the course of AFM. In most, fever or respiratory symptoms like coughing and congestion, or both, preceded limb weakness by three to 10 days. Most cases involved weakness in an upper limb, researchers report online November 13 in the Morbidity and Mortality Weekly Report. Only two samples of cerebrospinal fluid — the clear fluid that bathes the brain and spinal cord — tested positive for a pathogen, each for a different enterovirus. Since 2014, when the first big outbreak of AFM occurred, most AFM spinal fluid samples haven’t produced a culprit, Messonnier said. The body may clear the pathogen or it hides in tissues, she said, or the body’s own immune response to a pathogen may lead to spinal cord damage.

11-13-18 How mammoths competed with other animals and lost
Human hunters helped wipe out mammoths, mastodons and gomphotheres. The Gray Fossil Site, a sinkhole in northeastern Tennessee, is full of prehistoric treasures. Between 7 million and 4.5 million years ago, rhinoceroses, saber-toothed cats and other creatures, even red pandas, perished here by the edge of a pond. But that bounty of fossils pales next to the site’s biggest find: a mastodon’s skeleton, nearly 5 million years old, preserved in exquisite detail all the way down to its ankle bones. “It is just fantastic,” says Chris Widga, a paleontologist at East Tennessee State University in nearby Johnson City. The ancient elephant relative became known as Ernie because it was enormous, calculated soon after its 2015 discovery to have weighed 16 tons in life. The name came from musician Tennessee Ernie Ford, known for the coal-mining song “Sixteen Tons.” Since then the researchers have revised the mastodon’s weight down to 10.5 tons, says Widga, but the name stuck. Ernie is still the biggest mastodon ever found in North America. He would have dwarfed today’s large African elephants, which average up to six tons. Excavators are working to dig up the rest of Ernie’s bones before this winter, with an eye to reassemble the ancient beast, the researchers reported in October in Albuquerque at a meeting of the Society of Vertebrate Paleontology. Ernie is a jaw-dropping example of the ancient elephants that once roamed Earth. Scientists have found the remains of mastodons and their relatives, the mammoths, throughout the Northern Hemisphere — from huge tusks buried in the Alaskan permafrost to mummified baby mammoths in Siberia (SN Online: 7/14/14).

11-12-18 Diabetes Rates Rise in 18 States in Past Decade
The percentage of adults diagnosed with diabetes at some point in their lives has risen in 18 U.S. states in less than a decade, according to a comparison of Gallup-Sharecare Well-Being Index data from 2016-2017 versus 2008-2009 data. Diabetes rates did not decline in any states over the same period. Among the 18 states with reported increases in their diabetes rates, five experienced increases of at least two percentage points: West Virginia, Louisiana, Hawaii, Rhode Island and South Carolina. The remaining states with statistically significant increases are Arizona, Arkansas, California, Colorado, Georgia, Idaho, Indiana, Kansas, Missouri, New Mexico, Ohio, Tennessee and Texas. Nationwide, the diabetes rate rose to 11.5% in 2016-2017, up 0.7 percentage points compared with the 10.8% measured in 2008-2009 and representing a net increase of about 1.7 million U.S. adults who report having been diagnosed with the disease over that time.

  • No states have experienced declines in their diabetes rates since '08-'09
  • Obesity has climbed in 34 states over same period while declining in none
  • Rising diabetes linked to rising obesity among states

11-12-18 An extinct monkey evolved to live like a sloth in the Caribbean
About 11 million years ago, monkeys somehow crossed the sea from South America to the island of Jamaica in the Caribbean. There they evolved into a new species that was unlike any other known monkey. It’s a striking example of how living on an island can transform a species. The details have been revealed by preserved DNA. The first remains of Xenothrix mcgregori were discovered in Long Mile Cave, Jamaica in 1920. The few bones found reveal a highly unusual monkey, with relatively few teeth and leg bones similar to those of a rodent. “What they suggest is a very slow-moving, perhaps even sloth-like lifestyle, which is perhaps not unexpected in an animal living on an island with few predators other than large birds,” says Ross MacPhee of the American Museum of Natural History in New York. Some extinct Madagascan lemurs also evolved a similar slow-moving lifestyle. Ever since it was described in 1952, X. mcgregori has been an enigma. It was related to South American monkeys, but it was unclear which group it belonged to or when its ancestors reached Jamaica. Several suggestions had been made based on the bones, but the monkey was so unusual it was impossible to be sure. “It’s been all over the place,” says MacPhee. To clear up the mystery, MacPhee and his colleagues obtained DNA from two preserved X. mcgregori bones. They recovered the entire mitochondrial genome – which animals only inherit from their mothers – and seven chunks of the nuclear genome. The team compared these samples of DNA with the equivalent sequences from 15 different groups of South American primate. They found that X. mcgregori belonged to a group called the titi monkeys. These monkeys live in forests, eat fruit and do not have prehensile tails.

11-12-18 Mystery monkey: history of unique Xenothrix fossil revealed
A mysterious extinct monkey from Jamaica that is unlike any other in the fossil record has South American roots, according to new evidence. DNA extracted from fossilised bones suggests the monkey first colonised the island 11 million years ago. It had no predators there and it evolved strange features not seen in living monkeys today. But the animal went extinct a few hundred years ago, likely due to hunting and habitat loss. Scientists say the discovery highlights how vulnerable unique island animals are to extinction. "It was a really weird animal indeed," Prof Samuel Turvey from international conservation charity, Zoological Society of London (ZSL), told BBC News. "Possibly with legs like a rodent; body maybe like a slow loris. Because it's so weird no-one's been able to agree what it was related to." The researchers extracted ancient DNA from the fossilised cave bones of the Jamaican monkey, Xenothrix mcgregori. DNA evidence shows it was a type of titi monkey with some unusual morphological features, not a wholly distinct branch of evolution. "Evolution can act in unexpected ways in island environments, producing miniature elephants, gigantic birds, and sloth-like primates," said Dr Ross MacPhee of the American Museum of Natural History. Titi monkeys are small tree-dwelling animals found across tropical South America, with long soft red, brown, grey or black fur. They are active during the day, and very vocal, with an elaborate system of communication. Xenothrix's ancestors likely reached Jamaica from South America after being stranded on natural rafts of vegetation that were washed out of the mouths of rivers.

11-12-18 Earliest known animal might have inflated its body like a balloon
Have we misunderstood the first known animal? Dickinsonia, a weird organism from half a billion years ago, may have inflated its body to feed. The strategy is not seen in animals today, which raises questions about whether Dickinsonia really belongs in the animal kingdom after all. Dickinsonia is one of a bunch of enigmatic organisms called the Ediacarans that lived a few tens of millions of years before familiar animals like sponges began forming fossils. The Ediacarans have sometimes been interpreted as a failed evolutionary experiment, unlike anything alive today. But recently palaeontologists have become more confident that they were animals, with Dickinsonia singled out in particular as a candidate for the earliest known animal we have a fossil of. But if Dickinsonia was an animal, it may have been a very odd one, according to Nicole Law and Scott McKenzie at Mercyhurst University, Pennsylvania. Dickinsonia fossils look a bit like round flat ribbed blobs, some are about a metre in length but all no more than a few millimetres thick. Law and McKenzie have studied unusual radial scratch lines in the rock fringing one of the fossils and say they suggest that the organism was larger in life and then shrank after it died, leaving scratch lines in the sand beneath its body as it shrivelled up. “About 21 per cent of the total fossil area is taken up by this fringe,” says Law. She thinks that whilst alive Dickinsonia was longer, wider and taller than our fossils suggest. Its body was inflated like a balloon, and most fossils show it in a smaller and thinner deflated state.

11-12-18 We’ve discovered a whole new defence system against germs in our noses
It’s been right behind our noses all along but we’ve only just discovered it. When the cells inside your nose sense danger, they release billions of tiny sacs filled with bacteria-killing weapons into the mucus lining. These sacs not only kill bacteria directly, they also warn other cells of the danger and even help arm them against the invaders. This defence system has never been identified before. “We have demonstrated in a live patient that the immune system reaches outside of the body, and actually goes and attacks pathogens before they get into the body,” says Benjamin Bleier, a sinus surgeon at the teaching hospital Massachusetts Eye and Ear. “It is the only example of this I know of.” The nose is a crucial frontier. Every breath we take may contain dangerous bacteria. So the cells lining our nasal cavity secrete a mucus that traps tiny particles. Hairs on the surface of these cells, called cilia, beat back and forth to move the mucus along. What’s surprising, says Bleier, is that instead of being swept forwards into the nose so it could be rapidly expelled from the body, the mucus is swept backwards towards the throat. “You swallow it and then the gut deals with it from there,” says Bleier. Bleier’s team and other researchers have recently found that, as well as secreting mucus, the cells of the nasal cavity also release billions of tiny sacs called exosomes. After being released into the mucus, these sacs can go on to fuse with other cells, delivering cargo such as proteins or RNA.

11-11-18 DR Congo Ebola outbreak 'worst' in country's history
The latest outbreak of the Ebola virus in the Democratic Republic of Congo is the worst in the country's history, the health ministry says. Almost 200 people have died since August, officials say, with more than 300 confirmed or probable cases. A vaccination programme has so far inoculated about 25,000 people. Congo has suffered long years of instability and efforts to relieve the disease have been hampered by attacks on medical workers. "At this point, 319 cases and 198 deaths have been registered," health minister Oly Ilunga said. "In view of these figures, my thoughts and my prayers go to the hundreds of families grieving, to the hundreds of orphans and the families which have been wiped out." About half the victims were from Beni, a city of 800,000 in the North Kivu region, the national health authority said. The current outbreak is the tenth Congo has suffered and the worst since Congo's first epidemic in 1976, so early in the disease's history it had yet to be named. The outbreak in 1976 of what was then an unknown disease in a remote part of Congo sparked terror, but was brought under control by experts quickly identifying the virus' nature and using quarantines. Ebola is spread via small amounts of bodily fluid and infection often proves fatal. Early symptoms are flu-like, followed by vomiting, diarrhoea, a rash and internal and external bleeding. (Webmaster's comment: There are 7.7 Billion people. The largest food source for bacteria and viruses in the whole world.)

11-10-18 A potent fish oil drug may protect high-risk patients against heart attacks
People on statins but still at risk for heart attack and stroke saw a benefit. Cholesterol-lowering drugs may one day gain a sidekick in the battle against heart disease. Taking a potent drug derived from fish oil along with a statin lowers the risk of heart attack and stroke in some high-risk people, researchers report. A clinical trial called REDUCE-IT tested the approach in more than 8,000 participants who either had cardiovascular disease or were at high risk for it. These people were already on statins to lower their cholesterol, and also had high levels of fats called triglycerides in their blood. Elevated triglycerides can increase one’s risk of heart attack and stroke. People took either a two-gram pill of a highly purified omega-3 fatty acid — the oil found in fatty fish — twice daily or a placebo, and were followed up to six years. Of the omega-3 group, 17.2 percent had a fatal or nonfatal heart attack or stroke, compared with 22 percent in the placebo group. Overall, the omega-3 drug, called Vascepa, reduced the risk of heart attack or stroke by 25 percent, researchers announced November 10 at the American Heart Association’s annual scientific sessions in Chicago and in a study published online the same day in the New England Journal of Medicine. The results are “strikingly positive,” says cardiologist Carl Orringer of the University of Miami Miller School of Medicine who was not involved in the study. For people taking statins and working to combat high levels of triglycerides with healthy diet and exercise, the new drug appears to provide additional benefit, he says.

11-10-18 Vitamin D supplements don’t prevent heart disease or cancer
In the largest clinical trial yet, taking a supplement or a placebo made little difference. Taking a vitamin D supplement does not reduce the risk of having a potentially fatal heart attack or stroke or for getting an invasive cancer, according to highly anticipated results of a large clinical trial. The VITAL trial found no significant difference in cancer or heart health risk between people taking 2,000 international units, or IU, of vitamin D a day and those who took a placebo, researchers reported November 10 at the American Heart Association’s annual scientific sessions. The results dim the luster of a vitamin once hailed as a drug that could strengthen bones and prevent conditions from obesity and diabetes to heart and autoimmune diseases. “What this does show is that the general population does not need to be taking vitamin D for cardiovascular health or cancer health,” says Erin Michos, a preventive cardiologist at Johns Hopkins School of Medicine who was not involved in the study. “This is the most definitive trial to date on this issue.” Researchers have known for a long time that people with low levels of vitamin D in their blood are at higher risk for heart attacks, strokes, heart failure and an irregular heartbeat known as atrial fibrillation. But VITAL, a Phase III clinical trial, is the largest randomized trial to specifically test whether boosting levels of the vitamin can prevent cardiovascular disease.

11-9-18 Phthalates and language delays
Prenatal exposure to a type of chemical found in floor tiles, food packaging, shampoos, and cosmetics could cause language delays in young children, new research suggests. Scientists have long been concerned that phthalates, which make plastics more flexible and long-lasting, can affect the development of children’s brains. The new study—a collaboration between teams in Sweden and the U.S.—looked specifically at their impact on early speech development, reports The Philadelphia Inquirer. Researchers tested urine samples from about 1,365 pregnant women, all in their first trimester, for phthalates. When the women’s children were between 30 and 37 months old, the researchers asked the mothers how many words their offspring used. They found that the children of women who had higher phthalate levels during pregnancy were more likely to suffer from a language delay, knowing fewer than 50 words. One of the study’s authors, Shanna Swan from the Icahn School of Medicine in New York, advises pregnant women to try to reduce their exposure to phthalates by using scent-free personal-care products and phthalate-free nail polish. But she acknowledges that the chemicals are “hard to avoid,” because they are “hidden in many household products, like vinyl floor covering and upholstery.”

11-9-18 In My Father’s House: A New View of How Crime Runs in the Family
Every town seems to have a family like the Bogles—and maybe that should tell us something, said Alice Lloyd in The Weekly Standard. In Fox Butterfield’s perversely pleasurable new book about the sources of criminal behavior, a Texas-born con artist named Elvie Bogle and her sons and grandsons provide “almost abusively vivid” evidence that certain families breed lawbreakers. Butterfield eventually identified 60 convicts in the Bogle family tree, and he gained the confidence of enough of them to be able to share their favorite tales about swindles, robberies, car thefts, and kidnappings—even a heist of salmon from a fish hatchery. The Bogles aren’t simply colorful outliers, though. Butterfield cites studies indicating that 5 percent of all families account for perhaps half of all crimes, and 10 percent for two-thirds. But identifying a cycle of criminality is one thing; “the questions get thicker when it comes to how to stop it,” said Eric Spitznagel in the New York Post. Should criminals have their children taken away, as has been done in Italy? Or what about simply providing incentives to released prisoners to encourage them to move away from home and attempt fresh starts elsewhere? Though Butterfield doesn’t have all the answers, “he has found a seam in an uncrackable problem,” said Philip Martin in the Little Rock, Ark., Democrat-Gazette. And he ends with “a note of uplift”: the story of a granddaughter of Rooster’s who, thanks in part to parents who shielded her from contact with her extended family, became not long ago the first Bogle to earn a college degree.

11-9-18 The perils of gloomy weather
Cold, cloudy, and gray weather doesn’t just make people miserable—it can also increase their risk of suffering a heart attack. Researchers looked at weather records and the medical data of 274,000 patients in Sweden between 1998 and 2013, reports The Guardian (U.K.), and found an increased incidence of heart attacks during periods with lower air temperature and air pressure, higher wind velocity, and fewer sunshine hours. The most pronounced link was with temperature; heart attack rates increased noticeably when the mercury dropped below 37 to 39 degrees Fahrenheit. The scientists suggested several possible factors: arteries narrowing because of the cold, people exercising less and eating more unhealthy foods on gloomy days, and the seasonal spread of infections. “We are very interested in the triggers of heart attacks,” says study leader David Erlinge, from Lund University. “If you know those triggers, you may be able to protect yourself.”

11-9-18 Ebola warning
An outbreak of the deadly Ebola virus in war-torn Congo has become so serious that health officials might not be able to contain it, the U.S. Centers for Disease Control and Prevention warned this week. Since the hemorrhagic disease was first identified in 1976, health workers have successfully contained all outbreaks—most of them in remote areas—before they could spread too widely. The current outbreak in Congo’s North Kivu province is entering its fourth month, with some 300 cases, including 186 deaths. It could soon become endemic in the province, home to 6 million people, making it easier for the deadly virus to spread through travel and trade, the CDC said. North Kivu is an active war zone, complicating the work of Ebola response teams.

11-9-18 Taking your coffee black
Taking your coffee black, after a new study found that people who shun milk and sugar in their java are more likely to be psychopaths. Researchers found a “robust relation between increased enjoyment of bitter foods and heightened sadistic proclivities.”

11-9-18 Vegetarians
Vegetarians, who report lower self-respect and derive less pleasure from life than omnivores, a new study found. The primary problem, said researcher Dr. John Nezlek, is that “vegetarians may be excluded from social events or made to feel odd or different.”

11-9-18 Ancient DNA suggests people settled South America in at least 3 waves
New genetic analyses are filling in the picture of who the earliest Americans were. DNA from a 9,000-year-old baby tooth from Alaska, the oldest natural mummy in North America and remains of ancient Brazilians is helping researchers trace the steps of ancient people as they settled the Americas. Two new studies give a more detailed and complicated picture of the peopling of the Americas than ever before presented. People from North America moved into South America in at least three migration waves, researchers report online November 8 in Cell. The first migrants, who reached South America by at least 11,000 years ago, were genetically related to a 12,600-year-old toddler from Montana known as Anzick-1 (SN: 3/22/14, p. 6). The child’s skeleton was found with artifacts from the Clovis people, who researchers used to think were the first people in the Americas, although that idea has fallen out of favor. Scientists also previously thought these were the only ancient migrants to South America. But DNA analysis of samples from 49 ancient people suggests a second wave of settlers replaced the Clovis group in South America about 9,000 years ago. And a third group related to ancient people from California’s Channel Islands spread over the Central Andes about 4,200 years ago, geneticist Nathan Nakatsuka of Harvard University and colleagues found. People who settled the Americas were also much more genetically diverse than previously thought. At least one group of ancient Brazilians shared DNA with modern indigenous Australians, a different group of researchers reports online November 8 in Science.

11-9-18 Sabre-toothed cats shared their food with injured pride members
Fearsome sabre-toothed cats may have had a tender side. The prehistoric predators risked damaging their powerful jaws and teeth during hunts, but a study of their fossils suggests injured individuals could then rely on their peers for food. Urban Los Angeles is home to the tar pits at Rancho La Brea. For most of the last 40,000 years, sticky tar has trapped and preserved animals wandering across this landscape, providing a window into the animals of the Pleistocene period. What’s really special about these tar pits, says Larisa DeSantis at Vanderbilt University in Tennessee, is that it particularly preserved top predators. Because apex predators tend to be few in number, fossils of animals that top the food chain are usually very rare. But the tar pits acted almost like fly paper for predators: they were attracted by the distress calls of trapped herbivores and then got caught themselves. So many sabre-toothed cat (Smilodon) fossils have been pulled from the tar that DeSantis and her colleague, Christopher Shaw at the George C. Page Museum of La Brea Discoveries in Los Angeles, have been able to begin to understand how these animals lived. The two researchers compared 21 Smilodon skulls that showed sign of jaw injuries with 135 skulls that looked uninjured. They found that the pattern of pits and scratches on teeth in the uninjured jaws looks like that seen on the teeth of living lions. The pattern on injured jaws was more like that seen on the teeth of living cheetahs. That tells us something about the prehistoric cats’ diets, says DeSantis. “Lions are generalised feeders, they eat flesh and bone,” she says. “But cheetahs tend to avoid bone.”

11-8-18 Indigenous peoples in the Amazon and Australia share some ancestry
The genomes of 15 ancient Americans, including six that are more than 10,000 years old, have been sequenced. The results reveal how people first spread through the Americas – and also throw up a major mystery. The big picture is clear. Around 25,000 years ago during the last ice age, the ancestors of modern native Americans moved across the Beringian land bridge into what is now Alaska. They remained there for millennia because the way south was blocked by ice. Once a path opened up, groups of hunter-gatherers moved south very quickly. “Once they are south of the ice, they are meeting with these amazing conditions, with lots of resources and no competition,” says Víctor Moreno-Mayar of the University of Copenhagen in Denmark, a member of the large international team that did the work. Southern native Americans split from northern ones around 16,000 years ago, the results suggest, and reached South America not long afterwards. The genomes reveal many more details about this process. For instance, it appears some previously unknown group split away from northern native Americans at some point and then moved into South America around 8000 years ago, long after the initial migration. But the study also adds to a big mystery: some groups in the Amazon are somewhat more closely related to the Australasians of Australia and Papua New Guinea than other native Americans are. The genomes show this “Australasian signal” is more than 10,000 years old. So where did it come from?

11-8-18 How a life-threatening allergic reaction can happen so fast
In mice, specialized cells monitor for allergens and pass intel to response-triggering immune cells. Within minutes of biting into peanut-tainted food, people with a peanut allergy may find their pulse quickening, blood pressure plummeting and throat closing up. They’re experiencing a rapid and sometimes fatal allergic reaction called anaphylaxis. New research in mice explains how even a small amount of an allergen can quickly trigger such a strong, full-body reaction. The culprit is a type of cell that probes the bloodstream for allergens and then broadcasts the invaders’ presence to anaphylaxis-inducing immune cells, researchers report in the Nov. 9 Science. When these immune cells, called mast cells, detect an allergen that they’re sensitized to, they flood the body with inflammatory proteins that set off an allergic reaction. But how mast cells, which line the space surrounding blood vessels, are so efficient at detecting allergens floating along in the blood has been a long-standing question, says Stephen Galli, an immunologist at Stanford University who wasn’t involved in the research. In the case of a snakebite, fangs can pierce blood vessels and make it easy for venom, which also activates mast cells, to reach the cells. But with a food allergy, the vessels are usually intact. In the study, researchers systematically lowered the levels of different types of immune cells in mice to see how the animals’ response to egg allergens changed.

11-8-18 The cause of half of all developmental disorders is a genetic mystery
“If we have more children, will they also have the disorder?” That’s the question parents ask after discovering their child has a developmental disorder – and it looks as though providing an answer is going to be even more complex than we thought. About 1 in 100 children are born with unexplained deformities of the body, learning or behavioural difficulties – including autism – and other health problems such as heart disorders. The causes are thought to be genetic even though neither parent is affected. How can this be? Last year, the Deciphering Developmental Disorders project, based at the Wellcome Sanger Institute in the UK, reported that nearly half of the developmental disorders in 4000 children in Europe were due to a new mutation occurring in the sperm or eggs of one parent. As for the rest, the leading idea was that they were due to rare recessive mutations – mutations that only have an effect if both copies of a gene have the mutation. But in a study of 6000 children in Europe with developmental disorders, the project has now shown that only 4 per cent of developmental disorders are due to recessive mutations in the protein-coding parts of genes. In other words, around half the cases remain unexplained. “That was a surprise,” says team member Hilary Martin. The most likely explanation, she thinks, is that the effect of many rare genetic variants depends on what other variants an individual inherits. A parent might carry a mutation without any ill-effects, but when combined with gene variants from the other parent the same mutation could have very serious effects.

11-8-18 The number of calories you burn while resting depends on the time of day
The body’s resting metabolism is governed by circadian rhythms. Timing is everything. Even how many calories a person burns while at rest depends on the hour. People burn about 129 more calories when resting in the afternoon and evening than in the early morning. But morning is better for burning carbohydrates, while fats are more likely to be burned in the evening, researchers report November 8 in Current Biology. The findings add to evidence that when people eat and sleep may be as important as what they eat for maintaining proper health (SN: 10/31/15, p. 10). Calories burned at rest fuel breathing, circulation and brain activity, while also helping to maintain body temperature. Researchers previously had conflicting evidence about whether a resting body burns calories at a fairly constant rate, or one that rises and falls in a daily — or circadian — rhythm. The study shows that a body’s resting metabolism is governed by circadian clocks, neuroscientist Jeanne Duffy of Brigham and Women’s Hospital in Boston and colleagues report. The study followed seven people kept in windowless rooms for three weeks, without any clues to the time of day. Each night, the seven went to bed four hours later than the previous night. That’s the equivalent of traveling around the world and crossing all time zones within a week. The schedule change allowed the researchers to study the natural body rhythms of each subject without outside influences.

11-8-18 Ancient tribes of Scotland learned to write after contact with Romans
Scottish fisherman pulled up a rare catch near Aberdeen earlier this year: a large stone etched with geometric markings. It was a Pictish symbol stone, with a meaning and age as enigmatic as the people who made it. Now it seems that the Picts began carving their symbols much earlier than we had thought, possibly influenced by the Romans – which bolsters the idea that the symbols are remnants of an ancient writing system. The Picts were a coalition of tribal kingdoms inhabiting the far north of what is now Scotland, between about 1700 and 1100 years ago. Their first mention in the written record is from the Roman writer Eumenius, who coined the name Picti – literally “painted people” – in AD 297, likely referring to their tattoos. But while the Romans wrote about the Picts, as far as we know the Picts themselves left no surviving written records. One thing they did leave, though, is about 200 stone slabs adorned with symbols of varying complexity. There are carved bulls, eagles and fish, as well as abstract and intricate geometric patterns. Among the symbols are around 30 that appear often, almost always in pairs. Because the stone slabs were found in locations that seem to have been important to the Picts, these paired symbols are thought to be some sort of naming system for Pictish families. There is no agreement on their precise meaning – but there is a growing consensus that the symbols are actually some sort of non-alphabetic script, similar to Egyptian hieroglyphs. Dating the carvings could help unravel their meaning, but doing so is not easy – carving a stone leaves no convenient organic marker for carbon dating.

11-7-18 Blood test can spot DNA from eight different types of cancer
A simple blood test can detect eight different types of cancer. It does this by detecting the various sizes of tumour DNA fragments that flow through the body. At the moment, most cancer screening tools are limited to specific areas of the body – for example, mammograms for spotting breast cancer and faecal tests for detecting bowel cancer. Whole-body MRI and CT scans can identify tumours throughout the body, but only once they have grown large enough to see. As a result, many research groups are working on developing blood tests that can detect multiple different cancer types while they are still in early, treatable stages. A popular approach is to genetically sequence blood to see if it contains any tell-tale tumour DNA markers. But this is like looking for needles in a haystack because of the large volume of non-cancerous DNA that also circulates in the blood. Now, Florent Mouliere at Cambridge University and his colleagues have devised a different approach that doesn’t require time-consuming genetic sequencing and is potentially more accurate. By looking for characteristic tumour DNA fragment sizes in blood samples, the researchers were able to detect 94 per cent of breast, bowel, ovary, skin, and bile duct cancers in 68 cancer patients, with a false positive rate of 2.5 per cent, i.e., the rate at which it identified a cancer that wasn’t really there. They were also able to identify 65 per cent of pancreas, kidney, and brain cancers in another 57 patients.

11-7-18 World’s first figurative art is of an unknown animal in Borneo
At first glance you might miss it. But a faint drawing of an unknown animal on a cave wall in a remote Borneo jungle is the oldest known figurative art. The painting was made at least 40,000 years ago, predating famous depictions of animals found on European caves and shaking up our understanding of the origins of art – a key innovation in human history. The limestone caves of the remote East Kalimantan province of Borneo are adorned with thousands of images in three distinct styles: reddish-orange hand stencils and paintings of animals, purple hand stencils with intricate designs as well as human figures, and complex black depictions of humans, boats and geometric patterns. But the dates when these painting were created were a mystery. “The art was discovered in the 1990s. We wanted to find out exactly how old it was,” says Maxime Aubert of Griffiths University in Queensland, Australia. So he and his colleagues analysed the calcite layers covering the paintings. This crystalline material is deposited by dripping water and analysis of the uranium it contains gives a date for when the art beneath was created. On a panel of depicting large reddish-orange wild-cattle, the researchers discovered that a faint animal had been drawn between 40,000 and 52,000 years ago. This makes it the oldest known figurative art and builds on the 2014 discovery of a hand stencil dating back at least 35,700 years on the neighbouring Indonesian island of Sulawesi. “It was quite amazing,” says Aubert. The ability to depict real-life objects seems to have developed tens of thousands of years after humans first started to draw. The oldest drawing in the world is a 73,000 year-old crosshatch found in a South African cave. In Europe, the oldest art is also an abstract symbol of red lines and a hand stencil, made by Neanderthals around 65,000 years ago. But these abstract designs are simpler than representational art, which makes the Borneo discovery particularly significant. “Figurative art is a more complex thing to do,” says Aubert.

11-7-18 Marijuana may change the decision-making part of teen brains
A new rat study hints at damage during adolescence. Marijuana use during teenage years may change the brain in key decision-making areas, a study in rats suggests. “Adolescence is a dangerous time to be insulting the brain, particularly with drugs of abuse,” study coauthor Eliza Jacobs-Brichford said November 7 at the annual meeting of the Society for Neuroscience. Jacobs-Brichford and colleagues gave adolescent male and female rats a marijuana-like compound. Afterward, the researchers found changes in parts of the brain involved in making decisions. Normally, many of the nerve cells there are surrounded by rigid structures called perineuronal nets, sturdy webs that help stabilize connections between nerve cells. But in male rats that had been exposed to the marijuana-like compound in adolescence, fewer of these nerve cells, which help put the brakes on other cells’ activity, were covered by nets. Drug exposure didn’t seem to affect the nets in female rats. “Males look more susceptible to these drugs,” said Jacobs-Brichford, a behavioral neuroscientist at the University of Illinois at Chicago.

11-7-18 There’s a dark side to self-control. Here’s why you should loosen up
Willpower is the secret of success – or so we've been told. But too much can be bad for the body and mind. The trick is to know when to give in to temptation. THE Cookie Monster in Sesame Street isn’t known for his self-restraint, but in 2013 the swivel-eyed biscuit fiend experienced a remarkable transformation. Over a series of episodes, he learned to curb his cravings and avoid eating every cookie he saw in an attempt to gain entry to the Cookie Connoisseurs Club. “Me want it (but me wait)” is how Cookie Monster described his dilemma in a catchy musical number. Parents of young viewers may have sensed this storyline had a purpose. It was an attempt to tap into the latest research on self-control, which has been linked to many aspects of success in life. Some argue that it is as important as IQ. Besides inspiring various educational initiatives – including the 44th season of Sesame Street – these finding have spawned numerous media articles and self-help books. “We are surrounded by messages that more self-control is better and that there basically could not be enough self-control,” says Liad Uziel at Bar-Ilan University in Israel. But is it time to question some of these assumptions? Uziel believes so. He and others have discovered that self-control is a double-edged sword. There is no doubt it has benefits, but too much of it can leave you open to exploitation and undermine both your physical and mental well-being. This presents something of a dilemma for the latest educational reforms – and indeed for anyone on the road to self-improvement. Fortunately, the findings also hold lessons for us all about when to wield our rod of iron and when it might be better to cut ourselves some slack.

11-7-18 Your gut is full of neurons and they are replaced every 2 weeks
THE neurons that make up the “brain” in your gut are almost entirely replaced every two weeks, a study in mice suggests. What’s more, an imbalance in the gut’s ability to repopulate itself with new neurons and clear out the dead ones could lead to Parkinson’s disease. Subhash Kulkarni at Johns Hopkins University in Maryland and his colleagues found that neurons in the gut lining of mice are constantly dying at a high rate. These cells are part of the enteric nervous system, the body’s “second brain”. A mouse loses nearly a third of its gut neurons every seven days. But the dead neurons don’t build up, so something must be clearing out the debris. In both the large and small intestine, Kulkarni’s team found neurons being engulfed by macrophages, a kind of immune cell that eats bacteria and viruses. Kulkarni and his team realised that the gut must produce new cells to replace the neurons that have died and been removed. They discovered that the gut has stem cells that proliferate extremely quickly. After two weeks, 88 per cent of the neurons situated between the two layers of muscles in the mouse small intestine were newly formed. In other words, there is a large amount of cellular turnover, but the number of neurons remains the same, says Kulkarni. He presented the study this week at the Society for Neuroscience annual meeting in San Diego. Recent studies have found that the build-up of a protein called alpha-synuclein in the gut may stifle nerve signals in the brains of people with Parkinson’s, a degenerative disease marked by tremors and stiffness (see “We can tell whether pandas are mating successfully by their bleats”). Kulkarni suspects that alpha-synuclein build-up is a consequence of neuron turnover.

11-7-18 A new drug may boost dwindling treatment options for gonorrhea
In a clinical trial, zoliflodacin was effective against the sexually transmitted disease. Gonorrhea is a wily foe. But doctors may soon have another drug to fight the sexually transmitted infection that’s become resistant to nearly every antibiotic thrown its way. In clinical trials, a new antibiotic was effective at stopping the bacteria that causes the disease. A single oral dose of the drug, called zoliflodacin, cured 96 percent of people who had gonorrhea infections in the urinary and genital organs, researchers report in the Nov. 8 New England Journal of Medicine. In comparison, 100 percent of patients given ceftriaxone — the remaining antibiotic that’s effective against the disease in the United States — were successfully treated. Caused by Neisseria gonorrhoeae, gonorrhea can be passed from an infected person to a sexual partner or from an infected mother to her baby at birth. The consequences of the infection are especially severe for women, who can develop pelvic inflammatory disease and become infertile (SN: 6/10/00, p. 376), and for babies, who can lose their sight. The United States had more than half a million new gonorrhea cases reported in 2017, up about 75 percent from the historical low point in 2009. Worldwide, an estimated 78 million new gonorrhea infections occur each year. In the United States, doctors treat an infection with a combination of ceftriaxone and another antibiotic called azithromycin. But bacterial strains resistant to ceftriaxone have cropped up in other countries, raising concerns of untreatable gonorrhea.

11-7-18 Like Europe, Borneo hosted Stone Age cave artists
Animal figures and hand stencils are as old and complex as rock art found in Spain. Discoveries on the island of Borneo illustrate that cave art emerged in Southeast Asia as early as in Western Europe, and with comparable complexity, researchers say. A limestone cave in eastern Borneo features a reddish-orange painting of a horned animal, possibly a type of wild cattle that may have been found on the island at the time. The painting dates to at least 40,000 years ago, concludes a team led by archaeologist Maxime Aubert of Griffith University in Southport, Australia. This creature represents the oldest known example of a painted figure anywhere in the world, the scientists report online November 7 in Nature. The same cave walls contain two hand outlines framed in reddish orange pigment that were made at least 37,200 years ago and a similar hand stencil with a maximum age of 51,800 years. Three nearby caves display instances of a second rock art style that appeared around 20,000 years ago, the investigators say. Examples include purple-hued, humanlike figures and hand stencils, some decorated with lines or dots. Painted lines link some hand stencils to others.

11-7-18 'Oldest animal painting' discovered in Borneo
The earliest known painting of an animal has been identified in a cave on the island of Borneo. The artwork, which is at least 40,000 years old, is thought to be the oldest example of figurative painting - where real objects are depicted rather than abstract shapes. The researchers aren't certain what animal it represents, but their hunch is that it's a banteng, a type of wild cow that lives in the area today. The work appears in Nature journal. The painting was found in a system of caves in the remote and rugged mountains of East Kalimantan, an Indonesian province on Borneo. The caves contain thousands of other prehistoric paintings, drawings and other imagery, including hand stencils, animals, abstract signs and symbols."This is a very large area with many paintings and many caves - it's a major archaeological discovery," said Prof Francesco d'Errico, an authority on prehistoric art from the University of Bordeaux, France, who was not involved in the latest research. Co-author Maxime Aubert, from Griffith University in Australia, commented: "The oldest cave art image we dated is a large painting of an unidentified animal, probably a species of wild cattle still found in the jungles of Borneo - this has a minimum age of around 40,000 years and is now the earliest known figurative artwork." The animal appears to have a spear shaft stuck in its flank and is one of a series of similar red-orange coloured paintings, which were made with iron-oxide pigment. These paintings, which include other depictions of animals along with hand stencils, appear to represent the oldest phase of art in the cave. The animals, said Dr Aubert, are "painted in the same style with a large body and small legs".

11-7-18 Neanderthals may have breathed deeply and breastfed infants for years
WE KNOW a lot about Neanderthals, but gaps in our understanding remain. Now insights have been shed on how they fed their infants, and it has also been revealed how the ancient humans got enough oxygen to power their bulkier bodies. Tanya Smith at Griffith University in Australia and her colleagues examined a pair of 250,000-year-old teeth from France. This revealed that Neanderthal children were exclusively breastfed for nine months, and fully weaned at around 2.5 years of age (Science Advances, doi.org/cwmz). The first tooth, which probably formed soon after birth, had high levels of barium – a sign of milk ingestion – in layers from before 9 months of age, and moderate barium levels up to about 2.5 years of age. The second tooth, which was likely to have formed at around the age of 3, had no elevated barium. The findings suggest that Neanderthals had similar weaning patterns to modern humans in hunter-gatherer communities. In a separate study, Asier Gómez-Olivencia at the University of the Basque Country in Spain and his colleagues analysed a 60,000-year-old adult, male Neanderthal specimen. They generated a 3D reconstruction of the ribcage, finding that it was the same size as ours. This is a surprise because Neanderthals had stockier bodies than us, suggesting they needed more oxygen, so probably had larger lungs. But the 3D reconstruction reveals that the Neanderthal ribcage was instead a slightly different shape, with a wider bottom (Nature Communications, doi.org/cwmx). Gómez-Olivencia and his colleagues think this could mean Neanderthals had a larger diaphragm, the sheet of muscle that contracts when we breathe. This may have enabled them to inhale more strongly, taking in more air with each breath.

11-6-18 More than 60 prescription drugs are getting into river foodchains
Over 60 common pharmaceuticals have been found in river-dwelling wildlife in Australia, highlighting the need for better wastewater treatment strategies. When we take a drug, a portion sometimes passes through us intact and goes down the toilet. But as most medications are not removed during sewage treatment, they often end up in waterways. To find out if pharmaceutical waste then finds its way into aquatic creatures, Erinn Richmond at Monash University in Melbourne, Australia and her colleagues sampled flies, beetles, spiders and other insects from six waterways in the greater Melbourne region. The sites varied from a treated sewage run-off stream to a river in a national park. The researchers detected 69 medications in the insects, including antidepressants, painkillers, antibiotics, and blood pressure-lowering agents. The highest levels were found in insects near wastewater plants, but low levels were also detected in those from more pristine areas. River-borne pharmaceuticals most likely accumulate in flies and beetles while they are underwater larvae, then transfer to spiders that feed on them after they emerge as adults, says Richmond. Other predators like fish, platypuses, birds, bats and frogs may also become cross-contaminated, she says. (Webmaster's comment: And with 7.7 billion people dumping these pharmaceuticals into our water supply this problem is HUGE!)

11-6-18 Gene therapy injection into spinal cord halts ALS in adult mice
A new delivery method could take us a step closer to a gene therapy for amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder in which nerve cells progressively stop working throughout the spinal cord and the brain. Animal studies have already suggested that ALS can be prevented by replacing the mutated genes that cause some forms of the condition with normal versions. But delivering genes to nerve cells in the spine is a challenge. The new method involves injecting corrected genes beneath the tissues that protect the spinal cord. The technique has been shown to correct 89 per cent of genes associated with an inherited form of ALS. Ten per cent of ALS patients have an inherited version of the disease, and 20 per cent of those people have a mutation in a gene called SOD1 that causes their ALS. There is currently no effective treatment for this familial form of ALS or the more common sporadic ALS, both of which have a median survival of 3 to 5 years after the onset of symptoms. Martin Marsala and Mariana Bravo Hernandez at the University of California San Diego and their colleagues inserted a compound that silences the SOD1 gene into a virus. They then injected the virus into adult mice with an inherited ALS-like condition just above their spinal cords. “We’re injecting it beneath the membranes that protect the spinal cord, so there’s no barrier. That’s what allows us to impact all the neurons inside the spinal cord,” says Bravo Hernandez.

11-6-18 Hormone helps regrow frog legs and may one day lead to a human therapy
Could we one day regrow amputated limbs? We have taken a small step down this road with partial regeneration of the hind legs of frogs. Several kinds of animals can regenerate damaged body parts to some extent, including flatworms, fish and some amphibians. With just a few exceptions mammals seem to have lost this ability in their evolutionary past but there’s hope it could be reawakened with the right chemical nudges. A species of African frog has relatively weak limb regenerating powers. If they lose a leg they normally regrow a thin spike of rubbery cartilage. But now Michael Levin at Tufts University, Massachusetts, and his colleagues have coaxed the animals into re-growing a wider, paddle-like structure complete with bones, nerves and blood vessels – although it lacked a foot. The team achieved their results with progesterone, which is best known as a female sex hormone, but which also plays a role in wound repair. It was delivered with a bioreactor, a small box containing progesterone-loaded gel that was sewn over the wound straight after amputation.

11-6-18 Loneliness is bad for brains
Solitary confinement shrinks nerve cells in mice, study finds. Mice yanked out of their community and held in solitary isolation show signs of brain damage. After a month of being alone, the mice had smaller nerve cells in certain parts of the brain. Other brain changes followed, scientists reported at a news briefing November 4 at the annual meeting of the Society for Neuroscience. It’s not known whether similar damage happens in the brains of isolated humans. If so, the results have implications for the health of people who spend much of their time alone, including the estimated tens of thousands of inmates in solitary confinement in the United States and elderly people in institutionalized care facilities. The new results, along with other recent brain studies, clearly show that for social species, isolation is damaging, says neurobiologist Huda Akil of the University of Michigan in Ann Arbor. “There is no question that this is changing the basic architecture of the brain,” Akil says.

11-6-18 A lack of sleep can induce anxiety
Brain activity is altered in people spending the night awake. A sleepless night can leave the brain spinning with anxiety the next day. In healthy adults, overnight sleep deprivation triggered anxiety the next morning, along with altered brain activity patterns, scientists reported November 4 at the annual meeting of the Society for Neuroscience. People with anxiety disorders often have trouble sleeping. The new results uncover the reverse effect — that poor sleep can induce anxiety. The study shows that “this is a two-way interaction,” says Clifford Saper, a sleep researcher at Harvard Medical School and Beth Israel Deaconess Medical Center in Boston who wasn’t involved in the study. “The sleep loss makes the anxiety worse, which in turn makes it harder to sleep.” Sleep researchers Eti Ben Simon and Matthew Walker, both of the University of California, Berkeley, studied the anxiety levels of 18 healthy people. Following either a night of sleep or a night of staying awake, these people took anxiety tests the next morning. After sleep deprivation, anxiety levels in these healthy people were 30 percent higher than when they had slept. On average, the anxiety scores reached levels seen in people with anxiety disorders, Ben Simon said November 5 in a news briefing.

11-6-18 ‘End of the Megafauna’ examines why so many giant Ice Age animals went extinct
New book's colorful illustrations also offer perspective of just how large these creatures were. Today’s land animals are a bunch of runts compared with creatures from the not-too-distant past. Beasts as big as elephants, gorillas and bears were once much more common around the world. Then, seemingly suddenly, hundreds of big species, including the woolly mammoth, the giant ground sloth and a lizard weighing as much as half a ton, disappeared. In End of the Megafauna, paleomammalogist Ross MacPhee makes one thing clear: The science on what caused the extinctions of these megafauna — animals larger than 44 kilograms, or about 100 pounds — is far from settled. MacPhee dissects the evidence behind two main ideas: that as humans moved into new parts of the world over the last 50,000 years, people hunted the critters into oblivion, or that changes in climate left the animals too vulnerable to survive. As MacPhee shows, neither scenario matches all of the available data. Throughout, Peter Schouten’s illustrations, reminiscent of paintings that enliven natural history museums, bring the behemoths back to life. At times, MacPhee slips in too many technical terms. But overall, he offers readers an informative, up-to-date overview of a fascinating period in Earth’s history.

11-5-18 A mashup of yeast and E. coli shows how mitochondria might have evolved
Forcing the two organisms to cooperate hints at origins of cells’ energy factories. Yeast intentionally stuffed with bacteria may teach scientists something about the origins of cells’ powerhouses. Cellular power-generating organelles, called mitochondria, are thought to have once been bacteria captured by archaea, single-celled microbes that are one of the earliest forms of life. Now, almost all eukaryotic cells (cells with a nucleus) contain mitochondria. At first, the bacteria may have lived inside archaea as endosymbionts, independent organisms that cooperate with their hosts. Over time, mitochondria lost many of their genes and eventually became an integral part of the cell. This scenario has support from genetics. But “if you really want to prove something’s true,” says chemical biologist Peter Schultz, researchers should be able to make something similar in the lab. So Schultz, of the Scripps Research Institute in La Jolla, Calif., and his colleagues created a hybrid cell by fusing two popular lab organisms — the baker’s yeast Saccharomyces cerevisiae and a common gut bacteria called E. coli. “It’s a pioneering approach,” says evolutionary biologist Antonio Lazcano of the National Autonomous University of Mexico in Mexico City, who was not involved in the experiments. No one has made such a hybrid organism before. But the work, described October 29 in the Proceedings of the National Academy of Sciences, suggests it may not be so hard to make a free-living organism into an endosymbiont, he says.

11-4-18 Malaysia is ground zero for the next malaria menace
Deforestation brings monkeys and humans close enough to share an age-old disease. Vinita Surukan knew the mosquitoes were trouble. They attacked her in swarms, biting through her clothes as she worked to collect rubber tree sap near her village in Sabah, the northern state of Malaysia. The 30-year-old woman described the situation as nearly unbearable. But she needed the job. There were few alternatives in her village surrounded by fragments of forest reserves and larger swaths of farms, oil palm plantations and rubber tree estates. So she endured until a week of high fever and vomiting forced her to stop. The night of July 23, Surukan was trying to sleep off her fever when the clinic she visited earlier in the day called with results: Her blood was teeming with malaria parasites, about a million in each drop. Her family rushed her to the town hospital where she received intravenous antimalarial drugs before being transferred to a city hospital equipped to treat severe malaria. The drugs cleared most of the parasites, and the lucky woman was smiling by morning. Malaria has terrorized humans for millennia, its fevers carved into our earliest writing on ancient Sumerian clay tablets from Mesopotamia. In 2016, four species of human malaria parasites, which are spread by mosquito from person to person, infected more than 210 million people worldwide, killing almost 450,000. The deadliest species, Plasmodium falciparum, causes most of the infections.

11-3-18 Why men think eating meat makes them manly
How the pressures of masculinity can affect men's diet. We like to think that, as rational humans, we make choices based on objective standards. But behavioral psychology repeatedly demonstrates otherwise. When it comes to race, gender, and class — and even height and hair color — research shows that we make value judgments based on arbitrary assessments. Not surprisingly, the same holds true when it comes to food. A recent study, led by University of Southampton researchers Emma Roe and Paul Hurley, explored the intersection of masculinity and meat eating. Focusing on three groups of men — "'green'-minded men, exercising men, and men who receive emergency food aid" — it found that, according to Roe, while "many men are interested in eating less meat," they have a hard time doing so without "social permission." This was true for all categories. The authors frame this finding in environmental terms. With animal agriculture accounting for 14 percent of greenhouse gas emissions, and with 83 percent of agricultural land dedicated to raising and feeding livestock, they conclude that unraveling "this strong cultural association between men and meat" may be critical to the prospects of global sustainability. Not everyone is buying the men and meat connection. Baylen Linnekin, author of Biting the Hand that Feeds Us, questions what he calls a "masculinity and meat consumption trope." Highlighting studies that seem designed more to generate headlines than advance our knowledge of food choice (including a study that connects veganism to "white masculinity"), Linnekin, who questions Roe and Hurley's methodology, notes that, "I don't know too many eaters who need an attaboy before they feel comfortable exercising their dietary choices openly." He concludes with a simple directive: "Eat whatever the hell you want." Carol Adams, author of The Sexual Politics of Meat, has a different take on the study. "Yes," she writes in an email exchange, "this study reminds us that masculinity is always being constructed by cues from other men. There is homosocial bonding in sharing expectations about what men eat." But she finds it ironic that "meat — supposedly symbolic of strength and virility — is being eaten because men are too afraid to change in front of other men." She hopes to see follow studies look into "how quickly meat eaters become defensive and the attacks they make on vegans" in the first place. Another paper, published in the journal Appetite, examines the compelling link among not only meat and gender, but class status as well. Part of the research the team behind is conducted involved offering participants a "beast burger" presented as either meat-based or vegetarian. The highest demand for the meat option came "from those who rated themselves lower in socioeconomic status." Meat, to the extent that it's associated with power, becomes "substitutable for the status they lack."

11-2-18 Neandertal teeth reveal the earliest known signs of lead exposure
Chemical analyses provide more clues about the environments our ancient relatives lived in. Traces of lead found in the molars of two young Neandertals found in southeast France provide the earliest recorded evidence of lead exposure in hominids. Like tiny time capsules, chemical signatures in the 250,000-year-old chompers chronicle specific times — mostly during the winter months — when the two individuals were exposed to the element as children, researchers report online October 31 in Science Advances. “There are clocks inside our mouths,” says Tanya Smith, a human evolutionary biologist at Griffith University in Brisbane, Australia. By analyzing fossilized teeth, “you get this incredible insight into what [life] was like in the past.” The finding was part of a study that tracked nursing habits of the species and seasonal changes in the environment. Tooth enamel grows in layers, trapping chemicals contained in the water and food that animals, including humans, consume. Neandertal teeth were no different in this regard. Both tooth samples revealed layers with elevated lead levels at multiple points throughout the youngsters’ first years of life. Chemical analysis of thin slices of tooth from one Neandertal, for instance, revealed the first signs of lead exposure starting at about 2.5 months of age, increasing at 9 months and spiking just after turning 2 years old.

11-2-18 Eating less protein may help curb gut bacteria’s growth
The microbes are limited by low nitrogen levels, a study in mice and other mammals suggests. Humans and other animals may have a way to control the growth of gut microbes: Eat less protein. That’s because protein contains nitrogen. And, it turns out, the amount of nitrogen in the diet of mice governed the growth of bacteria in the animals’ large intestine, researchers report October 29 in Nature Microbiology. The finding may help researchers learn how to manipulate the types and amounts of people’s gut bacteria, which can contribute to health and disease. Researchers know that something must limit bacterial growth. “If not, we’d be a few feet deep in E. coli in a couple of days,” says Thomas Schmidt, a microbiologist at the University of Michigan in Ann Arbor not involved in the study. But so far, scientists have had limited success controlling which microbes inhabit the colon. That may be because researchers were looking at the wrong nutrients, Schmidt says. Most, including Schmidt, have usually considered carbon — found in fiber, starch and sugars, for example — to be the most important nutrient microbes eat, he says. The new study suggests that other nutrients such as nitrogen may be as important, or even more important, for controlling bacterial growth.

11-1-18 Fossils hint hominids migrated through a ‘green’ Arabia 300,000 years ago
Ancient animal bones and stone tools are a rare find from the now-harsh environment. Although now characterized by inhospitable deserts, the Arabian Peninsula was a green hot spot for migrating members of the human genus, Homo, at least 300,000 years ago, scientists say. Stone tools found among fossils of antelopes, elephants and other animals at Saudi Arabia’s Ti’s al Ghadah site date to between 300,000 and 500,000 years ago, archaeologist Patrick Roberts and his colleagues say. At that time, the site was located in a grassy, vegetated region that enjoyed regular rains, the researchers report online October 29 in Nature Ecology & Evolution. The new finds support the idea that the Arabian Peninsula had a climate friendly to either Homo sapiens or another Homo species that journeyed out of Africa a few hundred thousand years ago, say Roberts, of the Max Planck Institute for the Science of Human History in Jena, Germany, and his team. Homo sapiens originated in Africa roughly 300,000 years ago. Traditionally, scientists have estimated that human migrations out of Africa began about 60,000 years ago. But recent finds on the Arabian Peninsula, including a human finger fossil from at least 86,000 years ago, have indicated that these dispersals began much earlier (SN: 5/12/18, p. 12).

11-1-18 DNA project to decode 'all complex life' on Earth
A mission to sequence the genome of every known animal, plant, fungus and protozoan - a group of single-celled organisms - is underway. The Earth BioGenome Project (EBP) has been described as a "moonshot for biology". A key aim is to use the information in efforts to conserve threatened species. Scientists say clues about how species adapt to environmental change could be hidden in their DNA code. As part of the project, the Wellcome Sanger Institute, which played a major part in the human genome project, has committed to sequencing the genomes of all 66,000 UK species. Dr Jim Smith, director of science at the Wellcome Trust described the mission as timely, adding that it was "incumbent upon human beings to raise awareness of biodiversity". The aim is to create an entirely new inventory of life on Planet Earth by reading the genetic code of every organism belonging to a vast group known as eukaryotes - essentially, species made up of multiple cells with their DNA bound inside a nucleus. As Prof Harris Lewin from University of California, Davis, who is chair of the project pointed out, "only about 3,300 of the 1.5 million known species have had their genomes sequenced". "The gaps in our knowledge are a lot bigger than what we know," he told BBC News. "So we're not even filling in the pieces of the puzzle; most of the puzzle is empty." The main ambitions of the project are threefold: 1. Fundamental science: The genomes will be an inventory of knowledge about the biology of life on the planet. 2. Conservation: To protect endangered species from threats like climate change, scientists want to understand the genetic code that underlies their adaptations to their environment. 3. Human welfare: Pinpointing the code for "useful traits" could reveal, for example, medicinal properties embedded in an organism's DNA or ways to protect vital crop species from drought and disease.

11-1-18 Health risks increase for babies born to fathers aged 45 or over
Babies whose fathers are 45 years old or over are more likely to be less healthy at birth, according to a study of more than 40 million deliveries. On average children of older fathers were born 20.2 grams lighter, and had a 14 per cent greater risk of low birth weight than infants born to fathers aged 25 to 34. Babies with fathers aged 45 or older also had a 14 per cent higher chance of being admitted to a neonatal intensive care unit, and were 14 per cent more likely to be premature than those born to younger fathers. The figures come from an analysis by researchers at Stanford University in California of 40 million live births that took place in the US between 2007 and 2016. They report the relative risk rather than the absolute risk, meaning it is still only a small number of births that require neonatal intensive care units, for example. The team says the study was important because it offered rare insight into the impact a father’s age can have on a child, where women have for years been encouraged not to put off having babies due to concerns over health and medical complications. They added that while the absolute risks of being an older father remain low, the findings “emphasise the importance” of including data on men when investigating the public health implications of rising parental age.

11-1-18 Virtual reality therapy has real-life benefits for some mental disorders
Cheap, user-friendly hardware could help VR therapy go mainstream. Edwin adjusted his headset and gripped the game controller in both hands. He swallowed hard. The man had good reason to be nervous. He was about to enter a virtual environment tailor-made to get his heart pumping way more than any action-packed video game: a coffee shop full of people. Determined to overcome his persistent fear that other people want to hurt him, Edwin had enrolled in a study of a new virtual reality therapy. The research aimed to help people with paranoia become more comfortable in public places. In this program, described in March in the Lancet Psychiatry, Edwin could visit a store or board a crowded bus. Virtual strangers can be scary, just like real people. Edwin, who had been diagnosed with paranoid schizophrenia, often found simple errands like grocery shopping overwhelming and exhausting. But facing simulated crowds came with perks. At a nearby computer sat clinical psychologist Roos Pot-Kolder of VU University Amsterdam. She could customize the number of avatars and set their friendliness levels in each scene. That way, Edwin could progress at his own pace. During one session, Pot-Kolder coached Edwin to challenge his own paranoid assumptions. If he saw an angry-looking avatar, she asked, “What could be other reasons for looking mad, besides wanting to hurt you?” Edwin offered: The person could be tired or having personal problems. After three months of VR treatment, public outings were easier, said Edwin, who asked that his last name not be used. “I felt more freedom, more relaxed.” He even performed a poem for 500 people at a talent show, which he “would not have dared” before.

11-1-18 Why air travel makes deadly disease pandemics less likely
It’s what keeps microbiologists awake at night: when the next deadly disease breaks out, modern air travel means it will be halfway round the world before we even notice. Or does it? Mass air travel might instead mean some bad outbreaks are less likely to happen, according to an analysis that turns accepted thinking about pandemics on its head. The idea that the world is overdue for an outbreak of a fatal infectious disease – aka “the Big One” – is so widely accepted it has become a sci-fi plot staple, and the target of intense preparedness efforts by governments. The deadliest epidemic in history, the 1918 Spanish flu, killed over 50 million people in a couple of years. But new diseases don’t spring up from nowhere – they evolve from related strains of viruses or bacteria, point out Robin Thompson of the University of Oxford and colleagues. The new microbe may differ from the old by only a few genetic mutations. That means people previously exposed to the first strain – thanks to air travel – may have some degree of immune resistance to the new deadly strain. So they’d be less likely to catch it, or if they do, to die from it. “It’s like a natural vaccination,” says Thompson. In other words, the continual spreading of germs around the world makes it all the harder for a microbe to evolve in isolation long enough that when it finally breaks out, it wreaks destruction. “We may have been thinking about air travel all wrong,” says Thompson. The team carried out mathematical modelling of factors that affect the spread of a theoretical new and highly virulent microbe in a world with mega-cities and mass air travel. They found that a crucial variable governing the number of cases is the degree of cross-immunity between the pandemic strain and its closest relative.

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