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2019 Science Stats

74 Evolution News Articles
for July 2021
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7-30-21 Two groups of whales evolved massive heads for different reasons
Bowhead and right whales are among the biggest animals alive today, but a new look at how they evolved suggests that these two closely related groups ballooned in size independently, and probably for different reasons. Both are balaenids, a type of baleen whale (a classification that includes the gigantic blue whale), but they aren’t shaped like other baleens. They have stocky bodies and immense heads that can take up a third of their body length, and their mouths are the largest on the planet, equipped with great sheets of hair-like bristles called baleen that they used to filter food from the water. Equations often used to estimate the size of ancient, extinct baleen whales didn’t take into account these peculiar proportions, says Michelangelo Bisconti at the University of Turin in Italy. “Balaenids are fundamental [ecological] players that shape the energy flow in the ocean ecosystems,” says Bisconti, so understanding how they evolved is crucial for unravelling ocean prehistory. Now, he and his colleagues have analysed the proportions of living and fossil balaenid whale species, estimating and mapping changes in size and shape to different time points in their evolutionary history and ancient environmental changes. The team found that right whales (Eubalaena) expanded first – to more than 14 metres long – about 6 million years ago, possibly as a result of a new influx of stable plankton food in their environment. But bowheads (Balaena) grew large a few million years later, possibly as an adaptation to the Arctic habitat, which cooled considerably 3 million years ago. The findings show that some baleen whales may have evolved extreme sizes due to differing environmental pressures, even among closely related species.

7-30-21 A skeleton from Peru vies for the title of oldest known shark attack victim
The 6,000-year-old remains came to light after news of a 3,000-year-old victim in Japan. When news broke that the oldest known case of a person killed by a shark involved a member of Japan’s Jomon culture around 3,000 years ago, two researchers took special notice (SN: 7/23/21). Back in 1976, bioarchaeologist Robert Benfer of the University of Missouri in Columbia and Harvard University anthropological archaeologist Jeffrey Quilter had participated in an excavation of a roughly 17-year-old boy’s skeleton that bore signs of a fatal shark encounter. The boy’s left leg was missing and his right hip and right forearm bones displayed deep bite marks characteristic of those made by sharks, the scientists say. “Successful shark bites usually involve tearing off a limb, often a leg, and ingesting it,” Benfer says. An unsuccessful attempt to ward off a shark presumably resulted in the boy’s arm injuries. Radiocarbon dating indicated that the teen, whose remains were discovered at a Peruvian village site called Paloma, died around 6,000 years ago before being placed in a grave unlike any others in his community, says Benfer, who directed investigations at Paloma in 1976 and in three more field seasons that concluded in 1990. That could make the teen the oldest known shark attack victim. Quilter went on to describe the youth’s shark-related injuries in two paragraphs in a 1989 book, Life and Death at Paloma. But the results were never published in an academic journal. Quilter and Benfer e-mailed the excerpt to the Jomon researchers on July 26. “We were unaware of their claim until now, but are keen to speak to them about it in more detail,” says University of Oxford archaeologist J. Alyssa White, who led the Jomon team. Paloma lies in hills about 3.5 kilometers from Peru’s Pacific coast. Small groups intermittently lived there in round, reed huts between around 7,800 and 4,000 years ago. Paloma’s residents primarily fished, collected or dove for shellfish, and gathered edible plants.

7-30-21 Dinosaur-killing asteroid may have made Earth’s largest ripple marks
Impact created a tsunami that etched massive structures under what’s now Louisiana, study says. The asteroid impact that slew the dinosaurs may have also indirectly sculpted the largest ripple marks ever found on Earth. A series of ridgelike structures more than three stories high and spaced nearly two Eiffel Towers apart appear to be buried about 1,500 meters beneath central Louisiana. The oversized features are megaripples shaped by a massive tsunami generated by the Chicxulub asteroid impact, researchers report in the Sept. 15 Earth and Planetary Science Letters. “It’s just interesting that something that happened 66 million years ago could be so well preserved, buried 5,000 feet down in the sediments of Louisiana,” says geologist Gary Kinsland of the University of Louisiana at Lafayette. Ripple marks are repeating sequences of ridges typically found on sandy beaches or stream bottoms that form as wind or water flows over and moves loose sediment. But ripple marks on the beach are often centimeters in height, while the structures found by Kinsland’s team have an average height of 16 meters and are spaced about 600 meters apart. The marks’ shape, size, orientation and location suggest that they formed after the Chicxulub asteroid crashed into what is today’s Yucatán Peninsula in Mexico, generating a tsunami that washed across the sediments of the Gulf of Mexico and over what is now Louisiana, which was underwater at the time (SN: 11/2/17). Despite the tsunami’s width, no one has ever found ripple marks formed by the wave before. Geologist Kaare Egedahl initially discovered the newly described ripples while searching for coal deposits. Studying at the University of Louisiana at Lafayette at the time, Egedahl had been combing through seismic reflection data – 3-D images of buried rock and soil generated by underground sound waves — provided by the Devon Energy company. Egedahl, now at the oil and gas company Cantium, found the ripples atop a layer of rock thought to have formed from debris shaken up by the Chicxulub asteroid impact. He then shared his finding with Kinsland.

7-29-21 People happily steal from groups even if they are generous one-on-one
Most people play fair in lab tests where they can share or steal small sums of money – yet in real life, unfairness and cheating is common. Now, the apparent contradiction has a new explanation. In lab experiments where people are able to take money from groups of people, they nearly always do, but the same individuals tend to be fair when dealing with just one other person. Economists have long investigated people’s behaviour through simple tests in the lab, such as the two-person “dictator game” in which one person is given a small sum of money and they choose whether to give some of it to their playing partner, who they haven’t met before. Typically, most people give some away, although they get nothing in return, suggesting we have an intrinsic sense of fairness. In real life, though, unfairness is common, ranging from office workers failing to contribute their share of communal snacks through to large-scale financial fraud. We often assume that people who cheat in such ways are a minority, or even that antisocial people are drawn to careers where they can exploit others, says Carlos Alós-Ferrer at the University of Zurich in Switzerland. To investigate, Alós-Ferrer’s team designed a new monetary test called the Big Robber game, where any unfair actions affect larger numbers of people. The researchers asked groups of 32 people to play the dictator game and two other similar games in pairs, and the results were the same as those usually seen, in that most people acted generously. Half the group were also asked if they would like to rob some of the earnings of the other half, which totalled €200, on average. They could take half the amount, a third, a tenth or none of it. The team repeated this process with 640 people in total. Of the 320 individuals given the robbery option, 98 per cent took at least some of the money and 56 per cent took half. To save on costs, the researchers didn’t let everyone actually go home with their chosen amount, but one of the 16 robbers in each group was randomly selected to receive this sum.

7-29-21 Ancient humans in Europe may have stolen food from wild hunting dogs
The earliest humans known to have lived outside Africa shared their environment with hunting dogs – and may even have stolen food from them. For many years, archaeologists have been excavating at a site near Dmanisi in Georgia, where they have found evidence that ancient humans – sometimes put in the species Homo erectus – were present about 1.8 million years ago. The Dmanisi humans provide the earliest fossil evidence yet found of hominins outside Africa. But as ancient humans moved out of Africa, it looks like they encountered prehistoric hunting dogs that were moving into Africa, because the remains of one such dog has now been unearthed at Dmanisi. Saverio Bartolini-Lucenti at the University of Florence, Italy, and his colleagues analysed the remains, which came from a young adult Eurasian hunting dog (Canis (Xenocyon) lycaonoides), an extinct species of hunting dog related to modern African hunting dogs (Lycaon pictus). “Picture an African hunting dog, but stouter with long limbs like an Irish wolfhound, but not so thin,” says Bartolini-Lucenti. This particular animal would have lived about 1.8 million years ago, making it the earliest ever found in Europe. These wild dogs are believed to have originated in Asia, spreading into and across Europe and Africa between about 1.8 and 0.8 million years ago. “Finding it in Dmanisi – which is an important site at the verge, the border of three continents (Asia, Africa and Europe) – is interesting because it is at a timeframe where we didn’t have any occurrences of this form,” says Bartolini-Lucenti. Modern African hunting dogs have adapted to consume their prey very quickly before it can be stolen by larger, stronger predators, such as lions and hyenas. The Eurasian hunting dogs may have interacted with early humans in a similar way, says Bartolini-Lucenti, with the humans scaring off the dogs to steal their prey.

7-29-21 Parents' second-hand marijuana smoke may cause colds in children
Children whose parents smoke or vape cannabis appear to get slightly more respiratory infections, such as colds and flu, than those whose parents just smoke tobacco or don’t smoke at all. The effect may come from children breathing in second-hand marijuana smoke, says Adam Johnson at Wake Forest School of Medicine in North Carolina. “It would make any [respiratory] virus more symptomatic because you have a child’s lungs being exposed to irritants.” Children who breathe in second-hand tobacco smoke are known to have more respiratory illnesses, such as asthma, which has led some countries to ban people from smoking in cars with children present. But the effects of cannabis smoke exposure are less studied, especially as people tend to smoke fewer marijuana cigarettes per day than they do tobacco cigarettes. The new study was done in Colorado, where cannabis was legalised recreationally in 2014. Johnson’s team surveyed 1500 parents of children attending a hospital’s paediatric emergency department for any reason. About 10 per cent of the caregivers smoked or vaped marijuana, while half of those used only marijuana and not tobacco. Parents were asked about various illnesses their children had had in the past year. Children whose parents smoked or vaped marijuana had an average of 1.3 viral respiratory infections in that time, while those who never smoked and those who only smoked tobacco had about 1 per year. There was no significant difference in the number of asthma exacerbations between any of the groups – this may have been because they happened at very low rates, of only about 0.2 such incidents per child on average over the year, says the team. The study doesn’t prove that cannabis smoke caused the infections, as it wasn’t a randomised trial, although the idea is plausible, says Johnson. Relying on parents’ memory of illnesses rather than medical records could also be a limitation.

7-28-21 Second COVID-19 infections are rare and likely mild, research finds
People who catch COVID-19 twice will likely have a milder bout with the disease the second time around, an analysis of U.K. government figures found. The research, conducted by the U.K.'s Office for National Statistics, indicates that viral loads are higher for people who are dealing with their first infection than those who have been reinfected. The more virus that's present in the body tends to lead to a more intense case of COVID-19. The study also found that the rate of reinfection was low overall, and the rate of reinfection with a "strong positive test," which suggests a higher viral load, was even lower. All told, the numbers hint that previous exposure to the coronavirus helps protect people from future run-ins. Read more at Bloomberg and check out the full research U.K. analysis here.

7-29-21 Waves of animals died at an ancient Spanish lake and now we know why
A bunch of large, now-extinct mammals – including European ancestors of giraffes, primitive horses and sabre-toothed deer – died 9 million years ago at a watering hole in Spain. Now, artificial intelligence and painstaking fossil analyses have helped solve the mystery of what happened to them. “I like to jokingly say we are like crime scene investigators: When, how and why did it happen?” says David Martín-Perea at the National Museum of Natural Sciences in Madrid. “The only difference is our ‘crime scenes’ are millions of years old.” Palaeontologists discovered the fossil site, dubbed Batallones-10, in 2007 near Madrid. It took 14 dig sessions to unearth all of the bones buried between 1 and 5.5 metres deep in an area around a quarter the size of a tennis court. So far, the digs have revealed the presence of 15 large mammal species comprising 68 individual animals. Most were plant-eaters. One of the most abundant and well-preserved species was an early European ancestor of giraffes called Decennatherium rex. It was first described after a near-perfect skeleton was found at Batallones-10 in 2013 (see image above). Other animals included now-extinct hipparionine horses, two of which were pregnant, a mastodon, and deer that were relatives of modern-day musk deer, which have fangs instead of horns. Rhinos, giant tortoises, a monitor lizard, sabre-toothed cats, frogs, birds and small mammals were also dug up. Researchers originally suspected the animals died over an extended period from natural causes at a watering hole. Over time, it gradually filled up with mud and dead animals, fossilising their remains. However, in 2020 Martín-Perea and his colleagues used machine learning to seek patterns in the fossils’ precise location coordinates recorded during digs. Results revealed three distinct fossil-forming layers too subtle for humans to discern.

7-29-21 If confirmed, tubes in 890-million-year-old rock may be the oldest animal fossils
If the fossils turn out to be sea sponges, they’d mark a remarkably early start to animal life. Pale, wormlike tubes in 890-million-year old rock may be ancient sea sponges, a new study concludes. If confirmed, that controversial claim would push back the origin of the earliest sponges by about 350 million years and make the tiny squiggles the oldest known fossils of animals, by far. Crucially, these fossils would imply that animals emerged in environmental conditions previously thought unworkable for animal life, geologist Elizabeth Turner reports July 28 in Nature. Early in Earth’s history, the ocean mostly lacked oxygen. It wasn’t until a large pulse of the gas to the atmosphere about 800 million to 540 million years ago, known as the Neoproterozoic Oxidation Event, brought atmospheric oxygen levels to within 10 to 50 percent of modern levels, boosting the amount of oxygen in surface ocean waters (SN: 12/11/19). “But sponges are different from other animals,” says Turner, of Laurentian University in Sudbury, Canada. “Some sponges in the modern world and in the rock record are known to be tolerant of comparatively low oxygen relative to modern ocean levels.” Until now, the earliest, unambiguous fossils of sponges date to about 540 million years ago to the beginning of the Cambrian Period, when an extreme burst in the evolution of animal diversity took place (SN: 7/29/13). Some other animals are known from just a bit earlier, but go too much further back in time and identities become less clear (SN: 3/9/15). Based on genetic data and their relative simplicity, sponges are generally thought to have been the earliest form of animal life. But some scientists aren’t convinced that the newly described tubes are sponge fossils. “Organisms from anywhere on the tree of life can make wiggly, little [branching and rejoining] structures,” says Jonathan Antcliffe, a paleobiologist at the University of Lausanne in Switzerland. The fossils lack features such as mineralized skeletal parts called spicules that would identify the creatures as sponges, he says.

7-28-21 UK conditions are ideal for evolving vaccine-resistant covid variants
BACK in March, an eventual end to the coronavirus pandemic appeared to be in sight. The number of covid-19 cases were plummeting in the UK and the US as vaccination levels rose. It seemed the same might gradually happen in country after country around the world. But then India was hit by a devastating second wave, due largely to a new variant now known as delta. After delta spread to many other countries, case numbers soared once again, including in the UK and US. The question is, will this keep happening? Will more dangerous variants keep evolving, causing fresh waves of infections around the world despite vaccine roll-outs? The answer is almost certainly yes. “Variants will continue to arise, there’s no doubt,” says Ravi Gupta at the University of Cambridge. The SARS-CoV-2 coronavirus mutates relatively slowly compared with some similar viruses. Because of this, there were hopes early in the pandemic that the virus wouldn’t change much and that the pandemic would come to a swift end as people acquired immunity through infection or vaccination. It is now clear that those hopes are forlorn. SARS-CoV-2 has been evolving right from the start. Most mutations either make no difference to the virus’s behaviour or are harmful to the virus and so the viruses carrying them die out. But in March 2020, a mutation called D614G appeared that is now thought to make the virus 50 per cent more infectious. Although it was never given a specific name, it rapidly became the predominant variant. In September, a variant with 23 mutations compared with the original virus was detected in the UK. Alpha, as it is now known, is around 50 per cent more transmissible than D614G and it also spread around the world. Now, we have delta, which is about 50 per cent more transmissible again – and can also evade immunity to some extent, like the beta and gamma variants, two other “variants of concern”.

7-28-21 Thin-air therapy: The unexpected medical benefits of hypoxia
Our organs and cells die without enough oxygen, but in some instances, hypoxia may actually hasten the healing process – and even help people to lose weight. MOUNTAINEERS Ralf Dujmovits and Nancy Hansen are no strangers to thin air, having collectively reached the summits of all eight of the world’s highest mountains. But when they entered the hypoxia chamber at the German Aerospace Center (DLR) in Cologne in May 2018, they were effectively climbing one of the highest peaks of their careers. After a two-week acclimatisation, they spent 16 days breathing air thinner than at Everest base camp – including four days at the equivalent of 7112 metres. This is just shy of the “death zone” over 8000 metres, where the lack of oxygen impairs climbers’ judgement and increases their risk of heart attack and stroke. Time and again, the two mountaineers – and those observing them – questioned whether they should keep going, but they did. If Dujmovits and Hansen could show that humans can tolerate extended periods of low oxygen, known as hypoxia, it would pave the way for an even more ambitious experiment: to test whether, sometimes, it might even be beneficial to starve people of oxygen. This may sound strange. After all, our organs and tissues need oxygen. Indeed, astonishingly low oxygen levels in people with covid-19 have perplexed and panicked doctors (See “Happy hypoxia?”), and treatment guidelines recommend giving extra oxygen. After a heart attack or stroke, people are routinely given oxygen too, to ensure their tissues don’t die. Yet, for all this, surprisingly, there are hints that hearts and spinal cord injuries could heal faster if deprived of oxygen. Could it be that, in some cases at least, we have been breathing too much of a good thing?

7-28-21 Sponge fossils suggest animals already existed 890 million years ago
The origin of animals may have happened 350 million years earlier than thought. Fossils that seem to be sponges, one of the first animals to evolve, have been found in rocks from 890 million years ago. “It seems at first glance that this is a very radical paper,” says Elizabeth Turner at Laurentian University in Sudbury, Canada, who made the discovery. However, she says the fossils she found fit with other evidence. Animals are mostly multicellular organisms whose bodies are made up of distinct tissues, and unlike plants they have to eat food to survive. For years, the earliest-known animal fossils were from the Cambrian Period, which began 541 million years ago. However, in recent years, some fossils from the earlier Ediacaran Period (635 to 541 million years ago) have been identified as animals. There are also 660-million-year-old chemical traces that may be from sponges. Turner studied rocks from north-west Canada that contained the preserved remains of reefs from 890 million years ago, during the Tonian period. These reefs weren’t made by corals, like modern reefs, as these didn’t exist yet. Instead, they were made by photosynthetic bacteria living in shallow seas. The reefs, known as stromatolites, were many kilometres across and rose to heights of hundreds of metres above the seafloor. “These are spectacular reefs,” says Turner. Within the rocks, Turner found the preserved remains of a network of fibres, which branched and joined up in a complex mesh. These are the remains of sponges, she argues, but “not a normal fossil”. The bodies of modern sponges contain a mesh made of a protein called spongin, which forms a soft skeleton. Turner’s work suggests that when ancient sponges died, their soft tissues became mineralised, but the tough spongin didn’t. Eventually, though, it decayed, leaving hollow tubes within the rock that later filled with calcite crystals. These networks of calcite (pictured above) are what Turner then found – and the way the network branched looked just like spongin.

7-28-21 Lost art of the Stone Age: The cave paintings redrawing human history
Newly discovered cave art gives fresh insight into the minds of our ancestors - and upends the idea that a Stone Age cultural explosion was unique to Europe. IN 1879, an 8-year-old girl made a discovery that would rock our understanding of human history. On the walls of Altamira cave in northern Spain, she spotted stunning drawings of bison, painted in vivid red and black. More striking even than the images was their age: they were made thousands of years ago by modern humans’ supposedly primitive ancestors. Today, nearly 400 caves across Europe have been found decorated with hand stencils, mysterious symbols and beautiful images of animals created by these accomplished artists. The discoveries led to the view that artistic talent arose after modern humans arrived in the region some 40,000 years ago, as part of a “cultural explosion” reflecting a flowering of the human mind. But more recent evidence has blown this idea out of the water. For a start, modern humans might not have been the first artists in Europe, as paintings discovered in a Spanish cave in 2018 have revealed. What’s more, a treasure trove of cave paintings emerging in Indonesia has dispelled the idea that Europe was the epicentre of creativity. Indeed, discoveries in Africa indicate that humans were honing their artistic skills long before groups of them migrated to the rest of the world. The real puzzle is why Stone Age cave art seems to be concentrated in a few locations. Could it be hiding elsewhere in plain sight, unnoticed, unrecognised or obscured? Efforts are now under way to track down this missing art, with growing success. The latest discoveries are revealing common themes and hidden codes shared by prehistoric people everywhere. Crack their meaning and we will get an insight into the minds of our ancestors extending back millennia.

7-28-21 Single-celled organism has evolved a natural mechanical computer
A single-celled organism that walks on surfaces using 14 “legs” seems to control these legs with a mechanical computer made of fibres called microtubules. The finding might help explain how many other single-celled organisms engage in extraordinarily sophisticated behaviours despite having no brain or nervous system. “If you can make a computer out of microtubules, you can make the case for looking for them in many other cell types,” says team member Wallace Marshall at the University of California, San Francisco. The study began when Ben Larson, also at UCSF, noticed that the cells he was trying to study kept getting eaten by predators that could scurry along surfaces with an extraordinary, insect-like gait. He knew Marshall was an expert on unusual microbes, so he got in touch. The pair identified the predators as single-celled organisms belonging to the genus Euplotes. These predatory protists are found in both the sea and fresh water. They can swim but also walk on surfaces underwater using around about 14 cirri or legs on their underside (the number varies depending on the species). What has been baffling biologists since the early 20th century is how single-celled creatures with no nerves coordinate the movements of so many legs. So Larson, Wallace and their colleagues decided to study Euplotes in more detail. Larson began by taking videos of 13 Euplotes cells walking on a glass microscope coverslip. Then he painstakingly annotated each cirrus in each video frame so the team could analyse the gait in detail. This revealed that Euplotes have a very unusual gait. Animals with brains, such as millipedes, typically repeat the same pattern of leg movements over and over again. Euplotes‘ legs instead move in lots of different patterns. “It doesn’t have this well-defined, exact sequence of steps that it takes, there’s a lot of variability,” says Larson.

7-27-21 Why it’s still so hard to find treatments for early COVID-19
Scientists are learning surprising lessons about why promising drugs fail in clinical trials. More than a year and a half into the pandemic, researchers are beginning to get a handle on how the coronavirus makes people sick and what to do about it. That includes some valuable lessons about what doesn’t work. Now the trick is to find drugs or therapies that do work, especially for people who aren’t sick enough to go to the hospital. Early treatment may limit transmission of the virus and keep people out of overburdened hospitals. Finding those treatments is proving to be particularly tricky. While the race to create vaccines was astonishingly successful, effective treatments have proved elusive. But they are crucial, especially because the pandemic is far from over. After seemingly gaining ground on the virus in the United States, cases and hospitalizations are again on the rise as the more infectious delta variant sweeps across the country (SN: 7/2/21). The variant is driving a surge of new infections globally, too. “We still have a lot of people who remain unvaccinated” and at risk of getting COVID-19, says Susanna Naggie, an infectious diseases physician at Duke University School of Medicine. “The need for a safe therapy that can be administered at home remains huge.” A few drugs — including the antiviral medication remdesivir, immune system–calming antibody therapies such as baricitinib and tocilizumab and steroids such as dexamethasone — have been literal lifesavers for some of the sickest patients (SN: 4/29/20; SN: 10/30/20; SN: 9/2/20). For instance, real-world data from more than 98,000 people hospitalized with COVID-19 suggest that infusions of remdesivir cut the chance of dying by up to 23 percent, researchers from the drug’s maker Gilead Sciences, Inc., reported at the World Microbe Forum, held online in June. Still, those drugs don’t save everyone, and they are reserved for people who are hospitalized.

7-26-21 Most detailed human genome sequence yet reveals our hidden variation
A new, more complete version of the human genome is already bearing fruit after being released two months ago. It has revealed enormous amounts of genetic variation between people that couldn’t previously be detected – variation that may underlie diseases. “There were variants that were hiding in plain sight,” says Megan Dennis at the University of California, Davis. Other studies suggest that the new genome will finally reveal the functions of seemingly useless “junk DNA”. This DNA is repetitive, which means it has proved difficult to study in detail before now because standard sequencing technology breaks up DNA into very small chunks that are difficult to piece together when the chunks contain repetitive genetic information and so look very similar. “We’ve been blind to it,” says Karen Miga at the University of California, Santa Cruz. Miga is co-leader of the Telomere-to-Telomere consortium, which in May published the most complete sequence of the human genome to date. The new genome filled in the missing 8 per cent of the sequence, most of which is highly repetitive. It also provided a more accurate, less uncertain picture of the remaining 92 per cent of the sequence. Companion papers presented preliminary analyses of the entire genome. Miga and her colleagues have now released another five preprints analysing the new genome. While two are mostly about checking the sequence, the others are new analyses. In one study, Dennis and her colleagues compared the new genome with more than 3000 others, harnessing new information available in the 92 per cent of the genetic sequence that was already known. In particular, they were looking for variants – genetic sites that vary from person to person – and they identified hundreds of thousands of new ones. Using the information in the new genome, it was also possible to improve our understanding of the genetic structure of several hundred genes, says co-author Michael Schatz at Johns Hopkins University in Maryland. “We know there are diseases associated with those genes.”

7-26-21 The new surgical tool inspired by a wasp
Scientists in the Netherlands have mimicked the way parasitoid wasps lay eggs to design a new tool for keyhole surgery. Currently tools used in these procedures are prone to clogging because they use suction. The new device avoids this by using friction. The team, at Delft University of Technology, have a working prototype and hope the tool will be ready within a few years.

7-26-21 Canterbury Cathedral stained glass is among world's oldest
New research indicates that some stained glass windows from Canterbury Cathedral may be among the oldest in the world. The panels, depicting the Ancestors of Christ, have been re-dated using a new, non-destructive technique. The analysis indicates that some of them may date back to the mid-1100s. The windows would therefore have been in place when the Archbishop of Canterbury, Thomas Becket, was killed at the cathedral in 1170. Léonie Seliger, the head of stained glass conservation at the cathedral, and part of the research team, told BBC News that the discovery was historically "hugely significant". "We have hardly anything left of the artistic legacy of that early building [apart from] a few bits of stone carving. But until now, we didn't think we had any stained glass. And it turns out that we do," she said. She said she had been so happy at hearing the news, she had been "ready to dance." Ms Seliger added: "[The stained glass] would have witnessed the murder of Thomas Becket, they would have witnessed Henry II come on his knees begging for forgiveness, they would have witnessed the conflagration of the fire that devoured the cathedral in 1174. And then they would have witnessed all of British history." Thomas Becket was murdered in the cathedral by four knights who believed they were acting on the orders of Henry II, with whom the archbishop had clashed. However, some historians doubt that Henry issued the command to assassinate Becket, and that his words may have been misinterpreted. The re-dated panels are part of the Ancestors of Christ series depicted over one of the cathedral's entrances. It was thought for centuries that they were made by master craftsmen in the 13th century. The art historian Prof Madeline Caviness suggested in the 1980s that some of the panels were earlier than previously believed because they were stylistically different. That suspicion has now been confirmed by a team of researchers from University College London (UCL), who built a device called a "windolyser" to solve the mystery.

7-26-21 3.42-billion-year-old fossil threads may be the oldest known archaea microbes
The structure and chemistry of the filaments hints that they may be ancient cells. Threadlike filaments pressed in rock may be the remnants of archaea that burped methane near hydrothermal vents 3.42 billion years ago. If so, these strands in rock excavated in South Africa around a decade ago, would provide the earliest direct evidence of a methane-based metabolism, researchers report July 14 in Science Advances. Such ancient fossil filaments may contain clues about Earth’s early inhabitants and hint at where to look for extraterrestrial life. Scientists suspect that life on our planet could have arisen in such an environment (SN: 9/24/20). Biologists have deduced that metabolisms based on munching or belching methane evolved early on, but don’t know exactly when, says Barbara Cavalazzi, a geobiologist at University of Bologna in Italy. Previous research has found indirect evidence for methane-cycling microbes in the chemistry of fluid-filled pockets of ancient rocks from around 3.5 billion years ago. But that work didn’t find the actual microbes. With this fossil analysis, “what we find, basically, is evidence of about the same age. But this is a cellular remain — it’s the organism,” Cavalazzi says. The newly identified fossil threads have a carbon-based shell. That shell is different structurally from the preserved interior, suggesting a cell envelope enclosing the cells’ insides, the authors write. And the team found relatively high nickel concentrations in the filaments. The concentrations were similar to levels found in modern methane-makers, suggesting the fossils’ metal may come from nickel-containing enzymes in the microbes. “They can attribute a specific metabolic lifestyle to these early microorganisms,” says Dominic Papineau, a Precambrian biogeochemist at University College London, who was not part of the study and calls it “brilliant work.”

7-24-21 What experts know so far about COVID-19 boosters for immunocompromised people
A third dose might help better protect some, but the CDC is still deciding on official guidance. People with weak immune systems don’t always mount strong defenses against the coronavirus, even after being fully vaccinated. A third COVID-19 vaccine dose might help protect some immunocompromised people, evidence suggests. But for now, there’s not enough data to say how much such a shot might help, experts with the U.S. Centers for Disease Control and Prevention said July 22. As a result, the agency isn’t yet recommending a third dose and says that vaccinated people in this group should keep wearing masks. With global COVID-19 cases on the rise, finding ways to protect millions of immunocompromised people who are at high risk for severe disease is crucial. In the United States, an estimated 2.7 percent of adults, or 6.8 million people, are immunocompromised. Studies suggest that until transmission of the coronavirus is squashed, millions of organ transplant recipients, cancer patients undergoing treatment and others are still susceptible to severe COVID-19, even if they are lucky enough to have access to shots (SN: 2/26/21). Of 45 vaccinated people admitted to 18 U.S. hospitals for COVID-19 from March 11 to May 5, twenty, or 44 percent, were immunocompromised, according to data presented in a July 22 meeting of the CDC’s Advisory Committee on Immunization Practices. A third dose of COVID-19 vaccines can boost coronavirus-fighting antibodies in the blood of some immunocompromised patients, laboratory studies suggest. But it’s still unclear whether specific groups might benefit more than others and how effective extra doses might be at preventing severe COVID-19. The immune system, for instance, has more than antibodies in its arsenal to attack the coronavirus and prevent severe disease (SN: 1/27/21). Studies from the real world would provide a clearer picture for how well additional doses might work, and for which groups.

7-24-21 Las Vegas murder case cracked with smallest ever amount of DNA
The 1989 murder of a 14-year-old girl in Las Vegas has been solved by using what experts say is the smallest-ever amount of human DNA to crack a case. Stephanie Isaacson's murder case had gone cold until new technology made it possible to test what little remained of the suspect's DNA: the equivalent of just 15 human cells. Police on Wednesday said they had identified the suspect by using genome sequencing and public genealogy data. Her alleged killer died in 1995. "I'm glad they found who murdered my daughter," Stephanie's mother wrote in a statement that was read to reporters at Wednesday's news conference. "I never believed the case would be solved." Thirty-two years ago, Stephanie's body was found near the route she normally walked to school in Las Vegas, Nevada. She had been assaulted and strangled. This year, police were able to pick up the case again after a donation from a local resident. They turned over the DNA samples left to Othram, a Texas-based genome-sequencing lab that specialises in cold cases. Typical consumer DNA testing kits collect about 750 to 1,000 nanograms of DNA in a sample. These samples are uploaded to public websites specialising in ancestry or health. But crime scenes may only contain tens to hundreds of nanograms of DNA. And in this case, only 0.12 nanograms - or about 15 cells' worth - were available for testing. Using ancestry databases the researchers were able to identify the suspect's cousin. Eventually they matched the DNA to Darren Roy Marchand. Marchand's DNA from a previous 1986 murder case was still on record, and was used to confirm the match. He was never convicted and died by suicide in 1995. The genomic technology used to solve the case is the same that was used to catch the notorious Golden State Killer in 2018. "This was a huge milestone," Othram chief executive David Mittelman told the BBC.

7-23-21 We thought our eyes turned off when moving quickly, but that's wrong
It has sometimes been assumed that we experience brief periods without vision every time we shift our focus from one point to another – but it turns out this is wrong. Several times each second, we quickly change our line of sight, shifting our focus from one point in a scene to another. These fast, jerky eye movements, or saccades, each last less than 50 milliseconds, and our vision is reduced during that time. Some people have argued that our eyes lose their ability to process visual information in this time. Richard Schweitzer and Martin Rolfs at Humboldt University of Berlin in Germany have shown that this isn’t the case: we are, in fact, able to absorb information from our surroundings during such rapid eye movements. “This kind of changes the way we approach perception because we used to think about motor actions and perception as two distinct things,” says Rolfs. “What this insight shows, I think, is that as we continue to interact between how we move and what we perceive, that it’s not two separate processes. It’s two things working together; they go hand in hand.” The pair worked with 20 volunteers who were asked to seek out and focus on a visual target displayed on a screen, which naturally encouraged their eyes to dart around performing saccades. However, the target on the screen was shown using a high-speed projector that was capable of generating about 70 images during each 50-millisecond-long saccade. This meant the researchers could have the target move smoothly so that its position at the end of the saccade was different from its position at the start. The volunteers detected this within-saccade movement: at the end of the saccade, when their eyes looked for the target again, they seemed to have anticipated where the target would now be located. The researchers could confirm this because the volunteers were able to correct their eye movement to locate the target more quickly than would have been the case had their eyes not detected the target’s movement during the saccade.

7-23-21 Covid vaccine: Eight-week gap seen as sweet spot for Pfizer jab antibodies
A longer gap between first and second doses of the Pfizer-BioNTech Covid vaccine makes the body's immune system produce more infection-fighting antibodies, UK researchers have found. Experts say the findings support the UK's decision on extending dosing intervals from the initial recommendation of three weeks. An eight-week gap seems to be the sweet spot for tackling the Delta variant. The UK initially extended the dosing gap to 12 weeks at the end of 2020. But as the vaccination programme has been rolled out through the age groups - everyone over 18 has now been offered at least their first jab - people have been encouraged to bring their second jab forward and get it after eight weeks. The government-funded work is published in a pre-print paper not yet peer reviewed. For the study, the researchers compared the immune responses of 503 NHS staff who received their two shots at different intervals in late 2020 and early 2021, when the Alpha Covid variant, first identified in Kent, was rapidly spreading. Antibody levels in their blood were measured a month after the second vaccine dose. The findings suggest: 1. both short and long dosing intervals of the Pfizer vaccine generated strong immune responses overall, 2. a three-week schedule generated fewer of the neutralising antibodies that can bind the virus and stop it infecting cells than a 10-week interval, 3. while antibody levels dipped after the first dose, levels of T-cells - a different type of immune cell - remained high, 4. the longer schedule led to fewer T-cells overall but a higher proportion of a specific type or subset, called helper T-cells, which according to the researchers, supports immune memory. Prof Susanna Dunachie, the joint chief investigator in the Pitch study, at Oxford University, said two doses were better than one but the timing of the second was somewhat flexible depending on the circumstances.

7-23-21 A partial skeleton reveals the world’s oldest known shark attack
A man encountered the animal 3,000 years ago off the coast of Japan. Somewhere off southeastern Japan’s coast around 3,000 years ago, a shark attacked and killed a man who was likely fishing or shellfish diving. Afterward, the victim’s fishing comrades presumably brought the body, minus its sheared off right leg and left hand, back to land for burial. A new analysis of that unfortunate man’s partial skeleton, excavated around a century ago at a village cemetery near Japan’s Seto Inland Sea, has unveiled that grisly scenario. This individual from Japan’s ancient Jomon culture (SN: 2/15/97) represents the oldest known human victim of a shark attack, say archaeologist J. Alyssa White of the University of Oxford and colleagues. Radiocarbon dating places his death from 3,391 to 3,031 years ago, the researchers report in the August Journal of Archaeological Science: Reports. A roughly 1,000-year-old skeleton of a fisherman on Puerto Rico previously displayed the earliest signs of a shark encounter. White’s group documented at least 790 gouges, punctures and other types of bite damage mainly confined to the Jomon man’s arms, legs, pelvis and ribs. A 3-D model of these injuries indicates that the victim first lost his left hand trying to fend off a shark. Ensuing bites severed major leg arteries, rapidly leading to death. After the man’s body was recovered, his mutilated left leg probably detached and was placed on his chest when he was buried, the researchers say. Numerous shark teeth found at some Jomon sites suggest that sharks were hunted, perhaps by drawing them to blood while fishing at sea. “But unprovoked shark attacks would have been incredibly rare as sharks do not tend to target humans as prey,” White says.

7-23-21 Pterosaurs may have been able to fly as soon as they hatched
A fossil analysis shows the hatchlings had a stronger bone crucial for lift-off than adults. Pterosaur hatchlings may have been able to fly right out of the shell — although the flight of those ancient baby reptiles might have looked a bit different from that of the adults. A new analysis of the fossilized wing bones of embryonic, newly hatched and adult pterosaurs suggests the baby creatures were strong and nimble fliers from the start, researchers report July 22 in Scientific Reports. Pterosaurs were a diverse group of ancient flying reptiles that lived alongside dinosaurs from the Triassic to the Cretaceous periods, 228 million to 66 million years ago. The group includes Quetzalcoatlus northropi, the largest creature known to take wing, and Kunpengopterus antipollicatus (aka “Monkeydactyl”) which had opposable thumbs that enabled it to climb trees (SN: 4/14/21). Scientists know relatively little about the early life history of pterosaurs, including whether their young could actively flap their wings or only glide — which might mean they stayed under parental care until they were flight-ready. But recent revelations increasingly point toward early independence, or “precociality,” for the reptiles, such as finding flight membranes on the wings of an embryonic pterosaur, and the discovery of a tiny Pteranodon juvenile that was capable of long-distance flying long before it had grown to adult size. “Baby pterosaurs almost certainly didn’t glide,” they flew, says Kevin Padian, a paleontologist at the University of California, Berkeley, who was not part of the new study. The three keys to flight, he says, are strong bones, sufficient muscle mass to stay in the air for a long time and sturdy keratin fibers in the skin of the wings, analogous to the feathers of birds. “We know little about the last two.” So researchers turned to the bones. Darren Naish, a paleontologist at the University of Southampton in England, and his colleagues compared fossilized embryo and hatchling wing measurements with those of adults from two species, Pterodaustro guinazui and Sinopterus dongi. The researchers analyzed wingspans, the strength of wing bones and how much load the wings could carry. In particular, they zeroed in on one wing bone, the humerus. That bone is found on the limbs pterosaurs use to launch themselves into flight and offers key information on whether a pterosaur was capable of getting off the ground.

7-22-21 Ancient Roman road discovered at the bottom of the Venice lagoon
An ancient and now submerged road has been discovered in the Venice lagoon in an area that would have been accessible by land 2000 years ago during the Roman era. Fantina Madricardo at the Marine Science Institute in Venice and her colleagues made the discovery after mapping the floor of an area of the lagoon called the Treporti channel. “We believe it was part of the network of Roman roads in the north-east of the Venice area,” says Madricardo. In the 1980s, the archaeologist Ernesto Canal proposed that there are ancient human-made structures submerged in the Venice lagoon. This suggestion prompted decades of debate, but couldn’t be confirmed until now as the previously available technology was insufficiently advanced to explore such a challenging environment. “The area is very difficult to investigate by divers because there are strong currents and the water in the Venice lagoon is very turbid,” says Madricardo. The team used a multibeam echosounder mounted on a boat to form a picture of what lies underwater. This device sends out acoustic waves that bounce off the lagoon floor, allowing the team to reconstruct images of whatever structures are down there. The researchers found 12 structures up to 2.7 metres tall and 52.7 metres long that extended along 1140 metres in a south-west to north-eastern direction in the configuration of a road. The presence and layout of these structures suggest that there may have been a settlement in the area. It was then submerged about 2000 years ago – partly due to human activity that diverted the flow of rivers and starved the area of the sediment that was needed to keep it above water. “Presumably, the road is giving access to this rich environment. The margins of the land and the water are full of resources that people might have been exploiting,” says James Gerrard at Newcastle University in the UK. “It’s not normal to find, if you like, ‘drowned’ landscapes or be able to study them in this kind of detail.”

7-22-21 The coronavirus cuts cells’ hairlike cilia, which may help it invade the lungs
Trimming the structures prevents mucus from moving the invaders out toward the throat. A coronavirus infection can mow down the forests of hairlike cilia that coat our airways, destroying a crucial barrier to keeping the virus from lodging deep in the lungs. Normally, those cilia move in synchronized waves to push mucus out of the airway and into the throat. To protect the lungs, objects that don’t belong — including viral invaders like the coronavirus — get stuck in mucus, which is then swallowed (SN: 9/15/20). But the coronavirus throws that system out of whack. When it infects respiratory tract cells, the virus appears to clear tracts of cilia, and without the hairlike structures, the cells stop moving mucus, researchers report July 16 in Nature Communications. That lack of cilia could help the virus invade the lungs and cause severe COVID-19, says Lisa Chakrabarti, a viral immunologist at the Pasteur Institute in Paris (SN: 6/11/20). Understanding how the coronavirus invades different parts of the body can help researchers find ways to block it. Chakrabarti and colleagues infected lab-grown human cells that mimic the lining of the respiratory tract with the coronavirus. Images showed short, stubby cilia on the surface of the infected cells rather than the long projections found on healthy cells. When the team added microscopic beads to the surface of infected cells to measure mucus movement, those beads largely stayed still — a sign that the cells wouldn’t move mucus through the respiratory tract and into the throat to be swallowed. Other viruses and bacteria can also damage the body’s ability to use mucus to trap and remove foreign invaders, Chakrabarti says. Some pathogens, like the coronavirus, just damage cilia, leaving the cells they protrude from intact. Other pathogens — like influenza — can kill ciliated cells. Respiratory syncytial virus, which typically causes colds, can do both: In adults, it destroys cilia; in children, it can kill the cells, which can be deadly.

7-21-21 Virtual roller coaster rides may help unravel causes of migraine
Virtual roller coasters set off altered brain cell activity related to dizziness and motion sickness in people who experience migraines, even if they aren’t currently having a migraine – a finding that could lead to a better understanding of migraines and the development of new treatments. Anyone can feel sick and dizzy when they take a ride on a roller coaster, but people who experience migraine headaches often feel sicker and dizzier on the thrill ride. And the more people feel motion sickness and a general sense of incapacitation from their migraines, the more their brain activity differs from normal during a roller coaster simulation, says Gabriela Carvalho at the University of Luebeck in Germany. “Our findings show that the brain areas related to… processing of migraine pain overlap with brain systems that regulate motion sickness and dizziness,” she says. “People with migraines don’t just have headaches; they also often experience other conditions like motion sickness and dizziness which can really affect their quality of life. So this study really gives us a better idea about what’s going on [in their brains].” Carvalho and her colleagues carried out functional magnetic resonance imaging (fMRI) on the brains of 40 people – half of whom regularly experience migraine headaches – as they watched realistic, animated videos of roller coaster rides on a screen inside the MRI scanner continuously for 35 minutes. The videos gave the point of view of a person sitting on the ride and included sounds of the car running on the tracks. Participants in both groups were 30 years old on average, and 80 per cent of both group members were female. None of the participants experienced migraines during the virtual rides, but 65 per cent of those in the “migraine” group reported on a questionnaire that they felt dizzy during the simulation, while just 30 per cent of those in the control group did.

7-21-21 What would become of dogs without humans? Here’s how they’d evolve
EVEN to their biggest fans, dogs can seem ridiculously lacking in survival skills. Rufus takes off at full pelt after a squirrel with an expression of great determination, only to reach a nearby tree long after the squirrel has scampered to safety. Bella barks ferociously at a metal statue of an elk. Poppy stalks a wind-blown paper bag down the pavement. Dickens refuses to go outside to urinate because it is raining. Jethro runs home with his tail between his legs when he encounters a wild animal nearby. Such anecdotes are a common source of amusement at dog parks, on social media and in dog-related conversations. But behind the laughter lurks an serious scientific question: if humans were to suddenly disappear from the scene, could dogs survive? After at least 14,000 years of domestication, could this species we have co-evolved with cope without provisions of food, care and regular cuddles? Intrigued by this question, we have explored it as a thought experiment in our upcoming book, A Dog’s World. Using evolutionary theory and the growing body of research on free-ranging dogs, we imagine a post-human future for pooches. We try to work out what they would look like; how they might forage, reproduce and raise young; the nature of their social lives; and the cognitive and emotional skills they would need to successfully navigate a world in which they must compete, cooperate and coexist with other animals. Where we wound up surprised us. Not only did it highlight the immense flexibility of our canine friends, it also revealed some important lessons about how humans can improve the lot of dogs while we are still here. Dogs are among the most successful species of mammal on the planet. A billion or so of them inhabit every corner of the globe, living in all sorts of places, from homes and urban metropolises to deserts, rainforests and high Tibetan plateaus. When asked to imagine a dog, most people in the UK and US will picture a pet on a leash, chasing a ball in a park or gobbling a bowl of food. In fact, only a small minority of the world’s dogs live as companion animals, whereas between 80 and 85 per cent live independently as feral, village, street or community dogs.

7-21-21 'Jurassic Pompeii' yields thousands of 'squiggly wiggly' fossils
"If they could squeal, I'm sure they would have done." Palaeontologist Tim Ewin is standing in a quarry, recalling the calamity that's written in the rocks under his mud-caked boots. "They tried to protect themselves, adopting the stress position of pulling their arms in," he continues. "But it was all in vain; you can see where their arms got snagged open, right up to the crown. They were pushed into the sediment and buried alive." There's a little smile creeping across Tim's face, and he's got reason to be happy. The misfortune that struck this place 167 million years ago has delivered to him an extraordinary collection of fossil animals in what is unquestionably one of the most important Jurassic dig sites ever discovered in the UK. We can't be precise about the location of the excavation for security reasons, but you'll recognise from the gorgeous, honey-coloured limestone that we're somewhere in Cotswold country. Things have changed a bit since Jurassic times, though. No quaint villages and dry-stone walls back then; these parts were covered by a shallow sea, maybe 20-40m deep. And it was a damn sight warmer than your traditional English summer. The movement of tectonic plates means Britain was roughly where North Africa is today. So you can imagine the types of creatures that would have been living on this ancient, near-tropical seafloor. Stalked animals called sea lilies were tethered to the bed in great "meadows". Their free-floating cousins, the feather stars, were ambling by, looking to grab the same particles of food. And down in the sediment, starfish and brittle stars were feeling their way across the bottom with their fives arms, no doubt bumping into the occasional passing sea urchin or sea cucumber. It's exactly this scene that's persevered in the rocks of our mystery quarry. The quantities involved are astonishing. Not hundreds, not thousands, but perhaps tens of thousands of these animals that scientists collectively call "the echinoderms". It's a great name, derived from the Greek for "hedgehog", or "spiny", "skin". What is a sea urchin, if not an "underwater hedgehog"?

7-20-21 Last meal of a man mummified in a bog reconstructed after 2400 years
An ancient man ate a simple meal of cooked cereals and fish before being hanged and dumped in a bog 2400 years ago. Tollund Man was roughly 40 years old when he died in what is now Denmark. He was probably offered as a human sacrifice, and the peat bog he was buried in mummified his body in extraordinary detail. Dozens of other Iron Age Europeans were sacrificed in the same way, and they are collectively referred to as “bog bodies”. Danish scientists first analysed Tollund Man’s intestinal contents shortly after his body was discovered in 1950. They found 20 plant species and one species of parasite. But now Nina Helt Nielsen at Museum Silkeborg in Denmark and her colleagues have run new analyses on the contents of Tollund Man’s large intestine, investigating plant fossils, pollen and – for the first time in any bog body – a full range of non-pollen microfossils, steroids and proteins. The research revealed the presence of intestinal worm proteins and eggs – belonging to whipworm (Trichuris), tapeworm (Taenia) and mawworm (Ascaris) – as well as the man’s partially digested dinner. He ate porridge made up of around 85 per cent barley, 5 per cent flax and 9 per cent seeds from a plant called pale persicaria. Food crust indicated that the porridge was slightly burned and had been cooked in a clay pot. About 20 other species represented less than 1 per cent of the whole meal and were probably consumed accidentally. Tollund Man had also eaten a fatty-boned fish, like eel. He probably picked up the parasites from eating poorly cooked meat and drinking unclean water well before his death, says Nielsen. As for his last meal, it was mostly ordinary for the time. “I’m pretty sure we would see something similar if we analysed the gut contents of other bog bodies,” says Nielsen – although the pale persicaria seeds might have been a special addition as part of a sacrificial ritual.

7-20-21 Missing Antarctic microbes raise thorny questions about the search for aliens
Seemingly lifeless soils highlight the difficulty of discovering nothing. Even in the harshest environments, microbes always seem to get by. They thrive everywhere from boiling-hot seafloor hydrothermal vents to high on Mt. Everest. Clumps of microbial cells have even been found clinging to the hull of the International Space Station (SN: 08/26/20). There was no reason for microbial ecologist Noah Fierer to expect that the 204 soil samples he and colleagues had collected near Antarctica’s Shackleton Glacier would be any different. A spoonful of typical soil could easily contain billions of microbes, and Antarctic soils from other regions host at least a few thousand per gram. So he assumed that all of his samples would host at least some life, even though the air around Shackleton Glacier is so cold and so arid that Fierer often left his damp laundry outside to freeze-dry. Surprisingly, some of the coldest, driest soils didn’t seem to be inhabited by microbes at all, he and colleagues report in the June Journal of Geophysical Research: Biogeosciences. To Fierer’s knowledge, this is the first time that scientists have found soils that don’t seem to support any kind of microbial life. The findings suggest that exceedingly cold and arid conditions might place a hard limit on microbial habitability. The results also raise questions about how negative scientific results should be interpreted, especially in the search for life on other planets. “The challenge comes back to this sort of philosophical [question], how do you prove a negative?” Fierer says. Proving a negative result is notoriously difficult. No measurement is perfectly sensitive, which means there’s always a possibility that a well-executed experiment will fail to detect something that is actually there. It took years of experiments based on multiple, independent methods before Fierer of the University of Colorado Boulder and his collaborator Nick Dragone, finally felt confident enough to announce that they’d found seemingly microbe-free soils. And the scientists intentionally stated only that they were unable to detect life in their samples, not that the soils were naturally sterile. “We can’t say the soils are sterile. Nobody can say that,” Fierer says. “That’s a never-ending quest. There’s always another method or a variant of a method that you could try.”

7-19-21 Meet the puzzle-solving gorillas shedding light on how speech evolved
There are many ways that our great ape relatives can remind us of ourselves: through their anatomy, cleverness and social relationships, for instance. But never has the resemblance been so striking for me as today, when I watch gorillas carrying out a very human past-time: solving puzzles. The gorillas in question live at Port Lympne Reserve in Kent in the UK. The task involves moving a hazelnut treat down a vertical maze using sticks or the inbuilt cogs, until it is released at the bottom. It is very similar to a game I loved as a child, called Downfall, still played today. The task is part of a research project by Gillian Forrester at Birkbeck, University of London. I have tagged along, ostensibly to learn about her work, but my real goal was seeing the gorillas. Never before have I had such a good look at these animals, as some of them cannot resist coming to the front of their enclosure to work doggedly away at the mazes. Tibs, a skilful older female, carefully selects sticks, breaks bits off to shorten them and nibbles off leaves. She determinedly moves the nuts around the course, clutching a bar for support with big leathery fingers that have surprisingly human-like fingernails. Her expression seems to reflect intense attention, like a person doing a jigsaw puzzle. The research is investigating an idea about the origins of language. Linguists debate whether the first languages were based on hand gestures rather than grunts. But Forrester’s team are investigating an even earlier stage in the process – the mental abilities that language built on. “There would have been stuff going on in our ancestors’ brains that we have extended for language,” says Forrester. “We’re trying to learn what kind of behaviours it was supporting previously.” One possibility, first suggested in 1991, is tool use, which has several features in common with language. They both involve sequences of precise physical movements – whether of the hands or the mouth and vocal cords. They also require breaking down a complex final goal into simpler intermediate ones and achieving those in the right order. “If you don’t put your words in the correct order the meaning will be obscured,” says Forrester.

7-19-21 Trilobite fossil shows it was attacked by a human-sized sea scorpion
About 453 million years ago, a trilobite might have escaped the claws of a hungry giant sea scorpion. That is according to palaeontologists who analysed an unusual fossil found in the Czech Republic. Trilobites flourished in the oceans from around 522 million to 252 million years ago before going extinct. These hard-bodied arthropods resembled woodlice and ranged between about 1 millimetre and 70 centimetres in length. About 20,000 trilobite species are known from the fossil record. Trilobite fossils with evidence of head injuries are rare, suggesting that most attacks to the head were fatal and that any trilobite attacked this way was then eaten by its attacker. But Oldrich Fatka at Charles University in the Czech Republic and his colleagues studied an unusual eye trauma in the fossilised head of a common trilobite species called Dalmanitina socialis and believe it survived a predator’s attack. Casts of the fossil’s inner and outer surfaces enabled the researchers to see that part of the eye was missing. They think either all or part of the eye was originally gouged away but repeated natural moulting of the animal’s exoskeleton helped the wound heal and allowed a much smaller eye to grow back. Other signs of injury and healing included scratches, a crescent-shaped scar and misshapen cheeks. The researchers say the damage isn’t explained by some problem with the moulting process itself, which is often a cause of abnormalities seen in trilobite fossils. They also ruled out genetic mutation because of signs of healing. The most likely explanation, the researchers think, is that the trilobite was attacked by a predator. In theory, that predator might have been a larger trilobite, an octopus-like cephalopod or a giant eurypterid “sea scorpion” – the fossil record shows that all were living in the region at the same time as the small trilobite.

7-17-21 Only a tiny fraction of our DNA is uniquely human
The result underscores how big of a hand interbreeding among ancient hominids had in shaping us. The genetic tweaks that make humans uniquely human may come in small parcels interspersed with DNA inherited from extinct ancestors and cousins. Only 1.5 percent to 7 percent of the collective human genetic instruction book, or genome, contains uniquely human DNA, researchers report July 16 in Science Advances. That humans-only DNA, scattered throughout the genome, tends to contain genes involved in brain development and function, hinting that brain evolution was important in making humans human. But the researchers don’t yet know exactly what the genes do and how the exclusively human tweaks to DNA near those genes may have affected brain evolution. “I don’t know if we’ll ever be able to say what makes us uniquely human,” says Emilia Huerta-Sanchez, a population geneticist at Brown University in Providence, R.I., who was not involved in the study. “We don’t know whether that makes us think in a specific way or have specific behaviors.” And Neandertals and Denisovans, both extinct human cousins, may have thought much like humans do (SN: 2/22/18). The results don’t mean that individual people are mostly Neandertal or Denisovan, or some other mix of ancient hominid. On average, people in sub-Saharan Africa inherited 0.096 percent to 0.46 percent of their DNA from ancient interbreeding between their human ancestors and Neandertals, the researchers found (SN: 4/7/21). Non-Africans inherited more DNA from Neandertals: about 0.73 percent to 1.3 percent. And some people inherited a fraction of their DNA from Denisovans as well. Using a new computational method, researchers at the University of California, Santa Cruz examined every spot of DNA in the genomes of 279 people. The team compiled results from those individual genomes into a collective picture of the human genome. For each spot, the team determined whether the DNA came from Denisovans, Neandertals or was inherited from a common ancestor of humans and those long-lost relatives.

7-16-21 Just 1.5 to 7 per cent of the modern human genome is uniquely ours
Modern humans have been around for about 350,000 years. In that time, we have continued to evolve and our DNA has changed – but, only a small per centage of our genome may be unique to us. Nathan Schaefer at the University of California, San Francisco, and his colleagues created a tool called the Speedy Ancestral Recombination Graph Estimator (SARGE), which allowed them to estimate the ancestry of individuals. More specifically, it helped identify which bits of the modern human genome aren’t shared with other hominins – meaning they weren’t present in the ancient ancestors we shared with Neanderthals and Denisovans, and also haven’t been introduced to the human gene pool through interbreeding with these ancient humans. “Instead of building a tree across the genome that shows how a bunch of genomes are related on average genome-wide, we wanted to know what the ancestry of individuals looks like at specific sites in the genome,” says Schaefer. “We basically wanted to be able to show how everyone is related at every single variable position in the genome.” The team analysed one Denisovan, two Neanderthal, and 279 modern human genomes to distinguish what parts of the genome separate modern humans from archaic hominins. They found that only 1.5 to 7 per cent of the modern human genome is unique to us. The figure may seem low but that is partly because we inherited plenty of DNA from the ancient ancestral species that ultimately gave rise to modern humans and the Neanderthals and Denisovans. What’s more, modern humans then interbred with Neanderthals and Denisovans, picking up even more DNA that isn’t unique to our lineage. “It’s true that individual humans have a very low per cent of their genome that might have been from Neanderthal or Denisovan ancestry – non-Africans can have between 1.5 to 2.1 per cent of their genome that originated from Neanderthal ancestry,” says Schaefer.

7-16-21 Cannabis was domesticated in north-west China around 12,000 years ago
Cannabis was domesticated in what is now north-west China around 12,000 years ago, according to an analysis of the genomes of 110 plants from around the world. “It confirms it is one of the oldest cultivated plants,” says Luca Fumagalli at the University of Lausanne in Switzerland. “We think it was a multipurpose plant. It was exploited for fibre, food and oil, and possibly medical and recreational purposes.” It was only around 4000 years ago, the study suggests, that farmers started breeding distinct strains for drug or fibre production. Little has been known about the domestication of Cannabis sativa because it is hard to get hold of the wide range of different strains from around the world needed for genetic studies. “You can’t just go and collect samples because you go to jail,” says Fumagalli. Many sources suggest that cannabis originates in central Asia because many strains grow wild in the region. But it grows readily just about anywhere, he says. “That’s why it’s called weed.” Fumagalli worked with researchers around the world to collect and sequence some 80 different kinds of cannabis plants cultivated by farmers or growing wild. The team also included 30 previously sequenced genomes in the analysis. The original wild ancestor of cannabis appears to be extinct but strains growing in north-west China are its closest living relatives, the team found. The genomic dating of around 12,000 years fits well with archaeological evidence, including pottery with hemp cord markings on it appearing from around this time. The team identified many of the genetic changes brought about by selective breeding by farmers. For instance, hemp strains bred for fibre production have several mutations that inhibit branching. These plants grow taller and have more fibre in the main stem.

7-16-21 Human cells make a soaplike substance that busts up bacteria
A surprising cellular defensive strategy could inspire new antibiotics. When faced with bacterial invaders, some human cells dispense a surprising substance: soap. These cells, which aren’t part of the immune system, unleash a detergent-like protein that dissolves chunks of the inner membranes of bacteria, killing the infiltrators, researchers report in the July 16 Science. The “professional” players of the immune system, like antibodies or white blood cells, get lots of attention, but “all cells are endowed with some ability to combat infection,” says John MacMicking, an immunologist at Yale University. In humans, these run-of-the-mill cellular defenses have often been overlooked, MacMicking says, even though they are part of “an ancient and primordial defense system” and could inform the development of treatments for new infections. Often, nonimmune cells rely on a warning from their professional counterparts to combat infections. Upon detecting outsiders, specialized immune cells release an alarm signal called interferon gamma. That signal rouses other cells, including epithelial cells that line the throat and intestines and are often targeted by pathogens, to action. MacMicking and colleagues looked for the molecular basis of that action by infecting laboratory versions of human epithelial cells with Salmonella bacteria, which can exploit cells’ nutrient-rich interior. Then, the team screened over 19,000 human genes, looking for those that conferred some protection from infection. One gene, which contains instructions for a protein called APOL3, stood out. When this gene was disabled, the epithelial cells succumbed to a Salmonella infection, even when warned by interferon gamma. Zooming in on APOL3 molecules in action inside host cells with high-powered microscopy, the researchers found that the protein swarms invading bacteria and somehow kills them.

7-16-21 What 20th century science fiction got right and wrong about the future of babies
Storytellers have long predicted a technology takeover of human reproduction. Science fiction writers have imagined just about every aspect of life in some far-off future — including how humans will reproduce. And usually, their visions have included a backlash against those who tamper with Mother Nature. In his 1923 stab at speculative fiction, for instance, British biologist JBS Haldane said that while those who push the envelope in the physical sciences are generally likened to Prometheus, who incurred the wrath of the gods, those who mess around with biology risk stirring something far more pointed: the wrath of their fellow man. “If every physical or chemical invention is a blasphemy,” he wrote in Daedalus, or Science and the Future, “every biological invention is a perversion.” Some of Haldane’s projections were remarkably specific. He wrote, for instance, that the world’s first “ectogenic babies” would be born in 1951. These lab-grown babies would come about when two fictitious scientists, “Dupont and Schwarz,” acquire a fresh ovary from a woman who dies in a plane crash. Over the next five years, the ovary produces viable eggs, which the team extracts and fertilizes on a regular basis. Eventually, Haldane writes, Dupont and Schwarz solve the problem of “the nutrition and support of the embryo.” Soon lab-grown babies become routine, as scientists learn to remove an ovary from any living woman, maintain it in the lab for up to 20 years, extract a new egg every month, grab some sperm (from where, he never says), and successfully fertilize 90 percent of the eggs. Then — and here the details get murky — the embryos are “grown successfully for nine months, and then brought out into the air.” In Haldane’s imaginary future, 60,000 babies a year are “brought out into the air” in France, the first country to adopt the new technology, by the year 1968. At some later date, he wrote, ectogenic babies go international, and become more common than natural births, with only 30 percent of children “born of woman.”

7-15-21 Legal lead levels in US tap water may harm people with kidney disease
Drinking water containing levels of lead below the threshold level that warrants regulatory action in the US may be associated with worse health in people with advanced kidney disease. “For individuals with heightened susceptibility to lead exposure, such as those with chronic kidney disease, there is no safe amount of lead contamination of drinking water,” says John Danziger at Beth Israel Deaconess Medical Center in Massachusetts. Danziger and his colleagues analysed health information from 597,968 patients with chronic kidney disease in the US who started dialysis between 2005 and 2017, as well as official data on lead concentrations in city water systems in the five years leading up to their dialysis initiation. The team found that those who lived in cities with detectable levels of lead in the water systems had significantly lower concentrations of the oxygen-transporting protein haemoglobin in their blood before starting dialysis and during the first month of the therapy than people who lived where lead wasn’t detectable in the water. Lead is known to interfere with the ability of blood cells to produce haemoglobin, increasing the risk of anaemia. Every 0.01 milligram per litre increase in lead concentration in the water was associated with a 0.02 gram per decilitre reduction in haemoglobin concentration in people’s blood. The trend was observed even at lead levels below the US Environmental Protection Agency’s threshold of 0.015 milligrams per litre, which mandates regulatory action that can include public education, water treatment and lead service line replacement. “More comprehensive surveillance of household water is critical,” says Danziger. He and his team also found that Black people were exposed to higher water lead levels on average than white people, which is consistent with previous research revealing racial disparities in exposure to lead and other contaminants. Danziger says this inequality is compounded by the fact that Black people in the US experience higher rates of kidney disease, which may heighten their susceptibility to the effects of lead exposure.

7-15-21 Weird ‘Borg’ DNA found in microbes takes in genes from other organisms
A strange new genetic entity has been discovered in methane-eating microbes, and it could help fill in a gap in our understanding of Earth’s climate. Named “Borgs” after Star Trek aliens that assimilate the biology of other creatures, these enigmatic stretches of DNA inhabit single-celled organisms called archaea, where they appear to acquire and swap genes and potentially boost their hosts’ ability to consume methane, one of the most potent greenhouse gases. “These Borgs seemingly represent a new type of genetic element,” says Thijs Ettema at Wageningen University & Research in the Netherlands, who wasn’t involved in the study. Scientists have long known about mobile genetic elements, pieces of genetic material that can either move around a host’s genome or sit alongside it and travel between cells. They include plasmids – circular bits of DNA that microbes often exchange with each other – and phages, viruses that infect bacteria and archaea. Jillian Banfield at the University of California, Berkeley, and her colleagues were using DNA sequencing to study microbial communities living in oxygen-free mud when they stumbled across some unusual stretches of DNA. The team painstakingly stitched these together and reconstructed the full sequences of four Borg elements, naming them Purple, Black, Sky and Lilac. Studies of other samples revealed the existence of a further 15 types. “The thing that strikes you first is, they’re huge. I mean really huge,” says Banfield. At up to about 1 million DNA letters long – a third the size of their host’s genome – they are the largest mobile genetic element yet found in archaea or bacteria. Their structure is strange too: for example, unlike circular plasmids, Borg DNA is linear and contains many sections of repeated sequences. None of the proteins coded in the Borg genomes look like proteins seen in plasmids or viruses, nor do the DNA replications start in the usual sites seen in known plasmids. All in all, they look like something completely new.

7-15-21 Millions of kids have missed routine vaccines thanks to COVID-19
The COVID-19 pandemic has forced millions of children around the world to miss out on important childhood vaccinations, increasing the risk of dangerous outbreaks of other infectious diseases, new research suggests. Amid the spread of the coronavirus, an estimated 9 million more children than expected didn’t get a first dose of the measles vaccine in 2020, researchers report July 14 in a modelling study in the Lancet. Another 8.5 million children are projected to have missed a third dose of the DTP shot for diphtheria, tetanus and pertussis, or whooping cough. The World Health Organization and other public health agencies warned last year that the COVID-19 pandemic would disrupt routine childhood vaccinations. Those missing vaccinations could put vulnerable children at risk during outbreaks of highly contagious diseases, like the 2014 measles outbreak at Disneyland in California (SN: 11/13/20). The news also comes as health officials in Tennessee plan to halt all outreach to get adolescents vaccinated to prevent not only COVID-19 but also other infectious diseases. “We’ve lost over 4 million people to COVID,” says Suzette Oyeku, a pediatrician at the Children’s Hospital at Montefiore and Albert Einstein College of Medicine, both located in New York City. “How many additional lives do we want to lose for not protecting people against stuff that we know we can protect?” There is some uncertainty in the new Lancet estimates because vaccine data weren’t available for all countries, says global health researcher Kate Causey of the University of Washington’s Institute for Health Metrics and Evaluation in Seattle. The actual numbers for some regions could be lower or higher. A separate analysis from WHO and UNICEF, described in a July 15 press release, does find lower numbers, though millions of children are still missing crucial childhood vaccines.

7-14-21 The mysterious case of declining nutrition in food
I LOVE playing detective. So when I found myself on a train scrolling through hundreds of shocked responses to yet another viral tweet claiming that the proportion of nutrients in our fruit and veg has collapsed over recent decades, I thought I better do some digging. This ubiquitous, yet generally poorly evidenced, claim is one that I have explored in a previous column. However, as the new tweet cited a 2018 study that is more recent than many I have looked into before, it seems important to return to the issue, particularly given its new-found influence on social media. After all, one of the hallmarks of good science is the flexibility to change your stance as new evidence surfaces. So, with a 4-hour journey ahead of me, I started delving into the stats used to underpin this claim. Centred on a steep line graph extracted from a paper (doi.org/gf75hz) published in the journal Nutrients, this tweet suggested there has been a catastrophic collapse in the average levels of calcium, magnesium and iron in cabbage, lettuce, tomatoes and spinach of up to 90 per cent in the past hundred years. With a link to the paper in an academic journal, it outwardly seemed very convincing. So why did it pique my interest? Well, as a botanist fascinated by food crops and how they have shaped human history, understanding how the handful of plants on which civilisations are built have changed over the centuries is one of my key research areas. The only problem is that it is very hard to study. One of the biggest problems we have when it comes to answering what can seem like simple questions about things like nutrient density in crops is finding like-for-like comparisons to establish how these change over time. There are so many factors that have a measurable impact on crop chemistry, including weather, soil make-up, harvest stage and the unique genetics of a crop, that agreeing on a universal value for a “typical” tomato today is a challenge, let alone doing the same for one more than a century ago. It is rather like picking a random New Yorker and expecting them to be representative of not just every other inhabitant of the city, regardless of race, gender, age, class, education or income, but all of humanity.

7-14-21 Easing England's covid-19 lockdown puts children in the firing line
IF THERE has been one saving grace of the covid-19 pandemic, it is that children are relatively safe from serious disease and death compared with adults. Over the first year of the pandemic, only 259 under-18s in England were admitted to intensive care with covid-19. Another 312 were treated for a serious but rare condition that developed after infection called delayed inflammatory syndrome. As the UK government prepares to lift nearly all covid-19 restrictions in England on 19 July and allow the virus to spread through the community (see Covid-19 deaths in England could peak at 100 per day in August), it might seem as if children aren’t at risk, but this isn’t the case. Under-18s make up a fifth of the UK population and very few have been vaccinated, because unlike countries such as the US, which is offering covid-19 vaccines to children who are 12 and over, the UK has decided to hold off (see Is it time for the UK to vaccinate children against covid-19?). Cases of covid-19 in the UK are growing fast, and with more than half of the adult population vaccinated, the spread of the virus will be driven into younger people, especially unvaccinated children. Effectively, the government is pursuing a “natural herd immunity” strategy, in which children are exposed to the virus until nearly all of them develop immunity. If children are at low risk of dying, does this matter? Well, when very large numbers of people are exposed to the virus, many will get ill and some will die. In the case of children, those at highest risk are those with underlying medical conditions. In the first year of the pandemic, 25 children died in the UK from either acute covid-19 or the delayed inflammatory syndrome, and that was while restrictions were in place. In addition, some 13 per cent of infected children develop persistent and sometimes debilitating symptoms. Letting the virus rip through a pool of unvaccinated people also increases the risk of a new variant emerging that can evade the protection from the vaccines we have. We have argued many times in the pages of this magazine against taking this kind of herd immunity approach to the pandemic. The same logic applies to children.

7-14-21 The fight against coronavirus needs to embrace evolutionary theory
EARLIER this year, Dido Harding, whilst heading England’s coronavirus test and trace system, said that no one could have predicted that new variants of SARS-CoV-2, the virus that causes covid-19, would emerge. Of course this was predicted, and while some people questioned Harding’s statement, many still seem surprised that the virus continues to mutate. With covid-19, we have taken a largely reactive approach to new variants. As each emerges, we evaluate the genomic changes, and then attempt to establish whether these mean it represents a greater health threat. But it is critical that we start to take evolution, rather than just genetic change, into account, especially given the recent announcement that cases could reach 100,000 per day in the UK as it opens up – accelerating the rate at which new variants may emerge. In long-lived organisms, like humans, individual genetic mutations don’t tend to have much of an effect. But among viruses, even one mutation can drastically affect its fitness – how well it is adapted to host species. This is why a fast-evolving virus like influenza consistently stays ahead of our best efforts to vaccinate against it. The connection between an organism’s genetic make-up and its environment is the bedrock of what is known as the modern synthesis of evolutionary biology. According to the modern synthesis, random genomic changes that increase fitness in a given environment will inevitably become more common. Modern evolutionary theory takes a similar approach. In behavioural ecology, for example, researchers have adopted what is known as the phenotypic gambit. This concept, whose name comes from a chess strategy of sacrificing a piece for tactical gain, assumes that changes in phenotype – which are measurable features, like eye or hair colour – are governed by genetic change. But the gambit stops there: we sacrifice knowledge of the particular genetic change, and focus instead on observable features alone when talking about fitness.

7-14-21 How medical tests have built-in discrimination against Black people
THE assumption that Black people have a lower level of cognitive function than white people was, until recently, built into a formula used by the US National Football League to settle head injury lawsuits. The NFL has now pledged to stop using this “race-norming” formula, but race-based adjustments in routine diagnostic tests remain pervasive in mainstream medicine. Although some scientific organisations are working to remove such adjustments, many contacted by New Scientist declined to take a stance on the issue, which is growing in prominence. Race-norming was first established in the 1990s by psychiatrist Robert Heaton at the University of California, San Diego, as a way to try to account for the way African American people tended to score lower than white people on cognitive tests, which are commonly used to diagnose conditions such as dementia. Subsequent research has shown that adjusting cognitive test performance to take social factors – such as education quality- into account significantly reduces this variance by race. Despite this, Katherine Possin at the University of California, San Francisco, says that race-norming of cognitive tests is still widely practised by doctors in the US today, something she says is extremely problematic. Heaton says that although observed differences in test performance between subgroups of the US population may be explained by racial discrimination, stressful life experiences, a lack of consistent access to good nutrition and healthcare, and limited educational opportunities, measuring these directly is too hard. “These are extremely difficult to measure, quantify and ‘correct for’ in interpreting test results,” said Heaton in a written statement to New Scientist. “The fact remains, that a very substantial amount of variability in the test performance of normal adults can be ‘explained’ (accounted for) by the demographic variables of age, education, sex, and race/ethnicity (together), so our best available norms ‘correct’ for these characteristics.”

7-14-21 The lowdown on stretching: How flexible do you actually need to be?
Many people strive to touch their toes or do the splits, but it is perfectly possible to get all the benefits of stretching without pushing your body to its limits “I BEND so I don’t break.” No one knows who first coined this phrase, but search for it online and you will find it accompanying numerous pictures of yogis in various states of contortion. Flexibility, according to common wisdom, is not only impressive to look at, but something we should actively work towards. Scientifically, however, the question of whether we should stretch to become more flexible has been difficult to answer. Assumptions about the benefits of stretching to prevent sports injuries and greater flexibility being better for our overall physical fitness hadn’t been confirmed by studies. Does it matter if you can’t touch your toes, let alone do the splits? Even in sports science, where most of the research has been conducted, there has been little agreement. In recent years, though, answers have started to emerge. The surprising outcome is that, while stretching may well be good for us, it is for reasons that have nothing to do with being able to get your leg behind your head. One thing is for sure: stretching feels good, particularly after a long spell of being still. We aren’t the only species to have worked this out. As anyone with a dog or cat will know, many animals take a deep stretch after lying around. This kind of stretching, called pandiculation, is so common in nature that some have suggested it evolved as a reflex to wake up the muscles after a spell of stillness. Pandiculation aside, other species don’t seem to spend any time maintaining and extending their range of motion. Which raises the question, is there any reason why we should?

7-13-21 Some people can tell if you have an infection just by looking at you
People across cultures can tell when others are in the early stages of infection by looking at them. Artin Arshamian at the Karolinska Institute in Stockholm, Sweden, and his colleagues tested whether it was possible to tell if someone was sick just by looking at their face. The team worked with 169 volunteers from six different cultural backgrounds, including city dwellers in Stockholm and hunter-gatherers in the rainforests of Thailand and Malaysia, and in the coastal deserts of Mexico. Each volunteer was shown photos of Swedish people taken 2 hours after they had been injected with either Escherichia coli or a placebo. Those who had been injected with E. coli were at the beginning stages of an immune response when their photos were taken – and some of the volunteers in all six groups had a better-than-chance ability to identify that they were sick. The ability to tell who is sick at an early stage could benefit us by helping us decide whether to avoid certain people, says Joshua Tybur at VU University Amsterdam in the Netherlands. “This could also be useful for people you care about, to know when they need more help,” he says. “The most dangerous thing is if you get contact with pathogens that your immune system has little experience with,” says Arshamian. “That’s one of the problems when new populations come in and mix – they can bring pathogens to groups that have very little exposure to these and that’s really bad. Basically, this is what happened to the Native Americans.” The team had thought that the volunteers from Stockholm would be the best at recognising sickness because the photos were of people from their own community, but this wasn’t the case. “I think what it means is that probably this is such a stable ability and such a general ability that cultural experience probably doesn’t affect it that much,” says Arshamian.

7-13-21 Finger sweat can power wearable medical sensors 24 hours a day
Small biofuel cells can harvest enough energy from the sweat on a person’s fingertips to power wearable medical sensors that track health and nutrition – and because our fingertips are one of the sweatiest parts of the body, the sensors could be powered all day. Lu Yin at the University of California, San Diego, and his colleagues created a device that breaks down a dissolved compound in sweat called lactate. It comprises biofuel cells that fit into thin pads that are stuck to the fingertips. They soak up sweat into a thin layer of foam, where an enzyme oxidises lactate in the sweat to create an electrical charge. Each finger pad can generate 20 to 40 microwatts of power and harvest 300 millijoules of energy per square centimetre during 10 hours of sleep. This isn’t enough to run power-hungry devices like smartwatches or mobile phones, but more than enough for lightweight sensors that detect a range of metrics such as heart rate, vitamin deficiencies and glucose levels. Researchers have created devices that are powered by sweat before, but they needed large volumes of the liquid, such as when a subject was jogging. The fingertips have the highest concentration of sweat glands on the body and produce continuous charge even if the wearer isn’t exercising. “Even with the minute amount of sweat compared to the sweat you got from a really intense workout, this power is still very sizeable,” says Yin. “No matter how clean your hand is, it’s very easy to leave your fingerprint everywhere. That’s basically the residue of your sweat, with a lot of metabolites. What we did is to take advantage of this.” Currently, the enzyme that is key to the reaction begins to break down and become ineffective after two weeks. Yin says that further research is needed to create a stable enzyme that can be used in permanent sensors.

7-13-21 Neuroscientists are ignoring the differences between males and females
Top neuroscience research papers are eight times more likely to only study male participants or samples compared with female-only studies, a review has found. In addition, only 4 per cent of papers look for sex differences in their data, suggesting that neurological disorders in women may be being overlooked. Liisa Galea at the University of British Columbia, Canada, and her colleagues analysed the sex of samples used in every new research paper published by three of the world’s most respected neuroscience journals between 2009 and 2019. “Many neurological and psychiatric disorders have sex differences in the prevalence of the disease,” says Galea, noting that depression is more common in women than men, for example. “On average, women are diagnosed two years later than men for the same disease,” she says. While there are a variety of reasons for this, Galea says one major factor is our lack of understanding in how men and women may present the same disease differently. The researchers looked at more than 2000 papers published in Nature Neuroscience, Neuron and Journal of Neuroscience. Their analysis included looking at the sex of rodents used, the sex of human participants and the type of fetal or cell lines studied. Around 21 per cent of the papers involved human subjects. It wasn’t known whether the studies in the review included transgender or intersex people. Studies looking at male and female sexes rose from 20 per cent in 2009 to 70 per cent in 2019, but only 4 per cent of the studies actually looked for sex differences in the data, because the female samples were too small to be effectively analysed. Galea and her team also found that just 3 per cent of the papers they looked at were female-only studies, compared with 25 per cent involving just male subjects.

7-13-21 ‘The Joy of Sweat’ will help you make peace with perspiration
Science journalist Sarah Everts’ new book revels in the science and history of sweat. The telltale darkened patches under our arms before a presentation. The cold slide of a clammy handshake. Sweat reveals what we often want to hide: our nervousness, fears and exertions, all with the slight odor of what we last ate. But maybe it’s time to find “serenity instead of shame” in sweat, argues science journalist Sarah Everts. Through her delightful book, The Joy of Sweat, Everts delivers what she calls a “perspiration pep talk” that drips with science and history. Everts’ plunge into sweat is full of energy, and her open curiosity about our much-maligned bodily secretion leaks onto every page. Temperature regulation through sweat, she notes, is a trait few species can boast. Every drop tells the tale of our evolution — our ability to keep our cool has literally kept us alive and thriving. The book offers plenty of fascinating facts: Traces of drugs and diseases appear in our perspiration. Tiny drops of sweat create the fingerprint smudges used to identify us. Sweat may even hold clues about the nutritional content of what we eat. While sweat “keeps us honest,” Everts writes, it also raises questions. For instance, how long until companies start mining the potential data dripping off people’s foreheads? Forget the smell of stinky feet — we may soon have to worry about the privacy implications of sweating in public. But Everts is never too serious. She gamely gets her armpits professionally sniffed, and she joins naked, sweating audiences for sauna theater. She even goes smell-dating, working up a sweat in a crowd so potential mates could sniff for love — or at least, attraction. These stories amuse, but a more profound point lingers. People collectively spend billions of dollars each year deodorizing, wicking sweat away and pretending with all their might that it doesn’t exist. The Joy of Sweat shows how this demand was created by deodorant and antiperspirant makers who sold sweat as a problem in the first place. The clear advertising spin will make readers reflect on how much of our hygiene habits are the result of manufactured humiliation. By highlighting history, Everts shows that any perceived problems of sweat are most often cultural, not biological. Sweat simply is “a body trying its best to do its thing,” she writes. And if we let that message seep into our minds (and out our armpits), we too can revel in the joy of sweat.

7-12-21 A simple word test can reveal how creative you are
Are you a creative person? This question is difficult to answer objectively, but now researchers say that asking people to name random words and assessing how different they are could be a new way to measure creativity. Jay Olson at Harvard University and his colleagues call this word puzzle the Divergent Association Task (DAT), because it measures divergent thinking, a component of creativity involving generating diverse solutions to open-ended problems. Traditionally, researchers have used two main approaches to assess creativity. One is to give someone a questionnaire that quantifies about their achievements in a range of activities such as cooking, writing, painting and performance. The other is to give them a task that directly assesses a person’s creative thinking capabilities, but these are often laborious and subjective, for example asking people to list novel uses of a common household object. To test DAT as an alternative, the team asked 8914 people across 98 countries to list 10 nouns with the goal of choosing words with meanings as different from each other as possible. The researchers used a machine learning algorithm to calculate the average semantic distance between the words, based on how often they are used in similar contexts across billions of websites – for example, “cat” and “dog” and more closely related than “cat” and “book”. The team also asked the participants to take traditional creativity measuring tests, and found that people who scored higher on the DAT also scored higher on these tests. The DAT was up to 12 times better at explaining the variation in scores between other creativity tests, suggesting it is a valid measure of creativity. Overall, the DAT set the highest score in comparison to any of the other measures. Olson hopes the DAT will serve as a simpler and faster task to complete and score, allowing researchers to measure creativity in large numbers of people more easily.

7-12-21 One mutation may have set the coronavirus up to become a global menace
A study pinpoints a key change that may have put a bat coronavirus on the path to infect people. A single change in a key viral protein may have helped the coronavirus behind COVID-19 make the jump from animals to people, setting the virus on its way to becoming the scourge it is today. That mutation appears to help the virus’ spike protein strongly latch onto the human version of a host protein called ACE2 that the virus uses to enter and infect cells, researchers report July 6 in Cell. That ability to lock onto the human cells was stronger with the mutated virus than with other coronaviruses lacking the change. What’s more, the mutated virus better replicates in laboratory-grown human lung cells than previous versions of the virus do. “Without this mutation, I don’t think the pandemic would have happened like it has,” says James Weger-Lucarelli, a virologist at Virginia Tech in Blacksburg. The coronavirus’s global spread might have been less likely, he says. Where exactly the coronavirus came from is still a mystery that researchers are trying to unravel (SN: 3/18/21). But figuring out how an animal virus gained the ability to infect people could help researchers develop ways to prevent it from happening again, such as with antivirals or vaccines, Weger-Lucarelli says. The new findings hint that the mutation is important, but “it’s potentially one of multiple” changes that made the jump from animals to people possible, says Andrew Doxey, a computational biologist at the University of Waterloo in Canada who was not involved in the study. “It’s not necessarily the only mutation.” Virologist Ramón Lorenzo Redondo agrees. The researchers employed an approach that is not typically used for viruses, says Redondo, of Northwestern University Feinberg School of Medicine in Chicago. That means the method may have overlooked other important mutations.

7-12-21 How science overlooks Asian Americans
The pandemic put Asian Americans in a spotlight — and revealed how little is known about them. For years, sociologist ChangHwan Kim has sought to characterize the lives and experiences of Asian Americans. Gatekeepers in the research community, though, have often scoffed at his focus on a demographic group that looks like the picture of success in terms of education, earnings, health and other variables (SN: 4/14/21). “In my experience, if I have a study with only Asian Americans, journals are reluctant to publish that work,” says Kim, of the University of Kansas in Lawrence. An apparent lack of interest in studying Asian Americans isn’t limited to sociology; it even appears in medical research. At about 23 million people, Asian Americans represent about 7 percent of the U.S. population and are the fastest-growing demographic group in the country. Yet just 0.17 percent of the National Institutes of Health’s roughly $451 billion research funding between 1992 and 2018 went to clinical studies that included a focus on Asian Americans, researchers reported in 2019 in JAMA Network Open. Over the last year, politicians’ use of racial epithets, such as “China virus” and “kung flu”, to refer to COVID-19, alongside a surge in violence against Asian Americans, has thrust this population into the media spotlight. This attention is “a new phenomenon,” Kim says. That media gaze has showcased just how little is known about Asian Americans and, consequently, how to best meet the population’s needs. Asian Americans’ invisibility in public and scientific discourse stems from the majority-minority paradigm, Kim says. This sociological paradigm frames white Americans, the majority, as better off than minority groups across several metrics, including educational outcomes, wages and family stability. So studies of minorities often focus on issues related to marginalization and inequality. Asian Americans do not appear to fit the paradigm. “Minorities are doing worse than whites. That’s what people want to talk about,” Kim says. “Studies on Asian Americans make things complicated.”

7-9-21 50 years ago, scientists found a virus lurking in human cancer cells
Excerpt from the July 10, 1971 issue of Science News. [Researchers] cultured and isolated the … virus from tissue of a child patient with Burkitt’s lymphoma — cancer of the lymph nodes.… [The] work reinforces the growing body of evidence that human cancers are linked with, or caused by, a virus or viruses.… And it once again raises the possibility of a cancer vaccine. Scientists estimate that a handful of viruses cause around 12 to 20 percent of human cancers. Vaccines are now available for hepatitis B virus, which can cause liver cancer, and human papillomavirus, responsible for most cervical cancers. But a vaccine for the first virus ever linked to cancer has eluded scientists. Epstein-Barr virus, or EBV, infects about 90 percent of people and can cause Burkitt’s lymphoma and other cancers in a small fraction of those infected. Developing a vaccine has been a challenge partly because EBV can hide in the body for decades before causing problems. Several vaccine candidates are being tested in people, including one nanoparticle-based vaccine that may trigger a potent immune response.

7-9-21 Stone Age Europeans may have worn make-up more than 6000 years ago
Some late Stone Age Europeans may have carried make-up inside miniature bottles that they wore around their necks or waists more than 6000 years ago. Researchers have discovered traces of ingredients known to be used in cosmetic formulations by later civilisations inside small bottles unearthed in Slovenia, dating to between 4350 and 4100 BC. The finding suggests that lead-based cosmetics were possibly used in Europe more than 2000 years earlier than previously thought, and more than 1000 years before the earliest evidence of their use from ancient Egyptian and Mesopotamian cultures. In 2014, Bine Kramberger at the Institute for the Protection of Cultural Heritage of Slovenia found a miniature ceramic bottle at an ancient site once occupied by people of the Lasinja culture in around 4350 BC. More than 100 similar bottles have been found across 30 sites in central and south-eastern Europe. Their purpose was unknown, but it is thought that some might have been children’s toys due to their shapes, resembling animal or human heads. Curiously, most of them have holes in their tiny handles or rims that archaeologists think people threaded string through, enabling them to be worn around the neck or waist. But Kramberger’s find was different because it contained a solid white substance. “It was clear that it hid valuable information because in such old archaeological sites, we rarely find vessels that still retain remnants of their former content,” he says. Long and thin stone tools were found near the bottle, which could have been used to extract the substance within. “Miniature vessels were, for far too long, considered to be children-related, and there is no denial that some probably have been,” says Bisserka Gaydarska at Durham University in the UK. “But I know that there was a much more diverse use of small vessels, and medicinal and cosmetic containers is as good as any.”

7-9-21 How your DNA may affect whether you get COVID-19 or become gravely ill
A study of more than 45,000 people offers hints to why some people get sick after infection. Some people can blame their DNA for making them more likely to get COVID-19 or becoming severely ill if they get infected. A study of more than 45,000 people with COVID-19 has uncovered 13 genetic variants linked to an increased risk of infection with SARS-CoV-2 or a higher chance of developing severe illness, researchers report July 8 in Nature. The team includes more than 3,300 researchers in 25 countries. Some of the variants had been uncovered in previous studies. For instance, researchers again confirmed a genetic link between blood type and the likelihood of getting infected, but don’t know why people with type O blood may be slightly protected. The study also verified that a variant that disables the TYK2 gene raises the risk of critical illness and hospitalization. That variant is known to protect against autoimmune disease, but leaves people more vulnerable to tuberculosis. But at least one association was unknown: A variant in a gene called FOXP4 is associated with more severe COVID-19, the team found. That variant boosts the gene’s activity and has been previously linked to lung cancer and interstitial lung disease, a group of diseases that cause scarring and stiffness of the lungs. Yet-to-be-developed drugs that inhibit activity of FOXP4’s protein might help people recover from COVID-19 or prevent them from becoming very ill. The disease-associated version of the gene is more common among Asians and Latino populations in the Americas, geneticist Mark Daly said July 7 during a news briefing. This link might never have been discovered if people of diverse ancestries from around the world hadn’t been included in the study, said Daly, of the Institute of Molecular Medicine Finland in Helsinki (SN: 3/4/21). Only 2 percent to 3 percent of people with European ancestry carry the variant, compared with 7 percent of people in the Middle East, 20 percent of Latinos in the Americas and 32 percent of East Asians.

7-9-21 The gap in parenting time between middle- and working-class moms has shrunk
Well-educated mothers may be leveraging their resources, while protecting their finite time. Time is a finite resource. So it’s not entirely surprising that after decades of ramping up time spent on parenting, some well-educated mothers appear to have run out of extra minutes. Meanwhile, some less-educated moms have continued increasing their own parenting hours, a new study finds. As a result, a long-standing, class-related gap in mothers’ parenting time has shrunk, researchers report in the June 1 Demography. Specifically,the gap in time spent parenting between college-educated mothers versus mothers without a high school degree shrank by 57 percent, on average — from 44 minutes per day in the early 2000s to 19 minutes per day in the late 2010s. “Intensive parenting is no longer a middle-class phenomenon. It’s diffused across all groups,” says sociologist Jennifer Augustine of the University of South Carolina in Columbia. Time-intensive parenting seems to stem from inequality, or parents’ fears that their children will fall behind their peers absent such an approach, says Patrick Ishizuka, a sociologist at Washington University in St. Louis in Missouri, who was not involved in the new research. Ishizuka showed in the September 2019 Social Forces that parents across the socioeconomic spectrum consider deep investment in children the parenting ideal. In the new study, Augustine and family sociologist Kate Prickett of Victoria University of Wellington in New Zealand evaluated data from the American Time Use Survey, an annual evaluation collected by the U.S. Census Bureau that measures the amount of time people spend doing various activities, including child care or paid work. Zooming in on women living with children under age 13, the researchers compared the time spent parenting among 8,748 mothers in the 2003 to 2005 surveys with 5,007 mothers in the 2015 to 2017 surveys. Parenting activities included reading, arts and crafts, homework, driving to and from extracurricular activities, basic care, such as feeding and dressing, and the time mothers spent on behalf of children, such as researching summer camps.

7-7-21 New Scientist all-day virtual event: What is the future of healthcare?
FROM microrobot surgeons and virtual reality diagnostics to psychedelics, what is the future of healthcare? New Scientist‘s all-day virtual event on 26 June, sponsored by Alzheimer’s Research UK, was filled with inspiring talks from leading experts in health and medicine about the coming revolution in healthcare, with thought-provoking questions from the audience. Viewers had access to a wide range of talks and discussions across three virtual stages, tackling big questions in health and healthcare, including: how we could take vaccine technology to the next level in our battle against covid-19 and other diseases like cancer; the role of genomics and artificial intelligence in healthcare; and how magic mushrooms might form part of a future treatment for depression. It is impossible to talk about health at the moment without considering the enormous impact that the covid-19 pandemic will continue to have globally. On the main stage, Nisreen Alwan at the University of Southampton, UK, explained why countries mustn’t ignore the massive burden of chronic illness, or long covid, that follows acute waves of coronavirus infection. “If somebody survives the infection or the acute illness in the short term, that mustn’t be confused with full recovery,” said Alwan. We need to learn from other chronic conditions, such as myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), she said. There is early evidence that existing covid-19 vaccines may reduce or eliminate symptoms of long covid in some people. Anna Blakney at the University of British Columbia in Vancouver spoke on the mind and body stage about the next generation of mRNA vaccines, including a vaccine containing mRNA that can amplify itself inside cells. It would take just two Olympic swimming pools worth of the Pfizer/BioNTech covid-19 vaccine to fully vaccinate everyone on the planet, said Blakney. “It really puts into perspective how one company would be able to make vaccines for the entire world.”

7-7-21 Why do we experience music that it out of tune as unpleasant?
It depends on what you mean by “out of tune”. If you are referring to melodies, the answer is that people have built-in expectations of how a tune will develop, based on whatever musical scale their culture uses. If we expect a combination of scale sequences (G, A, B, C, for example) and notes that harmonise with one another (such as E, G and C), then a note that isn’t part of the scale sounds irritating. If the question refers to discordant harmonies, the answer is more complex. Whenever two notes sound together, we hear an additional “beat” note whose frequency is the difference between the two. If the two notes are sufficiently far apart, the beat note has a high enough frequency to become subconsciously audible. For example, if you play C and G together, the beat note is another C, an octave below. We experience this coincidence as harmony. A beat note that doesn’t harmonise makes the chord sound ugly. Two notes sound particularly harmonious together when their frequencies have a simple mathematical relationship, such as the frequency of one note being or of the other. For example, the interval between the note A (frequency 440 Hz) and an E (660 Hz) has a ratio of 2:3 and is a perfect fifth. One of the notes between them, C, (550 Hz) forms a major third with the A below (ratio 4:5). Deviations from this sound out of tune. However, music is more complicated than this, and two things that particularly affect our perceptions are whether it matches our expectations, and whether the various musicians are in tune with each other. It is impossible to devise a perfect tuning system and this problem has plagued musicians since the time of Pythagoras. Many tuning systems – known as temperaments – have been devised. To modern Western ears used to instruments tuned using a system known as equal temperament, music played using other tuning systems can sound quite strange and out-of-tune. You can hear this on recordings of Johann Sebastian Bach played on historic Dutch and German organs, for instance. The Highland pipes are another example, because they are tuned to a scale that isn’t used for anything else.

7-7-21 These streets aren't made for walking: Why sidewalks need a rethink
Pavements date back some 2000 years, but are seldom built with pedestrians in mind. Here's why reinvented sidewalks could benefit your joints — and the planet. WHEN Viveca Wallqvist first phoned a local asphalt company, she didn’t mince her words. “I have something to tell you,” she said. “Your material is really hard – too hard. People are getting hurt.” Her comments didn’t go down well. “They were like,’Who is this crazy scientist?,'” she recalls. Asphalt is supposed to be hard, they said. But a few days later, the company rang back. It was the beginning of a journey that could reinvent the ground we walk on. Wallqvist’s passion is rare. It is more than two millennia since the Romans laid their first pavimentum, from where we get the word “pavement”. Since then, very few people have questioned the fact that the pavements we walk on are, in effect, extensions of the road surface, made of stuff with properties that almost exclusively reflected the needs of horse-drawn and then motorised vehicles rather than pedestrians. Wallqvist, a materials chemist at the Research Institutes of Sweden in Stockholm, is determined to change that. Meanwhile, in London, plans are afoot to build a giant research facility to test new, spongier walking surfaces. It is the brainchild of Nick Tyler at University College London, who is also convinced that pavement pounding is harming us. The average person takes around 200 million steps in a lifetime, he notes, and we aren’t evolved to deal with such hard surfaces. So, after waiting more than 2300 years for a pavement evangelist, two have come along at once. You might not read anything into that. On the other hand, perhaps, it’s a sign that sidewalks are about to get a makeover. The Romans were meticulous engineers, famous for their road building. Excavating down almost a metre, they placed flat stones at the bottom, then small stone fragments in mortar. Next came a compacted layer of broken pottery and brick, crushed stone and gravel, mixed with lime mortar. Atop they placed irregular stones about 15 centimetres thick – the pavimentum. This remained the pinnacle of pavement technology until the 18th century, when the first modern roads were built. And it wasn’t until the 19th century that engineers really began to innovate.

7-7-21 What forms can consciousness take and can we see it in our brains?
New insights into the different states of human consciousness and where it occurs in the brain are helping us crack the mystery of what gives rise to felt experience. In essence, consciousness is any kind of subjective experience. Being in pain; smelling onions frying; feeling humiliated; recognising a friend in the crowd; reflecting that you are wiser than you were last year – all of these are examples of conscious experiences. In a field fraught with disagreements, this is something that most, but not all, researchers agree on. Go any deeper, though, and the rifts open up. The 17th-century French philosopher René Descartes famously divided the universe into “matter stuff”, such as rocks and physical bodies, and “mind stuff”. In the 20th century, philosopher David Chalmers at New York University built on Descartes’s separation, known as “dualism”, and the work of later thinkers, to distinguish between “easy problems of consciousness” and “the hard problem”. The easy stuff consists of explaining the brain processes associated with consciousness, such as the integration of sensory information, learning, thinking and being awake or asleep. Though we are making steady progress, these problems have yet to be cracked: they are easy only in the sense that the known strategies of cognitive and neuroscientific research should eventually provide full explanations. The hard problem, which Chalmers introduced at a scientific meeting in 1994, is to explain why and how we have subjective experiences at all. “Consciousness poses the most baffling problem in the science of the mind,” Chalmers said. When we think and perceive, there is a “whir of information-processing” in the brain, as he put it, but also very distinctive subjective states of mind. The puzzle is how a 1.3 kilogram organ with the consistency of tofu can generate the feeling of being.

7-7-21 We need to overhaul the language of genetics to root out racism
UNSHARED science is of little value. The whole scientific endeavour relies on ideas, methods and data being available to all. The words we use are vital to making sure that we are all on the same page and our ideas are conveyed accurately. But in my field of genetics, the language we use isn’t up to scratch. Terms in common usage present problems ranging from being scientifically confused or ambiguous, to being rooted in a racist history that echoes in our present. Every scientific discipline has its own jargon used to summarise or label the complexity of the world. And as our genome is the richest data set we have ever tackled, it is no surprise that human genetics is particularly burdened with terms that strive to encapsulate our ancestry and the secrets of our behaviour, evolution and disease. Genetics is also a field with a pernicious history. Its origins are inextricably entwined with the 18th-century invention of race, then using pigmentation and skull measurements to hierarchically taxonomise people. With that came scientific racism marshalled into the justification of slavery and subjugation, and the eugenics projects of the early 20th century followed not far behind. Contemporary genetics has unequivocally demolished the attempts to use ancestry, anatomy and genetics to assert a biological basis for race. Although people around the world differ, the genetics underlying those differences doesn’t correspond to the racial classification that we use today. “Black” – meaning people of recent African descent – covers more than a billion people with more genetic diversity than the rest of the world put together. From a genetic point of view, it isn’t an informative term. Yet we use it. This is why we call race a “social construct” – race exists because we perceive it, but has no meaningful biological basis.

7-7-21 How antibodies may cause rare blood clots after some COVID-19 vaccines
The shots’ benefits continue to outweigh the risk of the uncommon side effect, experts say. Some COVID-19 vaccines have been linked to dangerous but incredibly rare blood clots. Now a small study is revealing new details on how those clots form. Vaccine-induced antibodies attach to a protein involved in blood clotting at a similar spot that the anticoagulant drug heparin does, spurring platelets to form clots, researchers report July 7 in Nature. Researchers already knew that COVID-19 vaccines developed by Johnson & Johnson and AstraZeneca can sometimes cause the body to make antibodies that attach to a protein called platelet factor 4, or PF4, which then causes platelets to form clots (SN: 4/13/21; SN: 4/7/21; SN: 4/16/21). The vaccine-induced condition is similar to what happens with heparin, a blood thinner that can also attach to PF4. When heparin binds to the protein, some people’s immune systems then attack the bound molecules, a counterintuitive condition called heparin-induced thrombocytopenia also characterized by clotting. Even in light of those similarities, it was still unclear whether antibodies sparked by heparin treatment or COVID-19 vaccines used the same mechanism to prompt platelets to clot. Angela Huynh, a platelet immunologist at McMaster University in Hamilton, Canada, and colleagues analyzed PF4-recognizing antibodies from 10 heparin-induced thrombocytopenia patients and five patients with COVID-19 vaccine–induced clots, a condition called vaccine-induced immune thrombotic thrombocytopenia, or VITT. The immune proteins from VITT patients attached to a similar spot on PF4 as heparin does, hinting that heparin and COVID-19 vaccines cause blood to clot in similar ways. PF4-binding antibodies might not be the whole story when it comes to clotting, the researchers say. Knowing how the clots form could help in treating them.

7-6-21 Researchers say ancient bone carving suggests Neanderthals could make art
Inside a German cave, researchers discovered what they say is one of the oldest pieces of art ever found. It is the toe bone of a prehistoric deer, with lines carved into, the researchers wrote in the journal Nature Ecology & Evolution. They say the lines were made by Neanderthals, and the bone carbon dates to 51,000 years ago. Study co-author Thomas Terberger, a prehistoric archaeologist, told NBC News this is "clearly not a pendant or something like that. It's clearly a decoration with a kind of symbolic character. ... You might even call it the initial start of art, something which was not done by accident, but with a clear plan in mind." It has long been thought that Neanderthals were unable to express symbolism through art, NBC News reports, and the researchers said this is evidence to the contrary. The bone was found in the famed "Unicorn Cave" in central Germany, discovered alongside the shoulder blade bones of a deer and the skull of a cave bear. Fossilized bones have been unearthed in the cave for centuries, and it's been established that Neanderthals lived in the cave from at least 130,000 years ago until 47,000 years ago. Researchers said they don't know if the lines on the toe bone have any meaning, as the object is "quite unique," archaeologist Dirk Leder said. "We don't see it anywhere in the Paleolithic literature. We were discussing different interpretations. ... The shape could be like a female figurine with the head and the chest part, but then the chevron pattern to some of us looked like three mountains in a row, a landscape view."

7-6-21 How Hans Berger’s quest for telepathy spurred modern brain science
Instead of finding long-range signals, he invented EEG. A brush with death led Hans Berger to invent a machine that could eavesdrop on the brain. In 1893, when he was 19, Berger fell off his horse during maneuvers training with the German military and was nearly trampled. On that same day, his sister, far away, got a bad feeling about Hans. She talked her father into sending a telegram asking if everything was all right. To young Berger, this eerie timing was no coincidence: It was a case of “spontaneous telepathy,” he later wrote. Hans was convinced that he had transmitted his thoughts of mortal fear to his sister — somehow. So he decided to study psychiatry, beginning a quest to uncover how thoughts could travel between people. Chasing after a scientific basis for telepathy was a dead end, of course. But in the attempt, Berger ended up making a key contribution to modern medicine and science: He invented the electroencephalogram, or EEG, a device that could read the brain’s electrical activity. Berger’s machine, first used successfully in 1924, produced a readout of squiggles that represented the electricity created by collections of firing nerve cells in the brain. In the century since, the EEG has become an indispensable clinical tool. It can spot seizures, monitor sleep and even help determine brain death. It has also yielded fundamental insights into how the brain works, revealing details about the brain’s activity while at rest, or while crunching numbers or tripping on hallucinogens. When Berger was young, the idea of paranormal psychic communication didn’t sound as wacko as it does now. “The hangover from the 19th century was this idea of trying to explain cases of telepathy,” says communications expert Caitlin Shure, who wrote her thesis at Columbia University on the concept of brain waves. At that time, scientific societies and serious research initiatives were devoted to probing these occurrences. British physician and author Arthur Conan Doyle, of Sherlock Holmes fame, was a staunch believer. It was, as Shure puts it, “peak telepathy enthusiasm time.”

7-6-21 Common colds predate farming and may be older than our species
Common colds and cold sores have afflicted us for at least 31,000 years, according to a study that found DNA from viruses in ancient teeth. What’s more, the sniffles may have plagued us for far longer. The DNA of one virus suggests it first evolved around 700,000 years ago – suggesting viruses that cause colds predate our species, and also troubled our Neanderthal cousins. The preserved virus is “the oldest virus in humans yet”, says Sofie Holtsmark Nielsen, who carried out the work at the University of Copenhagen in Denmark. She and her colleagues studied two fragmented milk teeth that were excavated at Yana in north-east Siberia. The teeth are 31,600 years old, making them the oldest human remains found so far north. Two years ago, researchers led by Martin Sikora, also at the University of Copenhagen, obtained human DNA from the teeth. Holtsmark Nielsen has now revisited the DNA from the teeth to look for genes from infectious organisms. She found low-quality DNA from four species of herpesvirus. These included herpes simplex, the virus that causes cold sores. Her team also recovered two high-quality genomes of human adenovirus C, which today is a common infection. “You almost certainly have had it as a kid, pretty much everyone has been infected with it,” says Holtsmark Nielsen. “It’s usually a bit like a cold.” Previously, the oldest direct evidence of an identifiable virus infecting a human was from just 7000 years ago: researchers found that hepatitis B has been infecting Europeans for at least that long. It has also been possible to identify bacterial infections from within the past 10,000 years, after the advent of farming, but not from earlier periods. “It’s really a remarkable technical accomplishment to be able to extract this kind of information from material that is that old,” says Caitlin Pepperell at the University of Wisconsin-Madison. However, she says it isn’t clear that the ancient viruses only caused mild illnesses, as even today adenovirus and herpesvirus do sometimes cause serious illness.

7-6-21 How wielding lamps and torches shed new light on Stone Age cave art
Experiments with ancient light sources help unravel how people created underground paintings. As a geologist who studies Stone Age cave art, Iñaki Intxaurbe is used to making subterranean treks in a headlamp and boots. But the first time he navigated a cave the way humans thousands of years ago would have — barefoot while holding a torch — he learned two things. “The first sensation is that the ground is very wet and cold,” says Intxaurbe, of the University of the Basque Country in Leioa, Spain. The second: If something chases you, it will be hard to run. “You are not going to see what is in front of you,” he says. Torches are just one of several light sources Stone Age artists used to navigate caves. Intxaurbe and colleagues are wielding these fiery tools in dark, damp and often cramped caves in an effort to understand how and why humans journeyed beneath the earth and why they created art there (SN: 11/7/18). In the wide chambers and narrow passageways of Isuntza I Cave in the Basque region of Spain, the researchers tested torches, stone lamps and fireplaces — nooks in cave walls. Juniper branches, animal fat and other materials that Stone Age humans would have had at hand fueled the light sources. The team measured flame intensity and duration, as well as how far away from the source light illuminated the walls. Each light source comes with its own quirks that make it well suited to specific cave spaces and tasks, the team reports June 16 in PLOS ONE. Stone Age humans would have controlled fire in varying ways to travel through caves and make and view art, the researchers say. Torches work best on the move, as their flames need motion to stay lit and produce a lot of smoke. Though torches cast a wide glow, they burn for an average of just 41 minutes, the team found. That suggests several torches would have been needed to travel through caves. Concave stone lamps filled with animal fat, on the other hand, are smokeless and can offer more than an hour of focused, candlelike light. That would have made it easy to stay in one spot for a while. And while fireplaces produce a lot of light, they can also produce a lot of smoke. That type of light source is best suited for large spaces that get plenty of airflow, the researchers say.

7-5-21 First farmers in the Atacama desert had a history of brutal violence
When coastal hunter-gatherers settled inland to begin farming about 3000 years ago in the Atacama desert, their violence became more gruesome, often with intent to kill, according to a study of human remains from the time. Vivian Standen at the University of Tarapacá in Chile and her colleagues studied signs of violence in the remains of 194 adults buried between 2800 and 1400 years ago in a coastal desert valley of northern Chile. The team discovered that 40 individuals were subjected to brutal levels of violence, 20 of whom died from their injuries. Some bodies still had soft tissue, preserved by the arid desert environment, which offered insight into injuries that would otherwise be unknown. One woman appeared to have sustained a torturous and bizarre attack, her chin’s skin being stretched to cover her mouth, while her top lip covered her nostrils. Distinctive tattoos and analysis of strontium isotopes in her teeth – which can reveal where people lived because the ratio of different isotopes to each other changes based on what they eat and drink – indicated she was possibly an outsider from southern Peru, which may have caused hostility, says Standen. All other people from the group subjected to violence, however, were local. Three people were buried naked in a pit without usual funerary offerings and their skulls were smashed, probably by a stone mace. Strontium analyses indicated they ate more seafood, suggesting they were hunter-gatherers from the nearby coast who were attacked by farmers. Most violence occurred early on when cultivation in the region started, before tailing off as farming communities became more established. A previous study by Standen that looked at coastal hunter-gatherer violence in the same area before farming took off found only three cases that caused death out of 34 dead bodies showing signs of violence.

7-2-21 What experts know so far about the delta variant
The variant is rapidly outcompeting other versions of the coronavirus around the world. Yet another coronavirus variant has public health officials around the globe scrambling to control its spread. The delta variant, which first emerged in India, has now spread to more than 80 countries and is quickly becoming the dominant version of the virus (SN: 5/9/21). In places like the United Kingdom, delta has dethroned the highly transmissible alpha variant, which was first identified in that country, as the most common form of the virus. That rapid spread of the delta variant has forced health officials to react. U.K. officials, for instance, delayed plans to reopen the country, pushing the date back to mid-July. And health officials in Israel, a nation where nearly 60 percent of the population is fully vaccinated, reinstated its requirement that residents wear masks indoors — a public health measure that had been lifted 10 days before. In the United States, places like Los Angeles County recommend that even vaccinated people still wear masks indoors. The World Health Organization also urges everyone to continue wearing masks, though the U.S. Centers for Disease Control and Prevention’s guidelines that vaccinated people can go without masks in most situations remain in place. Delta poses the biggest threat to unvaccinated people, the latest studies suggest. In the United States, delta is responsible for an estimated 26.1 percent of cases across the country. Its prevalence is doubling every two weeks. Narrowing in on regions that include states with low vaccination rates like Missouri and Wyoming reveals that delta is already causing the majority of infections in some places. On July 1, the Biden administration announced that teams of experts equipped with testing supplies and therapeutics would be sent to U.S. hot spots to control outbreaks of delta. The concern is even greater globally. Just 23.4 percent of people around the world have received at least one dose of a COVID-19 vaccine, most of whom reside in wealthy countries. Less than 1 percent of people in lower-income countries have gotten a shot.

7-2-21 Fish covered in tooth-like armour could help reveal how teeth evolved
A pet fish adorned with tooth-like scales is helping biologists tackle a longstanding debate about the origin of teeth, and explore how body structures can be lost and regained during evolution. The suckermouth armoured catfish is commonly found in pet shops and, unusually for a bony fish, has tooth-like structures called odontodes covering its skin. These physically resemble teeth, erupting from thickened patches of skin to form layered structures of pulp, dentine and enamel, and similar genes appear to be active in both during development. But which evolved first, and how did tissues gain or regain them? Their evolutionary history is complicated, because while ancient fish had similar structures, they were lost in most bony fish, but retained in fish with cartilage-based skeletons, like sharks. They re-emerged again independently in four different bony fish groups, including armoured catfish. To find out more, biologists needed the ability to study and manipulate genes in a fish with skin odontodes, but zebrafish, a common model animal for these kinds of experiments, don’t have them. Now Shunsuke Mori and Tetsuya Nakamura at Rutgers, the State University of New Jersey, have analysed gene activity in developing suckermouth armoured catfish skin odontodes. They uncovered a network of genes very similar to those found in developing teeth. “Most of the genes are shared,” says Nakamura. One of these genes, pitx2, is needed for the first steps of tooth development, yet is absent from the skin odontodes of sharks. So Mori and Nakamura used gene silencing techniques to reduce the activity of pitx2 in the catfish and found that the odontodes didn’t develop properly. This showed the gene is needed for catfish skin odontode development, suggesting that evolution had redeployed the tooth genes to recreate skin odontodes in the catfish.

7-1-21 Mini-heart grown in the lab can pump fluid just like the real thing
Stem cells have been used to grow an embryonic-like “heart” that can pump fluid around a system of tiny, fluid-filled channels on a laboratory slide. The mini-heart could allow them to explore how physical forces, such as blood flow, shape the early stages of human heart development and give new insights into congenital heart defects. Current efforts to grow human heart tissue involve coaxing human stem cells to form spheres of heart tissue, known as organoids, in a lab dish. While these offer invaluable insights, they don’t accurately mimic the shape of the heart, which, in the earliest stages of its development, looks like a simple, straight tube. “If we really want to model organ function, we need to figure out how to make these things in the form of tubes,” says David Sachs at the Icahn School of Medicine at Mount Sinai. Sachs and his colleagues seeded human stem cells, known as induced pluripotent stem cells, onto a plastic plate containing tiny wells connected by hair-thin channels. By applying different combinations of chemical signals to different areas of the plate, they were able to get the cells to form tubes made of human heart muscle. The heart tubes pumped fluid around the channels, Sachs told the International Society for Stem Cell Research’s 2021 meeting, held virtually last week. “This is really the very early chapters in the book. But it does set the stage for doing lots of other stuff in the future,” says Christine Mummery at Leiden University Medical Center in the Netherlands. Ultimately, the team aims to grow a mature mini-heart to investigate heart disease and test drugs. They also plan to send it to the International Space Station to help scientists understand why some astronauts working in microgravity develop cardiovascular problems.

7-1-21 A malaria vaccine with live parasites shows promise in a small trial
Next steps include figuring out whether the results hold up in larger trials. In a one-two punch, a malaria vaccine in development pairs a shot of the live parasite that causes the disease with a whammy of infection-fighting drugs to immediately quell it. The candidate is the latest vaccine to show promise against a formidable foe, bolstering hopes that an effective shot might be on the horizon. Malaria, a disease caused by the parasite Plasmodium falciparum, affects more than 200 million people around the world every year. In 2019, an estimated 409,000 people died from the mosquito-borne disease, 67 percent of whom were children younger than 5. The live parasite vaccine and drug combo showed 87.5 percent efficacy in a small group of healthy adult participants, researchers reported June 30 in Nature. The live parasite shot — which is followed by a dose of one of two anti-malarial drugs to eliminate the infection — not only protected people from the same strain included in the vaccine, but most people could also fend off a different parasite strain that circulates in Brazil. If the results hold up in a larger study, “it would be fantastic,” says Wilfred Ndifon, a mathematical biologist at the African Institute for Mathematical Sciences in Kigali, Rwanda, who was not involved in the study. Even as newly emerging diseases like COVID-19 have killed millions and martialed global attention and resources, “we are still falling short of controlling the ones that already exist,” Ndifon says. Currently there is only one malaria vaccine, called RTS,S, in use in Africa that provides partial protection in young children. Rather than live parasites, the shot uses a key malaria protein that helps the parasite infect liver cells to train the body to recognize the pathogen. In a late-stage clinical trial, it prevented 39 percent of malaria cases among children 5 to 17 years old. Now, it’s given to children in Ghana, Malawi and Kenya as part of a pilot program through the World Health Organization.

7-1-21 Fossilized dung from a dinosaur ancestor yields a new beetle species
Ancient feces could contain more details about life long ago than previously thought. In a fossilized chunk of ancient reptilian poo, scientists have uncovered complete specimens of a new beetle species. The finding, described June 30 in Current Biology, suggests that fossilized dung could contain more details about past life than previously thought. Such ancient feces have been “largely overlooked,” says evolutionary biologist Martin Qvarnström of Uppsala University in Sweden. “But they often contain very well-preserved fossils. They’re like hidden treasure chests.” Fossilized dung, also known as coprolite, can reveal insights about the diets of extinct creatures that body fossils can’t. For example, coprolites have been used to show that some dinosaurs with plant-based diets also ate crustaceans (SN: 9/21/17). Feces, especially from carnivores, can readily form into coprolites because the excrement often contains the raw materials and bacteria needed for mineralization, says paleontologist Karen Chin of the University of Colorado Boulder, who was not involved in the study. Laboratory experiments have shown that poo can become a coprolite in just weeks, saving any delicate structures within as the dung is buried over time. “If you didn’t get rapid mineralization, the feces would get flattened, but most coprolites are three-dimensional,” she says. Despite this preservation power, coprolites can be overshadowed by amber, a translucent tree resin, when it comes to fossils. Some of the most well-preserved, three-dimensional insect fossils are found in amber. But since the resin became common only around 130 million years ago, amber-preserved insects older than that are rare. Curious whether much older, fossilized poop could match the fossil quality of amber specimens, Qvarnström and colleagues used a synchrotron, which generates powerful X-rays, to peek inside a coprolite from Poland. The dung likely comes from an extinct dinosaur relative called Silesaurus opolensis, which lived around 237 million to 227 million years ago during the Triassic Period.

75 Evolution News Articles
for July 2021

Evolution News Articles for June 2021